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v4.17
 
   1/* A network driver using virtio.
   2 *
   3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17 */
  18//#define DEBUG
  19#include <linux/netdevice.h>
  20#include <linux/etherdevice.h>
  21#include <linux/ethtool.h>
  22#include <linux/module.h>
  23#include <linux/virtio.h>
  24#include <linux/virtio_net.h>
  25#include <linux/bpf.h>
  26#include <linux/bpf_trace.h>
  27#include <linux/scatterlist.h>
  28#include <linux/if_vlan.h>
  29#include <linux/slab.h>
  30#include <linux/cpu.h>
  31#include <linux/average.h>
  32#include <linux/filter.h>
 
  33#include <net/route.h>
  34#include <net/xdp.h>
 
  35
  36static int napi_weight = NAPI_POLL_WEIGHT;
  37module_param(napi_weight, int, 0444);
  38
  39static bool csum = true, gso = true, napi_tx;
  40module_param(csum, bool, 0444);
  41module_param(gso, bool, 0444);
  42module_param(napi_tx, bool, 0644);
  43
  44/* FIXME: MTU in config. */
  45#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  46#define GOOD_COPY_LEN	128
  47
  48#define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
  49
  50/* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
  51#define VIRTIO_XDP_HEADROOM 256
  52
 
 
 
 
 
 
  53/* RX packet size EWMA. The average packet size is used to determine the packet
  54 * buffer size when refilling RX rings. As the entire RX ring may be refilled
  55 * at once, the weight is chosen so that the EWMA will be insensitive to short-
  56 * term, transient changes in packet size.
  57 */
  58DECLARE_EWMA(pkt_len, 0, 64)
  59
  60#define VIRTNET_DRIVER_VERSION "1.0.0"
  61
  62static const unsigned long guest_offloads[] = {
  63	VIRTIO_NET_F_GUEST_TSO4,
  64	VIRTIO_NET_F_GUEST_TSO6,
  65	VIRTIO_NET_F_GUEST_ECN,
  66	VIRTIO_NET_F_GUEST_UFO
 
 
 
  67};
  68
 
 
 
 
 
 
 
  69struct virtnet_stat_desc {
  70	char desc[ETH_GSTRING_LEN];
  71	size_t offset;
  72};
  73
  74struct virtnet_sq_stats {
  75	struct u64_stats_sync syncp;
  76	u64 packets;
  77	u64 bytes;
 
 
 
 
  78};
  79
  80struct virtnet_rq_stats {
  81	struct u64_stats_sync syncp;
  82	u64 packets;
  83	u64 bytes;
 
 
 
 
 
 
  84};
  85
  86#define VIRTNET_SQ_STAT(m)	offsetof(struct virtnet_sq_stats, m)
  87#define VIRTNET_RQ_STAT(m)	offsetof(struct virtnet_rq_stats, m)
  88
  89static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
  90	{ "packets",	VIRTNET_SQ_STAT(packets) },
  91	{ "bytes",	VIRTNET_SQ_STAT(bytes) },
 
 
 
 
  92};
  93
  94static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
  95	{ "packets",	VIRTNET_RQ_STAT(packets) },
  96	{ "bytes",	VIRTNET_RQ_STAT(bytes) },
 
 
 
 
 
 
  97};
  98
  99#define VIRTNET_SQ_STATS_LEN	ARRAY_SIZE(virtnet_sq_stats_desc)
 100#define VIRTNET_RQ_STATS_LEN	ARRAY_SIZE(virtnet_rq_stats_desc)
 101
 102/* Internal representation of a send virtqueue */
 103struct send_queue {
 104	/* Virtqueue associated with this send _queue */
 105	struct virtqueue *vq;
 106
 107	/* TX: fragments + linear part + virtio header */
 108	struct scatterlist sg[MAX_SKB_FRAGS + 2];
 109
 110	/* Name of the send queue: output.$index */
 111	char name[40];
 112
 113	struct virtnet_sq_stats stats;
 114
 115	struct napi_struct napi;
 
 
 
 116};
 117
 118/* Internal representation of a receive virtqueue */
 119struct receive_queue {
 120	/* Virtqueue associated with this receive_queue */
 121	struct virtqueue *vq;
 122
 123	struct napi_struct napi;
 124
 125	struct bpf_prog __rcu *xdp_prog;
 126
 127	struct virtnet_rq_stats stats;
 128
 129	/* Chain pages by the private ptr. */
 130	struct page *pages;
 131
 132	/* Average packet length for mergeable receive buffers. */
 133	struct ewma_pkt_len mrg_avg_pkt_len;
 134
 135	/* Page frag for packet buffer allocation. */
 136	struct page_frag alloc_frag;
 137
 138	/* RX: fragments + linear part + virtio header */
 139	struct scatterlist sg[MAX_SKB_FRAGS + 2];
 140
 141	/* Min single buffer size for mergeable buffers case. */
 142	unsigned int min_buf_len;
 143
 144	/* Name of this receive queue: input.$index */
 145	char name[40];
 146
 147	struct xdp_rxq_info xdp_rxq;
 148};
 149
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 150/* Control VQ buffers: protected by the rtnl lock */
 151struct control_buf {
 152	struct virtio_net_ctrl_hdr hdr;
 153	virtio_net_ctrl_ack status;
 154	struct virtio_net_ctrl_mq mq;
 155	u8 promisc;
 156	u8 allmulti;
 157	__virtio16 vid;
 158	__virtio64 offloads;
 
 159};
 160
 161struct virtnet_info {
 162	struct virtio_device *vdev;
 163	struct virtqueue *cvq;
 164	struct net_device *dev;
 165	struct send_queue *sq;
 166	struct receive_queue *rq;
 167	unsigned int status;
 168
 169	/* Max # of queue pairs supported by the device */
 170	u16 max_queue_pairs;
 171
 172	/* # of queue pairs currently used by the driver */
 173	u16 curr_queue_pairs;
 174
 175	/* # of XDP queue pairs currently used by the driver */
 176	u16 xdp_queue_pairs;
 177
 
 
 
 178	/* I like... big packets and I cannot lie! */
 179	bool big_packets;
 180
 
 
 
 181	/* Host will merge rx buffers for big packets (shake it! shake it!) */
 182	bool mergeable_rx_bufs;
 183
 
 
 
 
 
 
 
 
 184	/* Has control virtqueue */
 185	bool has_cvq;
 186
 187	/* Host can handle any s/g split between our header and packet data */
 188	bool any_header_sg;
 189
 190	/* Packet virtio header size */
 191	u8 hdr_len;
 192
 193	/* Work struct for refilling if we run low on memory. */
 194	struct delayed_work refill;
 195
 
 
 
 
 
 
 196	/* Work struct for config space updates */
 197	struct work_struct config_work;
 198
 199	/* Does the affinity hint is set for virtqueues? */
 200	bool affinity_hint_set;
 201
 202	/* CPU hotplug instances for online & dead */
 203	struct hlist_node node;
 204	struct hlist_node node_dead;
 205
 206	struct control_buf *ctrl;
 207
 208	/* Ethtool settings */
 209	u8 duplex;
 210	u32 speed;
 211
 
 
 
 
 
 
 212	unsigned long guest_offloads;
 
 
 
 
 213};
 214
 215struct padded_vnet_hdr {
 216	struct virtio_net_hdr_mrg_rxbuf hdr;
 217	/*
 218	 * hdr is in a separate sg buffer, and data sg buffer shares same page
 219	 * with this header sg. This padding makes next sg 16 byte aligned
 220	 * after the header.
 221	 */
 222	char padding[4];
 223};
 224
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 225/* Converting between virtqueue no. and kernel tx/rx queue no.
 226 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 227 */
 228static int vq2txq(struct virtqueue *vq)
 229{
 230	return (vq->index - 1) / 2;
 231}
 232
 233static int txq2vq(int txq)
 234{
 235	return txq * 2 + 1;
 236}
 237
 238static int vq2rxq(struct virtqueue *vq)
 239{
 240	return vq->index / 2;
 241}
 242
 243static int rxq2vq(int rxq)
 244{
 245	return rxq * 2;
 246}
 247
 248static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 249{
 250	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 251}
 252
 253/*
 254 * private is used to chain pages for big packets, put the whole
 255 * most recent used list in the beginning for reuse
 256 */
 257static void give_pages(struct receive_queue *rq, struct page *page)
 258{
 259	struct page *end;
 260
 261	/* Find end of list, sew whole thing into vi->rq.pages. */
 262	for (end = page; end->private; end = (struct page *)end->private);
 263	end->private = (unsigned long)rq->pages;
 264	rq->pages = page;
 265}
 266
 267static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 268{
 269	struct page *p = rq->pages;
 270
 271	if (p) {
 272		rq->pages = (struct page *)p->private;
 273		/* clear private here, it is used to chain pages */
 274		p->private = 0;
 275	} else
 276		p = alloc_page(gfp_mask);
 277	return p;
 278}
 279
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 280static void virtqueue_napi_schedule(struct napi_struct *napi,
 281				    struct virtqueue *vq)
 282{
 283	if (napi_schedule_prep(napi)) {
 284		virtqueue_disable_cb(vq);
 285		__napi_schedule(napi);
 286	}
 287}
 288
 289static void virtqueue_napi_complete(struct napi_struct *napi,
 290				    struct virtqueue *vq, int processed)
 291{
 292	int opaque;
 293
 294	opaque = virtqueue_enable_cb_prepare(vq);
 295	if (napi_complete_done(napi, processed)) {
 296		if (unlikely(virtqueue_poll(vq, opaque)))
 297			virtqueue_napi_schedule(napi, vq);
 298	} else {
 299		virtqueue_disable_cb(vq);
 300	}
 301}
 302
 303static void skb_xmit_done(struct virtqueue *vq)
 304{
 305	struct virtnet_info *vi = vq->vdev->priv;
 306	struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
 307
 308	/* Suppress further interrupts. */
 309	virtqueue_disable_cb(vq);
 310
 311	if (napi->weight)
 312		virtqueue_napi_schedule(napi, vq);
 313	else
 314		/* We were probably waiting for more output buffers. */
 315		netif_wake_subqueue(vi->dev, vq2txq(vq));
 316}
 317
 318#define MRG_CTX_HEADER_SHIFT 22
 319static void *mergeable_len_to_ctx(unsigned int truesize,
 320				  unsigned int headroom)
 321{
 322	return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
 323}
 324
 325static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 326{
 327	return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 328}
 329
 330static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
 331{
 332	return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
 333}
 334
 335/* Called from bottom half context */
 336static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 337				   struct receive_queue *rq,
 338				   struct page *page, unsigned int offset,
 339				   unsigned int len, unsigned int truesize)
 
 
 340{
 341	struct sk_buff *skb;
 342	struct virtio_net_hdr_mrg_rxbuf *hdr;
 343	unsigned int copy, hdr_len, hdr_padded_len;
 344	char *p;
 
 
 345
 346	p = page_address(page) + offset;
 347
 348	/* copy small packet so we can reuse these pages for small data */
 349	skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 350	if (unlikely(!skb))
 351		return NULL;
 352
 353	hdr = skb_vnet_hdr(skb);
 354
 355	hdr_len = vi->hdr_len;
 356	if (vi->mergeable_rx_bufs)
 357		hdr_padded_len = sizeof(*hdr);
 358	else
 359		hdr_padded_len = sizeof(struct padded_vnet_hdr);
 360
 361	memcpy(hdr, p, hdr_len);
 
 
 
 
 
 
 
 
 
 362
 363	len -= hdr_len;
 364	offset += hdr_padded_len;
 365	p += hdr_padded_len;
 
 366
 367	copy = len;
 368	if (copy > skb_tailroom(skb))
 369		copy = skb_tailroom(skb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 370	skb_put_data(skb, p, copy);
 371
 372	len -= copy;
 373	offset += copy;
 374
 375	if (vi->mergeable_rx_bufs) {
 376		if (len)
 377			skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 378		else
 379			put_page(page);
 380		return skb;
 381	}
 382
 383	/*
 384	 * Verify that we can indeed put this data into a skb.
 385	 * This is here to handle cases when the device erroneously
 386	 * tries to receive more than is possible. This is usually
 387	 * the case of a broken device.
 388	 */
 389	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 390		net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 391		dev_kfree_skb(skb);
 392		return NULL;
 393	}
 394	BUG_ON(offset >= PAGE_SIZE);
 395	while (len) {
 396		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 397		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 398				frag_size, truesize);
 399		len -= frag_size;
 400		page = (struct page *)page->private;
 401		offset = 0;
 402	}
 403
 404	if (page)
 405		give_pages(rq, page);
 406
 407	return skb;
 408}
 409
 410static void virtnet_xdp_flush(struct net_device *dev)
 411{
 412	struct virtnet_info *vi = netdev_priv(dev);
 413	struct send_queue *sq;
 414	unsigned int qp;
 415
 416	qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
 417	sq = &vi->sq[qp];
 
 
 418
 419	virtqueue_kick(sq->vq);
 420}
 421
 422static bool __virtnet_xdp_xmit(struct virtnet_info *vi,
 423			       struct xdp_buff *xdp)
 
 424{
 425	struct virtio_net_hdr_mrg_rxbuf *hdr;
 426	unsigned int len;
 427	struct send_queue *sq;
 428	unsigned int qp;
 429	void *xdp_sent;
 430	int err;
 431
 432	qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
 433	sq = &vi->sq[qp];
 434
 435	/* Free up any pending old buffers before queueing new ones. */
 436	while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 437		struct page *sent_page = virt_to_head_page(xdp_sent);
 438
 439		put_page(sent_page);
 440	}
 441
 442	xdp->data -= vi->hdr_len;
 443	/* Zero header and leave csum up to XDP layers */
 444	hdr = xdp->data;
 445	memset(hdr, 0, vi->hdr_len);
 
 446
 447	sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data);
 448
 449	err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp->data, GFP_ATOMIC);
 
 450	if (unlikely(err))
 451		return false; /* Caller handle free/refcnt */
 452
 453	return true;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 454}
 455
 456static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp)
 
 457{
 458	struct virtnet_info *vi = netdev_priv(dev);
 459	struct receive_queue *rq = vi->rq;
 460	struct bpf_prog *xdp_prog;
 461	bool sent;
 
 
 
 
 
 
 
 
 462
 463	/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 464	 * indicate XDP resources have been successfully allocated.
 465	 */
 466	xdp_prog = rcu_dereference(rq->xdp_prog);
 467	if (!xdp_prog)
 468		return -ENXIO;
 469
 470	sent = __virtnet_xdp_xmit(vi, xdp);
 471	if (!sent)
 472		return -ENOSPC;
 473	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 474}
 475
 476static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
 477{
 478	return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
 479}
 480
 481/* We copy the packet for XDP in the following cases:
 482 *
 483 * 1) Packet is scattered across multiple rx buffers.
 484 * 2) Headroom space is insufficient.
 485 *
 486 * This is inefficient but it's a temporary condition that
 487 * we hit right after XDP is enabled and until queue is refilled
 488 * with large buffers with sufficient headroom - so it should affect
 489 * at most queue size packets.
 490 * Afterwards, the conditions to enable
 491 * XDP should preclude the underlying device from sending packets
 492 * across multiple buffers (num_buf > 1), and we make sure buffers
 493 * have enough headroom.
 494 */
 495static struct page *xdp_linearize_page(struct receive_queue *rq,
 496				       u16 *num_buf,
 497				       struct page *p,
 498				       int offset,
 499				       int page_off,
 500				       unsigned int *len)
 501{
 502	struct page *page = alloc_page(GFP_ATOMIC);
 503
 504	if (!page)
 505		return NULL;
 506
 507	memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 508	page_off += *len;
 509
 510	while (--*num_buf) {
 511		int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 512		unsigned int buflen;
 513		void *buf;
 514		int off;
 515
 516		buf = virtqueue_get_buf(rq->vq, &buflen);
 517		if (unlikely(!buf))
 518			goto err_buf;
 519
 520		p = virt_to_head_page(buf);
 521		off = buf - page_address(p);
 522
 523		/* guard against a misconfigured or uncooperative backend that
 524		 * is sending packet larger than the MTU.
 525		 */
 526		if ((page_off + buflen + tailroom) > PAGE_SIZE) {
 527			put_page(p);
 528			goto err_buf;
 529		}
 530
 531		memcpy(page_address(page) + page_off,
 532		       page_address(p) + off, buflen);
 533		page_off += buflen;
 534		put_page(p);
 535	}
 536
 537	/* Headroom does not contribute to packet length */
 538	*len = page_off - VIRTIO_XDP_HEADROOM;
 539	return page;
 540err_buf:
 541	__free_pages(page, 0);
 542	return NULL;
 543}
 544
 545static struct sk_buff *receive_small(struct net_device *dev,
 546				     struct virtnet_info *vi,
 547				     struct receive_queue *rq,
 548				     void *buf, void *ctx,
 549				     unsigned int len,
 550				     bool *xdp_xmit)
 
 551{
 552	struct sk_buff *skb;
 553	struct bpf_prog *xdp_prog;
 554	unsigned int xdp_headroom = (unsigned long)ctx;
 555	unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
 556	unsigned int headroom = vi->hdr_len + header_offset;
 557	unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 558			      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 559	struct page *page = virt_to_head_page(buf);
 560	unsigned int delta = 0;
 561	struct page *xdp_page;
 562	bool sent;
 563	int err;
 
 564
 565	len -= vi->hdr_len;
 
 
 
 
 
 
 
 
 
 
 
 
 
 566
 567	rcu_read_lock();
 568	xdp_prog = rcu_dereference(rq->xdp_prog);
 569	if (xdp_prog) {
 570		struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
 
 571		struct xdp_buff xdp;
 572		void *orig_data;
 573		u32 act;
 574
 575		if (unlikely(hdr->hdr.gso_type))
 576			goto err_xdp;
 577
 578		if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
 579			int offset = buf - page_address(page) + header_offset;
 580			unsigned int tlen = len + vi->hdr_len;
 581			u16 num_buf = 1;
 582
 583			xdp_headroom = virtnet_get_headroom(vi);
 584			header_offset = VIRTNET_RX_PAD + xdp_headroom;
 585			headroom = vi->hdr_len + header_offset;
 586			buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 587				 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 588			xdp_page = xdp_linearize_page(rq, &num_buf, page,
 589						      offset, header_offset,
 590						      &tlen);
 591			if (!xdp_page)
 592				goto err_xdp;
 593
 594			buf = page_address(xdp_page);
 595			put_page(page);
 596			page = xdp_page;
 597		}
 598
 599		xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
 600		xdp.data = xdp.data_hard_start + xdp_headroom;
 601		xdp_set_data_meta_invalid(&xdp);
 602		xdp.data_end = xdp.data + len;
 603		xdp.rxq = &rq->xdp_rxq;
 604		orig_data = xdp.data;
 605		act = bpf_prog_run_xdp(xdp_prog, &xdp);
 
 606
 607		switch (act) {
 608		case XDP_PASS:
 609			/* Recalculate length in case bpf program changed it */
 610			delta = orig_data - xdp.data;
 
 
 611			break;
 612		case XDP_TX:
 613			sent = __virtnet_xdp_xmit(vi, &xdp);
 614			if (unlikely(!sent)) {
 
 
 
 
 
 
 615				trace_xdp_exception(vi->dev, xdp_prog, act);
 616				goto err_xdp;
 617			}
 618			*xdp_xmit = true;
 619			rcu_read_unlock();
 620			goto xdp_xmit;
 621		case XDP_REDIRECT:
 
 622			err = xdp_do_redirect(dev, &xdp, xdp_prog);
 623			if (err)
 624				goto err_xdp;
 625			*xdp_xmit = true;
 626			rcu_read_unlock();
 627			goto xdp_xmit;
 628		default:
 629			bpf_warn_invalid_xdp_action(act);
 
 630		case XDP_ABORTED:
 631			trace_xdp_exception(vi->dev, xdp_prog, act);
 
 632		case XDP_DROP:
 633			goto err_xdp;
 634		}
 635	}
 636	rcu_read_unlock();
 637
 
 638	skb = build_skb(buf, buflen);
 639	if (!skb) {
 640		put_page(page);
 641		goto err;
 642	}
 643	skb_reserve(skb, headroom - delta);
 644	skb_put(skb, len + delta);
 645	if (!delta) {
 646		buf += header_offset;
 647		memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
 648	} /* keep zeroed vnet hdr since packet was changed by bpf */
 
 
 
 649
 650err:
 651	return skb;
 652
 653err_xdp:
 654	rcu_read_unlock();
 655	dev->stats.rx_dropped++;
 
 
 656	put_page(page);
 657xdp_xmit:
 658	return NULL;
 659}
 660
 661static struct sk_buff *receive_big(struct net_device *dev,
 662				   struct virtnet_info *vi,
 663				   struct receive_queue *rq,
 664				   void *buf,
 665				   unsigned int len)
 
 666{
 667	struct page *page = buf;
 668	struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 
 669
 
 670	if (unlikely(!skb))
 671		goto err;
 672
 673	return skb;
 674
 675err:
 676	dev->stats.rx_dropped++;
 677	give_pages(rq, page);
 678	return NULL;
 679}
 680
 681static struct sk_buff *receive_mergeable(struct net_device *dev,
 682					 struct virtnet_info *vi,
 683					 struct receive_queue *rq,
 684					 void *buf,
 685					 void *ctx,
 686					 unsigned int len,
 687					 bool *xdp_xmit)
 
 688{
 689	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 690	u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 691	struct page *page = virt_to_head_page(buf);
 692	int offset = buf - page_address(page);
 693	struct sk_buff *head_skb, *curr_skb;
 694	struct bpf_prog *xdp_prog;
 695	unsigned int truesize;
 696	unsigned int headroom = mergeable_ctx_to_headroom(ctx);
 697	bool sent;
 
 698	int err;
 699
 700	head_skb = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 701
 702	rcu_read_lock();
 703	xdp_prog = rcu_dereference(rq->xdp_prog);
 704	if (xdp_prog) {
 
 705		struct page *xdp_page;
 706		struct xdp_buff xdp;
 707		void *data;
 708		u32 act;
 709
 710		/* Transient failure which in theory could occur if
 711		 * in-flight packets from before XDP was enabled reach
 712		 * the receive path after XDP is loaded.
 713		 */
 714		if (unlikely(hdr->hdr.gso_type))
 715			goto err_xdp;
 716
 
 
 
 
 
 717		/* This happens when rx buffer size is underestimated
 718		 * or headroom is not enough because of the buffer
 719		 * was refilled before XDP is set. This should only
 720		 * happen for the first several packets, so we don't
 721		 * care much about its performance.
 722		 */
 723		if (unlikely(num_buf > 1 ||
 724			     headroom < virtnet_get_headroom(vi))) {
 725			/* linearize data for XDP */
 726			xdp_page = xdp_linearize_page(rq, &num_buf,
 727						      page, offset,
 728						      VIRTIO_XDP_HEADROOM,
 729						      &len);
 
 
 730			if (!xdp_page)
 731				goto err_xdp;
 732			offset = VIRTIO_XDP_HEADROOM;
 733		} else {
 734			xdp_page = page;
 735		}
 736
 737		/* Allow consuming headroom but reserve enough space to push
 738		 * the descriptor on if we get an XDP_TX return code.
 739		 */
 740		data = page_address(xdp_page) + offset;
 741		xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
 742		xdp.data = data + vi->hdr_len;
 743		xdp_set_data_meta_invalid(&xdp);
 744		xdp.data_end = xdp.data + (len - vi->hdr_len);
 745		xdp.rxq = &rq->xdp_rxq;
 746
 747		act = bpf_prog_run_xdp(xdp_prog, &xdp);
 
 748
 749		switch (act) {
 750		case XDP_PASS:
 
 
 751			/* recalculate offset to account for any header
 752			 * adjustments. Note other cases do not build an
 753			 * skb and avoid using offset
 
 754			 */
 755			offset = xdp.data -
 756					page_address(xdp_page) - vi->hdr_len;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 757
 758			/* We can only create skb based on xdp_page. */
 759			if (unlikely(xdp_page != page)) {
 760				rcu_read_unlock();
 761				put_page(page);
 762				head_skb = page_to_skb(vi, rq, xdp_page,
 763						       offset, len, PAGE_SIZE);
 
 
 764				return head_skb;
 765			}
 766			break;
 767		case XDP_TX:
 768			sent = __virtnet_xdp_xmit(vi, &xdp);
 769			if (unlikely(!sent)) {
 
 
 
 
 
 
 
 
 
 770				trace_xdp_exception(vi->dev, xdp_prog, act);
 771				if (unlikely(xdp_page != page))
 772					put_page(xdp_page);
 773				goto err_xdp;
 774			}
 775			*xdp_xmit = true;
 776			if (unlikely(xdp_page != page))
 777				put_page(page);
 778			rcu_read_unlock();
 779			goto xdp_xmit;
 780		case XDP_REDIRECT:
 
 781			err = xdp_do_redirect(dev, &xdp, xdp_prog);
 782			if (err) {
 783				if (unlikely(xdp_page != page))
 784					put_page(xdp_page);
 785				goto err_xdp;
 786			}
 787			*xdp_xmit = true;
 788			if (unlikely(xdp_page != page))
 789				put_page(page);
 790			rcu_read_unlock();
 791			goto xdp_xmit;
 792		default:
 793			bpf_warn_invalid_xdp_action(act);
 
 794		case XDP_ABORTED:
 795			trace_xdp_exception(vi->dev, xdp_prog, act);
 
 796		case XDP_DROP:
 797			if (unlikely(xdp_page != page))
 798				__free_pages(xdp_page, 0);
 799			goto err_xdp;
 800		}
 801	}
 802	rcu_read_unlock();
 803
 804	truesize = mergeable_ctx_to_truesize(ctx);
 805	if (unlikely(len > truesize)) {
 806		pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 807			 dev->name, len, (unsigned long)ctx);
 808		dev->stats.rx_length_errors++;
 809		goto err_skb;
 810	}
 811
 812	head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
 813	curr_skb = head_skb;
 814
 815	if (unlikely(!curr_skb))
 816		goto err_skb;
 817	while (--num_buf) {
 818		int num_skb_frags;
 819
 820		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
 821		if (unlikely(!buf)) {
 822			pr_debug("%s: rx error: %d buffers out of %d missing\n",
 823				 dev->name, num_buf,
 824				 virtio16_to_cpu(vi->vdev,
 825						 hdr->num_buffers));
 826			dev->stats.rx_length_errors++;
 827			goto err_buf;
 828		}
 829
 
 830		page = virt_to_head_page(buf);
 831
 832		truesize = mergeable_ctx_to_truesize(ctx);
 833		if (unlikely(len > truesize)) {
 834			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 835				 dev->name, len, (unsigned long)ctx);
 836			dev->stats.rx_length_errors++;
 837			goto err_skb;
 838		}
 839
 840		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 841		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 842			struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 843
 844			if (unlikely(!nskb))
 845				goto err_skb;
 846			if (curr_skb == head_skb)
 847				skb_shinfo(curr_skb)->frag_list = nskb;
 848			else
 849				curr_skb->next = nskb;
 850			curr_skb = nskb;
 851			head_skb->truesize += nskb->truesize;
 852			num_skb_frags = 0;
 853		}
 854		if (curr_skb != head_skb) {
 855			head_skb->data_len += len;
 856			head_skb->len += len;
 857			head_skb->truesize += truesize;
 858		}
 859		offset = buf - page_address(page);
 860		if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 861			put_page(page);
 862			skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 863					     len, truesize);
 864		} else {
 865			skb_add_rx_frag(curr_skb, num_skb_frags, page,
 866					offset, len, truesize);
 867		}
 868	}
 869
 870	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 871	return head_skb;
 872
 873err_xdp:
 874	rcu_read_unlock();
 
 875err_skb:
 876	put_page(page);
 877	while (num_buf-- > 1) {
 878		buf = virtqueue_get_buf(rq->vq, &len);
 879		if (unlikely(!buf)) {
 880			pr_debug("%s: rx error: %d buffers missing\n",
 881				 dev->name, num_buf);
 882			dev->stats.rx_length_errors++;
 883			break;
 884		}
 
 885		page = virt_to_head_page(buf);
 886		put_page(page);
 887	}
 888err_buf:
 889	dev->stats.rx_dropped++;
 890	dev_kfree_skb(head_skb);
 891xdp_xmit:
 892	return NULL;
 893}
 894
 895static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 896		       void *buf, unsigned int len, void **ctx, bool *xdp_xmit)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 897{
 898	struct net_device *dev = vi->dev;
 899	struct sk_buff *skb;
 900	struct virtio_net_hdr_mrg_rxbuf *hdr;
 901	int ret;
 902
 903	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 904		pr_debug("%s: short packet %i\n", dev->name, len);
 905		dev->stats.rx_length_errors++;
 906		if (vi->mergeable_rx_bufs) {
 907			put_page(virt_to_head_page(buf));
 908		} else if (vi->big_packets) {
 909			give_pages(rq, buf);
 910		} else {
 911			put_page(virt_to_head_page(buf));
 912		}
 913		return 0;
 914	}
 915
 916	if (vi->mergeable_rx_bufs)
 917		skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit);
 
 918	else if (vi->big_packets)
 919		skb = receive_big(dev, vi, rq, buf, len);
 920	else
 921		skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit);
 922
 923	if (unlikely(!skb))
 924		return 0;
 925
 926	hdr = skb_vnet_hdr(skb);
 927
 928	ret = skb->len;
 929
 930	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 931		skb->ip_summed = CHECKSUM_UNNECESSARY;
 932
 933	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
 934				  virtio_is_little_endian(vi->vdev))) {
 935		net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
 936				     dev->name, hdr->hdr.gso_type,
 937				     hdr->hdr.gso_size);
 938		goto frame_err;
 939	}
 940
 
 941	skb->protocol = eth_type_trans(skb, dev);
 942	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 943		 ntohs(skb->protocol), skb->len, skb->pkt_type);
 944
 945	napi_gro_receive(&rq->napi, skb);
 946	return ret;
 947
 948frame_err:
 949	dev->stats.rx_frame_errors++;
 950	dev_kfree_skb(skb);
 951	return 0;
 952}
 953
 954/* Unlike mergeable buffers, all buffers are allocated to the
 955 * same size, except for the headroom. For this reason we do
 956 * not need to use  mergeable_len_to_ctx here - it is enough
 957 * to store the headroom as the context ignoring the truesize.
 958 */
 959static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 960			     gfp_t gfp)
 961{
 962	struct page_frag *alloc_frag = &rq->alloc_frag;
 963	char *buf;
 964	unsigned int xdp_headroom = virtnet_get_headroom(vi);
 965	void *ctx = (void *)(unsigned long)xdp_headroom;
 966	int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
 967	int err;
 968
 969	len = SKB_DATA_ALIGN(len) +
 970	      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 971	if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 972		return -ENOMEM;
 973
 974	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 975	get_page(alloc_frag->page);
 976	alloc_frag->offset += len;
 977	sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
 978		    vi->hdr_len + GOOD_PACKET_LEN);
 979	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
 980	if (err < 0)
 981		put_page(virt_to_head_page(buf));
 982	return err;
 983}
 984
 985static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 986			   gfp_t gfp)
 987{
 988	struct page *first, *list = NULL;
 989	char *p;
 990	int i, err, offset;
 991
 992	sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 993
 994	/* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 995	for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 996		first = get_a_page(rq, gfp);
 997		if (!first) {
 998			if (list)
 999				give_pages(rq, list);
1000			return -ENOMEM;
1001		}
1002		sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1003
1004		/* chain new page in list head to match sg */
1005		first->private = (unsigned long)list;
1006		list = first;
1007	}
1008
1009	first = get_a_page(rq, gfp);
1010	if (!first) {
1011		give_pages(rq, list);
1012		return -ENOMEM;
1013	}
1014	p = page_address(first);
1015
1016	/* rq->sg[0], rq->sg[1] share the same page */
1017	/* a separated rq->sg[0] for header - required in case !any_header_sg */
1018	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1019
1020	/* rq->sg[1] for data packet, from offset */
1021	offset = sizeof(struct padded_vnet_hdr);
1022	sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1023
1024	/* chain first in list head */
1025	first->private = (unsigned long)list;
1026	err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1027				  first, gfp);
1028	if (err < 0)
1029		give_pages(rq, first);
1030
1031	return err;
1032}
1033
1034static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1035					  struct ewma_pkt_len *avg_pkt_len,
1036					  unsigned int room)
1037{
1038	const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 
1039	unsigned int len;
1040
1041	if (room)
1042		return PAGE_SIZE - room;
1043
1044	len = hdr_len +	clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1045				rq->min_buf_len, PAGE_SIZE - hdr_len);
1046
1047	return ALIGN(len, L1_CACHE_BYTES);
1048}
1049
1050static int add_recvbuf_mergeable(struct virtnet_info *vi,
1051				 struct receive_queue *rq, gfp_t gfp)
1052{
1053	struct page_frag *alloc_frag = &rq->alloc_frag;
1054	unsigned int headroom = virtnet_get_headroom(vi);
1055	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1056	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1057	char *buf;
1058	void *ctx;
1059	int err;
1060	unsigned int len, hole;
1061
1062	/* Extra tailroom is needed to satisfy XDP's assumption. This
1063	 * means rx frags coalescing won't work, but consider we've
1064	 * disabled GSO for XDP, it won't be a big issue.
1065	 */
1066	len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1067	if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1068		return -ENOMEM;
1069
1070	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1071	buf += headroom; /* advance address leaving hole at front of pkt */
1072	get_page(alloc_frag->page);
1073	alloc_frag->offset += len + room;
1074	hole = alloc_frag->size - alloc_frag->offset;
1075	if (hole < len + room) {
1076		/* To avoid internal fragmentation, if there is very likely not
1077		 * enough space for another buffer, add the remaining space to
1078		 * the current buffer.
1079		 */
1080		len += hole;
1081		alloc_frag->offset += hole;
1082	}
1083
1084	sg_init_one(rq->sg, buf, len);
1085	ctx = mergeable_len_to_ctx(len, headroom);
1086	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1087	if (err < 0)
1088		put_page(virt_to_head_page(buf));
1089
1090	return err;
1091}
1092
1093/*
1094 * Returns false if we couldn't fill entirely (OOM).
1095 *
1096 * Normally run in the receive path, but can also be run from ndo_open
1097 * before we're receiving packets, or from refill_work which is
1098 * careful to disable receiving (using napi_disable).
1099 */
1100static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1101			  gfp_t gfp)
1102{
1103	int err;
1104	bool oom;
1105
1106	do {
1107		if (vi->mergeable_rx_bufs)
1108			err = add_recvbuf_mergeable(vi, rq, gfp);
1109		else if (vi->big_packets)
1110			err = add_recvbuf_big(vi, rq, gfp);
1111		else
1112			err = add_recvbuf_small(vi, rq, gfp);
1113
1114		oom = err == -ENOMEM;
1115		if (err)
1116			break;
1117	} while (rq->vq->num_free);
1118	virtqueue_kick(rq->vq);
 
 
 
 
 
 
 
1119	return !oom;
1120}
1121
1122static void skb_recv_done(struct virtqueue *rvq)
1123{
1124	struct virtnet_info *vi = rvq->vdev->priv;
1125	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1126
1127	virtqueue_napi_schedule(&rq->napi, rvq);
1128}
1129
1130static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1131{
1132	napi_enable(napi);
1133
1134	/* If all buffers were filled by other side before we napi_enabled, we
1135	 * won't get another interrupt, so process any outstanding packets now.
1136	 * Call local_bh_enable after to trigger softIRQ processing.
1137	 */
1138	local_bh_disable();
1139	virtqueue_napi_schedule(napi, vq);
1140	local_bh_enable();
1141}
1142
1143static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1144				   struct virtqueue *vq,
1145				   struct napi_struct *napi)
1146{
1147	if (!napi->weight)
1148		return;
1149
1150	/* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1151	 * enable the feature if this is likely affine with the transmit path.
1152	 */
1153	if (!vi->affinity_hint_set) {
1154		napi->weight = 0;
1155		return;
1156	}
1157
1158	return virtnet_napi_enable(vq, napi);
1159}
1160
1161static void virtnet_napi_tx_disable(struct napi_struct *napi)
1162{
1163	if (napi->weight)
1164		napi_disable(napi);
1165}
1166
1167static void refill_work(struct work_struct *work)
1168{
1169	struct virtnet_info *vi =
1170		container_of(work, struct virtnet_info, refill.work);
1171	bool still_empty;
1172	int i;
1173
1174	for (i = 0; i < vi->curr_queue_pairs; i++) {
1175		struct receive_queue *rq = &vi->rq[i];
1176
1177		napi_disable(&rq->napi);
1178		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1179		virtnet_napi_enable(rq->vq, &rq->napi);
1180
1181		/* In theory, this can happen: if we don't get any buffers in
1182		 * we will *never* try to fill again.
1183		 */
1184		if (still_empty)
1185			schedule_delayed_work(&vi->refill, HZ/2);
1186	}
1187}
1188
1189static int virtnet_receive(struct receive_queue *rq, int budget, bool *xdp_xmit)
 
1190{
1191	struct virtnet_info *vi = rq->vq->vdev->priv;
1192	unsigned int len, received = 0, bytes = 0;
 
1193	void *buf;
 
1194
1195	if (!vi->big_packets || vi->mergeable_rx_bufs) {
1196		void *ctx;
1197
1198		while (received < budget &&
1199		       (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1200			bytes += receive_buf(vi, rq, buf, len, ctx, xdp_xmit);
1201			received++;
1202		}
1203	} else {
1204		while (received < budget &&
1205		       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1206			bytes += receive_buf(vi, rq, buf, len, NULL, xdp_xmit);
1207			received++;
1208		}
1209	}
1210
1211	if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
1212		if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1213			schedule_delayed_work(&vi->refill, 0);
 
 
 
 
1214	}
1215
1216	u64_stats_update_begin(&rq->stats.syncp);
1217	rq->stats.bytes += bytes;
1218	rq->stats.packets += received;
 
 
 
 
 
1219	u64_stats_update_end(&rq->stats.syncp);
1220
1221	return received;
1222}
1223
1224static void free_old_xmit_skbs(struct send_queue *sq)
1225{
1226	struct sk_buff *skb;
1227	unsigned int len;
1228	unsigned int packets = 0;
1229	unsigned int bytes = 0;
 
1230
1231	while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1232		pr_debug("Sent skb %p\n", skb);
 
1233
1234		bytes += skb->len;
1235		packets++;
1236
1237		dev_consume_skb_any(skb);
 
 
 
 
 
 
 
 
1238	}
1239
1240	/* Avoid overhead when no packets have been processed
1241	 * happens when called speculatively from start_xmit.
1242	 */
1243	if (!packets)
1244		return;
1245
1246	u64_stats_update_begin(&sq->stats.syncp);
1247	sq->stats.bytes += bytes;
1248	sq->stats.packets += packets;
1249	u64_stats_update_end(&sq->stats.syncp);
1250}
1251
 
 
 
 
 
 
 
 
 
 
1252static void virtnet_poll_cleantx(struct receive_queue *rq)
1253{
1254	struct virtnet_info *vi = rq->vq->vdev->priv;
1255	unsigned int index = vq2rxq(rq->vq);
1256	struct send_queue *sq = &vi->sq[index];
1257	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1258
1259	if (!sq->napi.weight)
1260		return;
1261
1262	if (__netif_tx_trylock(txq)) {
1263		free_old_xmit_skbs(sq);
 
 
 
 
 
 
 
 
 
 
 
 
1264		__netif_tx_unlock(txq);
1265	}
1266
1267	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1268		netif_tx_wake_queue(txq);
1269}
1270
1271static int virtnet_poll(struct napi_struct *napi, int budget)
1272{
1273	struct receive_queue *rq =
1274		container_of(napi, struct receive_queue, napi);
1275	struct virtnet_info *vi = rq->vq->vdev->priv;
1276	struct send_queue *sq;
1277	unsigned int received, qp;
1278	bool xdp_xmit = false;
1279
1280	virtnet_poll_cleantx(rq);
1281
1282	received = virtnet_receive(rq, budget, &xdp_xmit);
1283
 
 
 
1284	/* Out of packets? */
1285	if (received < budget)
1286		virtqueue_napi_complete(napi, rq->vq, received);
1287
1288	if (xdp_xmit) {
1289		qp = vi->curr_queue_pairs - vi->xdp_queue_pairs +
1290		     smp_processor_id();
1291		sq = &vi->sq[qp];
1292		virtqueue_kick(sq->vq);
1293		xdp_do_flush_map();
 
 
1294	}
1295
1296	return received;
1297}
1298
1299static int virtnet_open(struct net_device *dev)
1300{
1301	struct virtnet_info *vi = netdev_priv(dev);
1302	int i, err;
1303
 
 
1304	for (i = 0; i < vi->max_queue_pairs; i++) {
1305		if (i < vi->curr_queue_pairs)
1306			/* Make sure we have some buffers: if oom use wq. */
1307			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1308				schedule_delayed_work(&vi->refill, 0);
1309
1310		err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);
1311		if (err < 0)
1312			return err;
1313
 
 
 
 
 
 
 
1314		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1315		virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1316	}
1317
1318	return 0;
1319}
1320
1321static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1322{
1323	struct send_queue *sq = container_of(napi, struct send_queue, napi);
1324	struct virtnet_info *vi = sq->vq->vdev->priv;
1325	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
 
 
 
1326
1327	__netif_tx_lock(txq, raw_smp_processor_id());
1328	free_old_xmit_skbs(sq);
1329	__netif_tx_unlock(txq);
 
 
1330
1331	virtqueue_napi_complete(napi, sq->vq, 0);
 
 
 
1332
1333	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1334		netif_tx_wake_queue(txq);
1335
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1336	return 0;
1337}
1338
1339static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1340{
1341	struct virtio_net_hdr_mrg_rxbuf *hdr;
1342	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1343	struct virtnet_info *vi = sq->vq->vdev->priv;
1344	int num_sg;
1345	unsigned hdr_len = vi->hdr_len;
1346	bool can_push;
1347
1348	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1349
1350	can_push = vi->any_header_sg &&
1351		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1352		!skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1353	/* Even if we can, don't push here yet as this would skew
1354	 * csum_start offset below. */
1355	if (can_push)
1356		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1357	else
1358		hdr = skb_vnet_hdr(skb);
1359
1360	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1361				    virtio_is_little_endian(vi->vdev), false))
1362		BUG();
 
1363
1364	if (vi->mergeable_rx_bufs)
1365		hdr->num_buffers = 0;
1366
1367	sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1368	if (can_push) {
1369		__skb_push(skb, hdr_len);
1370		num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1371		if (unlikely(num_sg < 0))
1372			return num_sg;
1373		/* Pull header back to avoid skew in tx bytes calculations. */
1374		__skb_pull(skb, hdr_len);
1375	} else {
1376		sg_set_buf(sq->sg, hdr, hdr_len);
1377		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1378		if (unlikely(num_sg < 0))
1379			return num_sg;
1380		num_sg++;
1381	}
1382	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1383}
1384
1385static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1386{
1387	struct virtnet_info *vi = netdev_priv(dev);
1388	int qnum = skb_get_queue_mapping(skb);
1389	struct send_queue *sq = &vi->sq[qnum];
1390	int err;
1391	struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1392	bool kick = !skb->xmit_more;
1393	bool use_napi = sq->napi.weight;
1394
1395	/* Free up any pending old buffers before queueing new ones. */
1396	free_old_xmit_skbs(sq);
 
 
 
 
1397
1398	if (use_napi && kick)
1399		virtqueue_enable_cb_delayed(sq->vq);
1400
1401	/* timestamp packet in software */
1402	skb_tx_timestamp(skb);
1403
1404	/* Try to transmit */
1405	err = xmit_skb(sq, skb);
1406
1407	/* This should not happen! */
1408	if (unlikely(err)) {
1409		dev->stats.tx_fifo_errors++;
1410		if (net_ratelimit())
1411			dev_warn(&dev->dev,
1412				 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 
1413		dev->stats.tx_dropped++;
1414		dev_kfree_skb_any(skb);
1415		return NETDEV_TX_OK;
1416	}
1417
1418	/* Don't wait up for transmitted skbs to be freed. */
1419	if (!use_napi) {
1420		skb_orphan(skb);
1421		nf_reset(skb);
1422	}
1423
1424	/* If running out of space, stop queue to avoid getting packets that we
1425	 * are then unable to transmit.
1426	 * An alternative would be to force queuing layer to requeue the skb by
1427	 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1428	 * returned in a normal path of operation: it means that driver is not
1429	 * maintaining the TX queue stop/start state properly, and causes
1430	 * the stack to do a non-trivial amount of useless work.
1431	 * Since most packets only take 1 or 2 ring slots, stopping the queue
1432	 * early means 16 slots are typically wasted.
1433	 */
1434	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1435		netif_stop_subqueue(dev, qnum);
1436		if (!use_napi &&
1437		    unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 
 
1438			/* More just got used, free them then recheck. */
1439			free_old_xmit_skbs(sq);
1440			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1441				netif_start_subqueue(dev, qnum);
1442				virtqueue_disable_cb(sq->vq);
1443			}
1444		}
1445	}
1446
1447	if (kick || netif_xmit_stopped(txq))
1448		virtqueue_kick(sq->vq);
 
 
 
 
 
1449
1450	return NETDEV_TX_OK;
1451}
1452
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1453/*
1454 * Send command via the control virtqueue and check status.  Commands
1455 * supported by the hypervisor, as indicated by feature bits, should
1456 * never fail unless improperly formatted.
1457 */
1458static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1459				 struct scatterlist *out)
1460{
1461	struct scatterlist *sgs[4], hdr, stat;
1462	unsigned out_num = 0, tmp;
 
1463
1464	/* Caller should know better */
1465	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1466
1467	vi->ctrl->status = ~0;
1468	vi->ctrl->hdr.class = class;
1469	vi->ctrl->hdr.cmd = cmd;
1470	/* Add header */
1471	sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1472	sgs[out_num++] = &hdr;
1473
1474	if (out)
1475		sgs[out_num++] = out;
1476
1477	/* Add return status. */
1478	sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1479	sgs[out_num] = &stat;
1480
1481	BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1482	virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 
 
 
 
 
1483
1484	if (unlikely(!virtqueue_kick(vi->cvq)))
1485		return vi->ctrl->status == VIRTIO_NET_OK;
1486
1487	/* Spin for a response, the kick causes an ioport write, trapping
1488	 * into the hypervisor, so the request should be handled immediately.
1489	 */
1490	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1491	       !virtqueue_is_broken(vi->cvq))
1492		cpu_relax();
1493
1494	return vi->ctrl->status == VIRTIO_NET_OK;
1495}
1496
1497static int virtnet_set_mac_address(struct net_device *dev, void *p)
1498{
1499	struct virtnet_info *vi = netdev_priv(dev);
1500	struct virtio_device *vdev = vi->vdev;
1501	int ret;
1502	struct sockaddr *addr;
1503	struct scatterlist sg;
1504
 
 
 
1505	addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1506	if (!addr)
1507		return -ENOMEM;
1508
1509	ret = eth_prepare_mac_addr_change(dev, addr);
1510	if (ret)
1511		goto out;
1512
1513	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1514		sg_init_one(&sg, addr->sa_data, dev->addr_len);
1515		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1516					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1517			dev_warn(&vdev->dev,
1518				 "Failed to set mac address by vq command.\n");
1519			ret = -EINVAL;
1520			goto out;
1521		}
1522	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1523		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1524		unsigned int i;
1525
1526		/* Naturally, this has an atomicity problem. */
1527		for (i = 0; i < dev->addr_len; i++)
1528			virtio_cwrite8(vdev,
1529				       offsetof(struct virtio_net_config, mac) +
1530				       i, addr->sa_data[i]);
1531	}
1532
1533	eth_commit_mac_addr_change(dev, p);
1534	ret = 0;
1535
1536out:
1537	kfree(addr);
1538	return ret;
1539}
1540
1541static void virtnet_stats(struct net_device *dev,
1542			  struct rtnl_link_stats64 *tot)
1543{
1544	struct virtnet_info *vi = netdev_priv(dev);
1545	unsigned int start;
1546	int i;
1547
1548	for (i = 0; i < vi->max_queue_pairs; i++) {
1549		u64 tpackets, tbytes, rpackets, rbytes;
1550		struct receive_queue *rq = &vi->rq[i];
1551		struct send_queue *sq = &vi->sq[i];
1552
1553		do {
1554			start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1555			tpackets = sq->stats.packets;
1556			tbytes   = sq->stats.bytes;
1557		} while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
 
1558
1559		do {
1560			start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1561			rpackets = rq->stats.packets;
1562			rbytes   = rq->stats.bytes;
1563		} while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
 
1564
1565		tot->rx_packets += rpackets;
1566		tot->tx_packets += tpackets;
1567		tot->rx_bytes   += rbytes;
1568		tot->tx_bytes   += tbytes;
 
 
1569	}
1570
1571	tot->tx_dropped = dev->stats.tx_dropped;
1572	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1573	tot->rx_dropped = dev->stats.rx_dropped;
1574	tot->rx_length_errors = dev->stats.rx_length_errors;
1575	tot->rx_frame_errors = dev->stats.rx_frame_errors;
1576}
1577
1578#ifdef CONFIG_NET_POLL_CONTROLLER
1579static void virtnet_netpoll(struct net_device *dev)
1580{
1581	struct virtnet_info *vi = netdev_priv(dev);
1582	int i;
1583
1584	for (i = 0; i < vi->curr_queue_pairs; i++)
1585		napi_schedule(&vi->rq[i].napi);
1586}
1587#endif
1588
1589static void virtnet_ack_link_announce(struct virtnet_info *vi)
1590{
1591	rtnl_lock();
1592	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1593				  VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1594		dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1595	rtnl_unlock();
1596}
1597
1598static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1599{
1600	struct scatterlist sg;
1601	struct net_device *dev = vi->dev;
1602
1603	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1604		return 0;
1605
1606	vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1607	sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1608
1609	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1610				  VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1611		dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1612			 queue_pairs);
1613		return -EINVAL;
1614	} else {
1615		vi->curr_queue_pairs = queue_pairs;
1616		/* virtnet_open() will refill when device is going to up. */
1617		if (dev->flags & IFF_UP)
1618			schedule_delayed_work(&vi->refill, 0);
1619	}
1620
1621	return 0;
1622}
1623
1624static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1625{
1626	int err;
1627
1628	rtnl_lock();
1629	err = _virtnet_set_queues(vi, queue_pairs);
1630	rtnl_unlock();
1631	return err;
1632}
1633
1634static int virtnet_close(struct net_device *dev)
1635{
1636	struct virtnet_info *vi = netdev_priv(dev);
1637	int i;
1638
 
 
1639	/* Make sure refill_work doesn't re-enable napi! */
1640	cancel_delayed_work_sync(&vi->refill);
1641
1642	for (i = 0; i < vi->max_queue_pairs; i++) {
1643		xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1644		napi_disable(&vi->rq[i].napi);
 
1645		virtnet_napi_tx_disable(&vi->sq[i].napi);
1646	}
1647
1648	return 0;
1649}
1650
1651static void virtnet_set_rx_mode(struct net_device *dev)
1652{
1653	struct virtnet_info *vi = netdev_priv(dev);
1654	struct scatterlist sg[2];
1655	struct virtio_net_ctrl_mac *mac_data;
1656	struct netdev_hw_addr *ha;
1657	int uc_count;
1658	int mc_count;
1659	void *buf;
1660	int i;
1661
1662	/* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1663	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1664		return;
1665
1666	vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1667	vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1668
1669	sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1670
1671	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1672				  VIRTIO_NET_CTRL_RX_PROMISC, sg))
1673		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1674			 vi->ctrl->promisc ? "en" : "dis");
1675
1676	sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1677
1678	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1679				  VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1680		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1681			 vi->ctrl->allmulti ? "en" : "dis");
1682
1683	uc_count = netdev_uc_count(dev);
1684	mc_count = netdev_mc_count(dev);
1685	/* MAC filter - use one buffer for both lists */
1686	buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1687		      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1688	mac_data = buf;
1689	if (!buf)
1690		return;
1691
1692	sg_init_table(sg, 2);
1693
1694	/* Store the unicast list and count in the front of the buffer */
1695	mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1696	i = 0;
1697	netdev_for_each_uc_addr(ha, dev)
1698		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1699
1700	sg_set_buf(&sg[0], mac_data,
1701		   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1702
1703	/* multicast list and count fill the end */
1704	mac_data = (void *)&mac_data->macs[uc_count][0];
1705
1706	mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1707	i = 0;
1708	netdev_for_each_mc_addr(ha, dev)
1709		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1710
1711	sg_set_buf(&sg[1], mac_data,
1712		   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1713
1714	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1715				  VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1716		dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1717
1718	kfree(buf);
1719}
1720
1721static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1722				   __be16 proto, u16 vid)
1723{
1724	struct virtnet_info *vi = netdev_priv(dev);
1725	struct scatterlist sg;
1726
1727	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1728	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1729
1730	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1731				  VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1732		dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1733	return 0;
1734}
1735
1736static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1737				    __be16 proto, u16 vid)
1738{
1739	struct virtnet_info *vi = netdev_priv(dev);
1740	struct scatterlist sg;
1741
1742	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1743	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1744
1745	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1746				  VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1747		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1748	return 0;
1749}
1750
1751static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1752{
1753	int i;
1754
1755	if (vi->affinity_hint_set) {
1756		for (i = 0; i < vi->max_queue_pairs; i++) {
1757			virtqueue_set_affinity(vi->rq[i].vq, -1);
1758			virtqueue_set_affinity(vi->sq[i].vq, -1);
1759		}
1760
1761		vi->affinity_hint_set = false;
1762	}
1763}
1764
1765static void virtnet_set_affinity(struct virtnet_info *vi)
1766{
1767	int i;
1768	int cpu;
 
 
 
 
1769
1770	/* In multiqueue mode, when the number of cpu is equal to the number of
1771	 * queue pairs, we let the queue pairs to be private to one cpu by
1772	 * setting the affinity hint to eliminate the contention.
1773	 */
1774	if (vi->curr_queue_pairs == 1 ||
1775	    vi->max_queue_pairs != num_online_cpus()) {
1776		virtnet_clean_affinity(vi, -1);
1777		return;
1778	}
1779
1780	i = 0;
1781	for_each_online_cpu(cpu) {
1782		virtqueue_set_affinity(vi->rq[i].vq, cpu);
1783		virtqueue_set_affinity(vi->sq[i].vq, cpu);
1784		netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1785		i++;
 
 
 
 
 
 
 
 
 
 
 
 
 
1786	}
1787
1788	vi->affinity_hint_set = true;
 
1789}
1790
1791static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1792{
1793	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1794						   node);
1795	virtnet_set_affinity(vi);
1796	return 0;
1797}
1798
1799static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1800{
1801	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1802						   node_dead);
1803	virtnet_set_affinity(vi);
1804	return 0;
1805}
1806
1807static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1808{
1809	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1810						   node);
1811
1812	virtnet_clean_affinity(vi, cpu);
1813	return 0;
1814}
1815
1816static enum cpuhp_state virtionet_online;
1817
1818static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1819{
1820	int ret;
1821
1822	ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1823	if (ret)
1824		return ret;
1825	ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1826					       &vi->node_dead);
1827	if (!ret)
1828		return ret;
1829	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1830	return ret;
1831}
1832
1833static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1834{
1835	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1836	cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1837					    &vi->node_dead);
1838}
1839
1840static void virtnet_get_ringparam(struct net_device *dev,
1841				struct ethtool_ringparam *ring)
 
 
1842{
1843	struct virtnet_info *vi = netdev_priv(dev);
1844
1845	ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1846	ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1847	ring->rx_pending = ring->rx_max_pending;
1848	ring->tx_pending = ring->tx_max_pending;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1849}
1850
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1851
1852static void virtnet_get_drvinfo(struct net_device *dev,
1853				struct ethtool_drvinfo *info)
1854{
1855	struct virtnet_info *vi = netdev_priv(dev);
1856	struct virtio_device *vdev = vi->vdev;
1857
1858	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1859	strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1860	strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1861
1862}
1863
1864/* TODO: Eliminate OOO packets during switching */
1865static int virtnet_set_channels(struct net_device *dev,
1866				struct ethtool_channels *channels)
1867{
1868	struct virtnet_info *vi = netdev_priv(dev);
1869	u16 queue_pairs = channels->combined_count;
1870	int err;
1871
1872	/* We don't support separate rx/tx channels.
1873	 * We don't allow setting 'other' channels.
1874	 */
1875	if (channels->rx_count || channels->tx_count || channels->other_count)
1876		return -EINVAL;
1877
1878	if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1879		return -EINVAL;
1880
1881	/* For now we don't support modifying channels while XDP is loaded
1882	 * also when XDP is loaded all RX queues have XDP programs so we only
1883	 * need to check a single RX queue.
1884	 */
1885	if (vi->rq[0].xdp_prog)
1886		return -EINVAL;
1887
1888	get_online_cpus();
1889	err = _virtnet_set_queues(vi, queue_pairs);
1890	if (!err) {
1891		netif_set_real_num_tx_queues(dev, queue_pairs);
1892		netif_set_real_num_rx_queues(dev, queue_pairs);
1893
1894		virtnet_set_affinity(vi);
1895	}
1896	put_online_cpus();
 
1897
 
 
 
1898	return err;
1899}
1900
1901static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1902{
1903	struct virtnet_info *vi = netdev_priv(dev);
1904	char *p = (char *)data;
1905	unsigned int i, j;
 
1906
1907	switch (stringset) {
1908	case ETH_SS_STATS:
1909		for (i = 0; i < vi->curr_queue_pairs; i++) {
1910			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
1911				snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
1912					 i, virtnet_rq_stats_desc[j].desc);
1913				p += ETH_GSTRING_LEN;
1914			}
1915		}
1916
1917		for (i = 0; i < vi->curr_queue_pairs; i++) {
1918			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
1919				snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
1920					 i, virtnet_sq_stats_desc[j].desc);
1921				p += ETH_GSTRING_LEN;
1922			}
1923		}
1924		break;
1925	}
1926}
1927
1928static int virtnet_get_sset_count(struct net_device *dev, int sset)
1929{
1930	struct virtnet_info *vi = netdev_priv(dev);
1931
1932	switch (sset) {
1933	case ETH_SS_STATS:
1934		return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
1935					       VIRTNET_SQ_STATS_LEN);
1936	default:
1937		return -EOPNOTSUPP;
1938	}
1939}
1940
1941static void virtnet_get_ethtool_stats(struct net_device *dev,
1942				      struct ethtool_stats *stats, u64 *data)
1943{
1944	struct virtnet_info *vi = netdev_priv(dev);
1945	unsigned int idx = 0, start, i, j;
1946	const u8 *stats_base;
1947	size_t offset;
1948
1949	for (i = 0; i < vi->curr_queue_pairs; i++) {
1950		struct receive_queue *rq = &vi->rq[i];
1951
1952		stats_base = (u8 *)&rq->stats;
1953		do {
1954			start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1955			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
1956				offset = virtnet_rq_stats_desc[j].offset;
1957				data[idx + j] = *(u64 *)(stats_base + offset);
1958			}
1959		} while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1960		idx += VIRTNET_RQ_STATS_LEN;
1961	}
1962
1963	for (i = 0; i < vi->curr_queue_pairs; i++) {
1964		struct send_queue *sq = &vi->sq[i];
1965
1966		stats_base = (u8 *)&sq->stats;
1967		do {
1968			start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1969			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
1970				offset = virtnet_sq_stats_desc[j].offset;
1971				data[idx + j] = *(u64 *)(stats_base + offset);
1972			}
1973		} while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1974		idx += VIRTNET_SQ_STATS_LEN;
1975	}
1976}
1977
1978static void virtnet_get_channels(struct net_device *dev,
1979				 struct ethtool_channels *channels)
1980{
1981	struct virtnet_info *vi = netdev_priv(dev);
1982
1983	channels->combined_count = vi->curr_queue_pairs;
1984	channels->max_combined = vi->max_queue_pairs;
1985	channels->max_other = 0;
1986	channels->rx_count = 0;
1987	channels->tx_count = 0;
1988	channels->other_count = 0;
1989}
1990
1991/* Check if the user is trying to change anything besides speed/duplex */
1992static bool
1993virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
1994{
1995	struct ethtool_link_ksettings diff1 = *cmd;
1996	struct ethtool_link_ksettings diff2 = {};
1997
1998	/* cmd is always set so we need to clear it, validate the port type
1999	 * and also without autonegotiation we can ignore advertising
2000	 */
2001	diff1.base.speed = 0;
2002	diff2.base.port = PORT_OTHER;
2003	ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
2004	diff1.base.duplex = 0;
2005	diff1.base.cmd = 0;
2006	diff1.base.link_mode_masks_nwords = 0;
2007
2008	return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
2009		bitmap_empty(diff1.link_modes.supported,
2010			     __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2011		bitmap_empty(diff1.link_modes.advertising,
2012			     __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2013		bitmap_empty(diff1.link_modes.lp_advertising,
2014			     __ETHTOOL_LINK_MODE_MASK_NBITS);
2015}
2016
2017static int virtnet_set_link_ksettings(struct net_device *dev,
2018				      const struct ethtool_link_ksettings *cmd)
2019{
2020	struct virtnet_info *vi = netdev_priv(dev);
2021	u32 speed;
2022
2023	speed = cmd->base.speed;
2024	/* don't allow custom speed and duplex */
2025	if (!ethtool_validate_speed(speed) ||
2026	    !ethtool_validate_duplex(cmd->base.duplex) ||
2027	    !virtnet_validate_ethtool_cmd(cmd))
2028		return -EINVAL;
2029	vi->speed = speed;
2030	vi->duplex = cmd->base.duplex;
2031
2032	return 0;
 
2033}
2034
2035static int virtnet_get_link_ksettings(struct net_device *dev,
2036				      struct ethtool_link_ksettings *cmd)
2037{
2038	struct virtnet_info *vi = netdev_priv(dev);
2039
2040	cmd->base.speed = vi->speed;
2041	cmd->base.duplex = vi->duplex;
2042	cmd->base.port = PORT_OTHER;
2043
2044	return 0;
2045}
2046
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2047static void virtnet_init_settings(struct net_device *dev)
2048{
2049	struct virtnet_info *vi = netdev_priv(dev);
2050
2051	vi->speed = SPEED_UNKNOWN;
2052	vi->duplex = DUPLEX_UNKNOWN;
2053}
2054
2055static void virtnet_update_settings(struct virtnet_info *vi)
2056{
2057	u32 speed;
2058	u8 duplex;
2059
2060	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2061		return;
2062
2063	speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
2064						  speed));
2065	if (ethtool_validate_speed(speed))
2066		vi->speed = speed;
2067	duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
2068						  duplex));
 
2069	if (ethtool_validate_duplex(duplex))
2070		vi->duplex = duplex;
2071}
2072
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2073static const struct ethtool_ops virtnet_ethtool_ops = {
 
 
2074	.get_drvinfo = virtnet_get_drvinfo,
2075	.get_link = ethtool_op_get_link,
2076	.get_ringparam = virtnet_get_ringparam,
 
2077	.get_strings = virtnet_get_strings,
2078	.get_sset_count = virtnet_get_sset_count,
2079	.get_ethtool_stats = virtnet_get_ethtool_stats,
2080	.set_channels = virtnet_set_channels,
2081	.get_channels = virtnet_get_channels,
2082	.get_ts_info = ethtool_op_get_ts_info,
2083	.get_link_ksettings = virtnet_get_link_ksettings,
2084	.set_link_ksettings = virtnet_set_link_ksettings,
 
 
 
 
 
 
 
 
2085};
2086
2087static void virtnet_freeze_down(struct virtio_device *vdev)
2088{
2089	struct virtnet_info *vi = vdev->priv;
2090	int i;
2091
2092	/* Make sure no work handler is accessing the device */
2093	flush_work(&vi->config_work);
2094
 
2095	netif_device_detach(vi->dev);
2096	netif_tx_disable(vi->dev);
2097	cancel_delayed_work_sync(&vi->refill);
2098
2099	if (netif_running(vi->dev)) {
2100		for (i = 0; i < vi->max_queue_pairs; i++) {
2101			napi_disable(&vi->rq[i].napi);
2102			virtnet_napi_tx_disable(&vi->sq[i].napi);
2103		}
2104	}
2105}
2106
2107static int init_vqs(struct virtnet_info *vi);
2108
2109static int virtnet_restore_up(struct virtio_device *vdev)
2110{
2111	struct virtnet_info *vi = vdev->priv;
2112	int err, i;
2113
2114	err = init_vqs(vi);
2115	if (err)
2116		return err;
2117
2118	virtio_device_ready(vdev);
2119
2120	if (netif_running(vi->dev)) {
2121		for (i = 0; i < vi->curr_queue_pairs; i++)
2122			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2123				schedule_delayed_work(&vi->refill, 0);
2124
2125		for (i = 0; i < vi->max_queue_pairs; i++) {
2126			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2127			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2128					       &vi->sq[i].napi);
2129		}
2130	}
2131
 
2132	netif_device_attach(vi->dev);
 
2133	return err;
2134}
2135
2136static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2137{
2138	struct scatterlist sg;
2139	vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2140
2141	sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2142
2143	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2144				  VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2145		dev_warn(&vi->dev->dev, "Fail to set guest offload. \n");
2146		return -EINVAL;
2147	}
2148
2149	return 0;
2150}
2151
2152static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2153{
2154	u64 offloads = 0;
2155
2156	if (!vi->guest_offloads)
2157		return 0;
2158
2159	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
2160		offloads = 1ULL << VIRTIO_NET_F_GUEST_CSUM;
2161
2162	return virtnet_set_guest_offloads(vi, offloads);
2163}
2164
2165static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2166{
2167	u64 offloads = vi->guest_offloads;
2168
2169	if (!vi->guest_offloads)
2170		return 0;
2171	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
2172		offloads |= 1ULL << VIRTIO_NET_F_GUEST_CSUM;
2173
2174	return virtnet_set_guest_offloads(vi, offloads);
2175}
2176
2177static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2178			   struct netlink_ext_ack *extack)
2179{
2180	unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2181	struct virtnet_info *vi = netdev_priv(dev);
2182	struct bpf_prog *old_prog;
2183	u16 xdp_qp = 0, curr_qp;
2184	int i, err;
2185
2186	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2187	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2188	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2189	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2190		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO))) {
2191		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO, disable LRO first");
 
 
 
2192		return -EOPNOTSUPP;
2193	}
2194
2195	if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2196		NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2197		return -EINVAL;
2198	}
2199
2200	if (dev->mtu > max_sz) {
2201		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2202		netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2203		return -EINVAL;
2204	}
2205
2206	curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2207	if (prog)
2208		xdp_qp = nr_cpu_ids;
2209
2210	/* XDP requires extra queues for XDP_TX */
2211	if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2212		NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
2213		netdev_warn(dev, "request %i queues but max is %i\n",
2214			    curr_qp + xdp_qp, vi->max_queue_pairs);
2215		return -ENOMEM;
2216	}
2217
2218	if (prog) {
2219		prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
2220		if (IS_ERR(prog))
2221			return PTR_ERR(prog);
2222	}
 
2223
2224	/* Make sure NAPI is not using any XDP TX queues for RX. */
2225	if (netif_running(dev))
2226		for (i = 0; i < vi->max_queue_pairs; i++)
2227			napi_disable(&vi->rq[i].napi);
 
 
 
 
 
 
 
 
 
 
 
 
2228
2229	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2230	err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2231	if (err)
2232		goto err;
 
2233	vi->xdp_queue_pairs = xdp_qp;
2234
2235	for (i = 0; i < vi->max_queue_pairs; i++) {
2236		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2237		rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2238		if (i == 0) {
2239			if (!old_prog)
2240				virtnet_clear_guest_offloads(vi);
2241			if (!prog)
2242				virtnet_restore_guest_offloads(vi);
2243		}
 
 
 
 
 
2244		if (old_prog)
2245			bpf_prog_put(old_prog);
2246		if (netif_running(dev))
2247			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
 
 
 
2248	}
2249
2250	return 0;
2251
2252err:
2253	for (i = 0; i < vi->max_queue_pairs; i++)
2254		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
 
 
 
 
 
 
 
 
 
 
 
2255	if (prog)
2256		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2257	return err;
2258}
2259
2260static u32 virtnet_xdp_query(struct net_device *dev)
2261{
2262	struct virtnet_info *vi = netdev_priv(dev);
2263	const struct bpf_prog *xdp_prog;
2264	int i;
2265
2266	for (i = 0; i < vi->max_queue_pairs; i++) {
2267		xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2268		if (xdp_prog)
2269			return xdp_prog->aux->id;
2270	}
2271	return 0;
2272}
2273
2274static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2275{
2276	switch (xdp->command) {
2277	case XDP_SETUP_PROG:
2278		return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2279	case XDP_QUERY_PROG:
2280		xdp->prog_id = virtnet_xdp_query(dev);
2281		xdp->prog_attached = !!xdp->prog_id;
2282		return 0;
2283	default:
2284		return -EINVAL;
2285	}
2286}
2287
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2288static const struct net_device_ops virtnet_netdev = {
2289	.ndo_open            = virtnet_open,
2290	.ndo_stop   	     = virtnet_close,
2291	.ndo_start_xmit      = start_xmit,
2292	.ndo_validate_addr   = eth_validate_addr,
2293	.ndo_set_mac_address = virtnet_set_mac_address,
2294	.ndo_set_rx_mode     = virtnet_set_rx_mode,
2295	.ndo_get_stats64     = virtnet_stats,
2296	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2297	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2298#ifdef CONFIG_NET_POLL_CONTROLLER
2299	.ndo_poll_controller = virtnet_netpoll,
2300#endif
2301	.ndo_bpf		= virtnet_xdp,
2302	.ndo_xdp_xmit		= virtnet_xdp_xmit,
2303	.ndo_xdp_flush		= virtnet_xdp_flush,
2304	.ndo_features_check	= passthru_features_check,
 
 
 
2305};
2306
2307static void virtnet_config_changed_work(struct work_struct *work)
2308{
2309	struct virtnet_info *vi =
2310		container_of(work, struct virtnet_info, config_work);
2311	u16 v;
2312
2313	if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2314				 struct virtio_net_config, status, &v) < 0)
2315		return;
2316
2317	if (v & VIRTIO_NET_S_ANNOUNCE) {
2318		netdev_notify_peers(vi->dev);
2319		virtnet_ack_link_announce(vi);
2320	}
2321
2322	/* Ignore unknown (future) status bits */
2323	v &= VIRTIO_NET_S_LINK_UP;
2324
2325	if (vi->status == v)
2326		return;
2327
2328	vi->status = v;
2329
2330	if (vi->status & VIRTIO_NET_S_LINK_UP) {
2331		virtnet_update_settings(vi);
2332		netif_carrier_on(vi->dev);
2333		netif_tx_wake_all_queues(vi->dev);
2334	} else {
2335		netif_carrier_off(vi->dev);
2336		netif_tx_stop_all_queues(vi->dev);
2337	}
2338}
2339
2340static void virtnet_config_changed(struct virtio_device *vdev)
2341{
2342	struct virtnet_info *vi = vdev->priv;
2343
2344	schedule_work(&vi->config_work);
2345}
2346
2347static void virtnet_free_queues(struct virtnet_info *vi)
2348{
2349	int i;
2350
2351	for (i = 0; i < vi->max_queue_pairs; i++) {
2352		napi_hash_del(&vi->rq[i].napi);
2353		netif_napi_del(&vi->rq[i].napi);
2354		netif_napi_del(&vi->sq[i].napi);
2355	}
2356
2357	/* We called napi_hash_del() before netif_napi_del(),
2358	 * we need to respect an RCU grace period before freeing vi->rq
2359	 */
2360	synchronize_net();
2361
2362	kfree(vi->rq);
2363	kfree(vi->sq);
2364	kfree(vi->ctrl);
2365}
2366
2367static void _free_receive_bufs(struct virtnet_info *vi)
2368{
2369	struct bpf_prog *old_prog;
2370	int i;
2371
2372	for (i = 0; i < vi->max_queue_pairs; i++) {
2373		while (vi->rq[i].pages)
2374			__free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2375
2376		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2377		RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2378		if (old_prog)
2379			bpf_prog_put(old_prog);
2380	}
2381}
2382
2383static void free_receive_bufs(struct virtnet_info *vi)
2384{
2385	rtnl_lock();
2386	_free_receive_bufs(vi);
2387	rtnl_unlock();
2388}
2389
2390static void free_receive_page_frags(struct virtnet_info *vi)
2391{
2392	int i;
2393	for (i = 0; i < vi->max_queue_pairs; i++)
2394		if (vi->rq[i].alloc_frag.page)
2395			put_page(vi->rq[i].alloc_frag.page);
2396}
2397
2398static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
2399{
2400	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
2401		return false;
2402	else if (q < vi->curr_queue_pairs)
2403		return true;
2404	else
2405		return false;
 
 
 
 
 
 
 
 
 
 
 
 
 
2406}
2407
2408static void free_unused_bufs(struct virtnet_info *vi)
2409{
2410	void *buf;
2411	int i;
2412
2413	for (i = 0; i < vi->max_queue_pairs; i++) {
2414		struct virtqueue *vq = vi->sq[i].vq;
2415		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2416			if (!is_xdp_raw_buffer_queue(vi, i))
2417				dev_kfree_skb(buf);
2418			else
2419				put_page(virt_to_head_page(buf));
2420		}
2421	}
2422
2423	for (i = 0; i < vi->max_queue_pairs; i++) {
2424		struct virtqueue *vq = vi->rq[i].vq;
2425
2426		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2427			if (vi->mergeable_rx_bufs) {
2428				put_page(virt_to_head_page(buf));
2429			} else if (vi->big_packets) {
2430				give_pages(&vi->rq[i], buf);
2431			} else {
2432				put_page(virt_to_head_page(buf));
2433			}
2434		}
2435	}
2436}
2437
2438static void virtnet_del_vqs(struct virtnet_info *vi)
2439{
2440	struct virtio_device *vdev = vi->vdev;
2441
2442	virtnet_clean_affinity(vi, -1);
2443
2444	vdev->config->del_vqs(vdev);
2445
2446	virtnet_free_queues(vi);
2447}
2448
2449/* How large should a single buffer be so a queue full of these can fit at
2450 * least one full packet?
2451 * Logic below assumes the mergeable buffer header is used.
2452 */
2453static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2454{
2455	const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2456	unsigned int rq_size = virtqueue_get_vring_size(vq);
2457	unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2458	unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2459	unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2460
2461	return max(max(min_buf_len, hdr_len) - hdr_len,
2462		   (unsigned int)GOOD_PACKET_LEN);
2463}
2464
2465static int virtnet_find_vqs(struct virtnet_info *vi)
2466{
2467	vq_callback_t **callbacks;
2468	struct virtqueue **vqs;
2469	int ret = -ENOMEM;
2470	int i, total_vqs;
2471	const char **names;
2472	bool *ctx;
2473
2474	/* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2475	 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2476	 * possible control vq.
2477	 */
2478	total_vqs = vi->max_queue_pairs * 2 +
2479		    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2480
2481	/* Allocate space for find_vqs parameters */
2482	vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
2483	if (!vqs)
2484		goto err_vq;
2485	callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
2486	if (!callbacks)
2487		goto err_callback;
2488	names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
2489	if (!names)
2490		goto err_names;
2491	if (!vi->big_packets || vi->mergeable_rx_bufs) {
2492		ctx = kzalloc(total_vqs * sizeof(*ctx), GFP_KERNEL);
2493		if (!ctx)
2494			goto err_ctx;
2495	} else {
2496		ctx = NULL;
2497	}
2498
2499	/* Parameters for control virtqueue, if any */
2500	if (vi->has_cvq) {
2501		callbacks[total_vqs - 1] = NULL;
2502		names[total_vqs - 1] = "control";
2503	}
2504
2505	/* Allocate/initialize parameters for send/receive virtqueues */
2506	for (i = 0; i < vi->max_queue_pairs; i++) {
2507		callbacks[rxq2vq(i)] = skb_recv_done;
2508		callbacks[txq2vq(i)] = skb_xmit_done;
2509		sprintf(vi->rq[i].name, "input.%d", i);
2510		sprintf(vi->sq[i].name, "output.%d", i);
2511		names[rxq2vq(i)] = vi->rq[i].name;
2512		names[txq2vq(i)] = vi->sq[i].name;
2513		if (ctx)
2514			ctx[rxq2vq(i)] = true;
2515	}
2516
2517	ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2518					 names, ctx, NULL);
2519	if (ret)
2520		goto err_find;
2521
2522	if (vi->has_cvq) {
2523		vi->cvq = vqs[total_vqs - 1];
2524		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2525			vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2526	}
2527
2528	for (i = 0; i < vi->max_queue_pairs; i++) {
2529		vi->rq[i].vq = vqs[rxq2vq(i)];
2530		vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2531		vi->sq[i].vq = vqs[txq2vq(i)];
2532	}
2533
2534	kfree(names);
2535	kfree(callbacks);
2536	kfree(vqs);
2537	kfree(ctx);
2538
2539	return 0;
2540
2541err_find:
2542	kfree(ctx);
2543err_ctx:
2544	kfree(names);
2545err_names:
2546	kfree(callbacks);
2547err_callback:
2548	kfree(vqs);
2549err_vq:
2550	return ret;
2551}
2552
2553static int virtnet_alloc_queues(struct virtnet_info *vi)
2554{
2555	int i;
2556
2557	vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2558	if (!vi->ctrl)
2559		goto err_ctrl;
2560	vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
 
 
 
 
2561	if (!vi->sq)
2562		goto err_sq;
2563	vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
2564	if (!vi->rq)
2565		goto err_rq;
2566
2567	INIT_DELAYED_WORK(&vi->refill, refill_work);
2568	for (i = 0; i < vi->max_queue_pairs; i++) {
2569		vi->rq[i].pages = NULL;
2570		netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2571			       napi_weight);
2572		netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2573				  napi_tx ? napi_weight : 0);
 
2574
2575		sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2576		ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2577		sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2578
2579		u64_stats_init(&vi->rq[i].stats.syncp);
2580		u64_stats_init(&vi->sq[i].stats.syncp);
2581	}
2582
2583	return 0;
2584
2585err_rq:
2586	kfree(vi->sq);
2587err_sq:
2588	kfree(vi->ctrl);
2589err_ctrl:
2590	return -ENOMEM;
2591}
2592
2593static int init_vqs(struct virtnet_info *vi)
2594{
2595	int ret;
2596
2597	/* Allocate send & receive queues */
2598	ret = virtnet_alloc_queues(vi);
2599	if (ret)
2600		goto err;
2601
2602	ret = virtnet_find_vqs(vi);
2603	if (ret)
2604		goto err_free;
2605
2606	get_online_cpus();
2607	virtnet_set_affinity(vi);
2608	put_online_cpus();
2609
2610	return 0;
2611
2612err_free:
2613	virtnet_free_queues(vi);
2614err:
2615	return ret;
2616}
2617
2618#ifdef CONFIG_SYSFS
2619static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2620		char *buf)
2621{
2622	struct virtnet_info *vi = netdev_priv(queue->dev);
2623	unsigned int queue_index = get_netdev_rx_queue_index(queue);
2624	unsigned int headroom = virtnet_get_headroom(vi);
2625	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2626	struct ewma_pkt_len *avg;
2627
2628	BUG_ON(queue_index >= vi->max_queue_pairs);
2629	avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2630	return sprintf(buf, "%u\n",
2631		       get_mergeable_buf_len(&vi->rq[queue_index], avg,
2632				       SKB_DATA_ALIGN(headroom + tailroom)));
2633}
2634
2635static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2636	__ATTR_RO(mergeable_rx_buffer_size);
2637
2638static struct attribute *virtio_net_mrg_rx_attrs[] = {
2639	&mergeable_rx_buffer_size_attribute.attr,
2640	NULL
2641};
2642
2643static const struct attribute_group virtio_net_mrg_rx_group = {
2644	.name = "virtio_net",
2645	.attrs = virtio_net_mrg_rx_attrs
2646};
2647#endif
2648
2649static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2650				    unsigned int fbit,
2651				    const char *fname, const char *dname)
2652{
2653	if (!virtio_has_feature(vdev, fbit))
2654		return false;
2655
2656	dev_err(&vdev->dev, "device advertises feature %s but not %s",
2657		fname, dname);
2658
2659	return true;
2660}
2661
2662#define VIRTNET_FAIL_ON(vdev, fbit, dbit)			\
2663	virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2664
2665static bool virtnet_validate_features(struct virtio_device *vdev)
2666{
2667	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2668	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2669			     "VIRTIO_NET_F_CTRL_VQ") ||
2670	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2671			     "VIRTIO_NET_F_CTRL_VQ") ||
2672	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2673			     "VIRTIO_NET_F_CTRL_VQ") ||
2674	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2675	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
 
 
 
 
 
 
2676			     "VIRTIO_NET_F_CTRL_VQ"))) {
2677		return false;
2678	}
2679
2680	return true;
2681}
2682
2683#define MIN_MTU ETH_MIN_MTU
2684#define MAX_MTU ETH_MAX_MTU
2685
2686static int virtnet_validate(struct virtio_device *vdev)
2687{
2688	if (!vdev->config->get) {
2689		dev_err(&vdev->dev, "%s failure: config access disabled\n",
2690			__func__);
2691		return -EINVAL;
2692	}
2693
2694	if (!virtnet_validate_features(vdev))
2695		return -EINVAL;
2696
2697	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2698		int mtu = virtio_cread16(vdev,
2699					 offsetof(struct virtio_net_config,
2700						  mtu));
2701		if (mtu < MIN_MTU)
2702			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2703	}
2704
2705	return 0;
2706}
2707
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2708static int virtnet_probe(struct virtio_device *vdev)
2709{
2710	int i, err = -ENOMEM;
2711	struct net_device *dev;
2712	struct virtnet_info *vi;
2713	u16 max_queue_pairs;
2714	int mtu;
2715
2716	/* Find if host supports multiqueue virtio_net device */
2717	err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2718				   struct virtio_net_config,
2719				   max_virtqueue_pairs, &max_queue_pairs);
 
2720
2721	/* We need at least 2 queue's */
2722	if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2723	    max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2724	    !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2725		max_queue_pairs = 1;
2726
2727	/* Allocate ourselves a network device with room for our info */
2728	dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2729	if (!dev)
2730		return -ENOMEM;
2731
2732	/* Set up network device as normal. */
2733	dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
 
2734	dev->netdev_ops = &virtnet_netdev;
2735	dev->features = NETIF_F_HIGHDMA;
2736
2737	dev->ethtool_ops = &virtnet_ethtool_ops;
2738	SET_NETDEV_DEV(dev, &vdev->dev);
2739
2740	/* Do we support "hardware" checksums? */
2741	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2742		/* This opens up the world of extra features. */
2743		dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2744		if (csum)
2745			dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2746
2747		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2748			dev->hw_features |= NETIF_F_TSO
2749				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
2750		}
2751		/* Individual feature bits: what can host handle? */
2752		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2753			dev->hw_features |= NETIF_F_TSO;
2754		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
2755			dev->hw_features |= NETIF_F_TSO6;
2756		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
2757			dev->hw_features |= NETIF_F_TSO_ECN;
 
 
2758
2759		dev->features |= NETIF_F_GSO_ROBUST;
2760
2761		if (gso)
2762			dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
2763		/* (!csum && gso) case will be fixed by register_netdev() */
2764	}
2765	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
2766		dev->features |= NETIF_F_RXCSUM;
 
 
 
 
 
2767
2768	dev->vlan_features = dev->features;
2769
2770	/* MTU range: 68 - 65535 */
2771	dev->min_mtu = MIN_MTU;
2772	dev->max_mtu = MAX_MTU;
2773
2774	/* Configuration may specify what MAC to use.  Otherwise random. */
2775	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 
 
2776		virtio_cread_bytes(vdev,
2777				   offsetof(struct virtio_net_config, mac),
2778				   dev->dev_addr, dev->addr_len);
2779	else
 
2780		eth_hw_addr_random(dev);
 
2781
2782	/* Set up our device-specific information */
2783	vi = netdev_priv(dev);
2784	vi->dev = dev;
2785	vi->vdev = vdev;
2786	vdev->priv = vi;
2787
2788	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
2789
2790	/* If we can receive ANY GSO packets, we must allocate large ones. */
2791	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2792	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2793	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
2794	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
2795		vi->big_packets = true;
2796
2797	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
2798		vi->mergeable_rx_bufs = true;
2799
2800	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
2801	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2802		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2803	else
2804		vi->hdr_len = sizeof(struct virtio_net_hdr);
2805
2806	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
2807	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2808		vi->any_header_sg = true;
2809
2810	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2811		vi->has_cvq = true;
2812
2813	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2814		mtu = virtio_cread16(vdev,
2815				     offsetof(struct virtio_net_config,
2816					      mtu));
2817		if (mtu < dev->min_mtu) {
2818			/* Should never trigger: MTU was previously validated
2819			 * in virtnet_validate.
2820			 */
2821			dev_err(&vdev->dev, "device MTU appears to have changed "
2822				"it is now %d < %d", mtu, dev->min_mtu);
 
 
2823			goto free;
2824		}
2825
2826		dev->mtu = mtu;
2827		dev->max_mtu = mtu;
2828
2829		/* TODO: size buffers correctly in this case. */
2830		if (dev->mtu > ETH_DATA_LEN)
2831			vi->big_packets = true;
2832	}
2833
 
 
2834	if (vi->any_header_sg)
2835		dev->needed_headroom = vi->hdr_len;
2836
2837	/* Enable multiqueue by default */
2838	if (num_online_cpus() >= max_queue_pairs)
2839		vi->curr_queue_pairs = max_queue_pairs;
2840	else
2841		vi->curr_queue_pairs = num_online_cpus();
2842	vi->max_queue_pairs = max_queue_pairs;
2843
2844	/* Allocate/initialize the rx/tx queues, and invoke find_vqs */
2845	err = init_vqs(vi);
2846	if (err)
2847		goto free;
2848
2849#ifdef CONFIG_SYSFS
2850	if (vi->mergeable_rx_bufs)
2851		dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
2852#endif
2853	netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
2854	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
2855
2856	virtnet_init_settings(dev);
2857
2858	err = register_netdev(dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2859	if (err) {
2860		pr_debug("virtio_net: registering device failed\n");
2861		goto free_vqs;
 
2862	}
2863
2864	virtio_device_ready(vdev);
2865
 
 
2866	err = virtnet_cpu_notif_add(vi);
2867	if (err) {
2868		pr_debug("virtio_net: registering cpu notifier failed\n");
2869		goto free_unregister_netdev;
2870	}
2871
2872	virtnet_set_queues(vi, vi->curr_queue_pairs);
2873
2874	/* Assume link up if device can't report link status,
2875	   otherwise get link status from config. */
2876	netif_carrier_off(dev);
2877	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
2878		schedule_work(&vi->config_work);
2879	} else {
2880		vi->status = VIRTIO_NET_S_LINK_UP;
2881		virtnet_update_settings(vi);
2882		netif_carrier_on(dev);
2883	}
2884
2885	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
2886		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
2887			set_bit(guest_offloads[i], &vi->guest_offloads);
 
2888
2889	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
2890		 dev->name, max_queue_pairs);
2891
2892	return 0;
2893
2894free_unregister_netdev:
2895	vi->vdev->config->reset(vdev);
2896
2897	unregister_netdev(dev);
 
 
2898free_vqs:
 
2899	cancel_delayed_work_sync(&vi->refill);
2900	free_receive_page_frags(vi);
2901	virtnet_del_vqs(vi);
2902free:
2903	free_netdev(dev);
2904	return err;
2905}
2906
2907static void remove_vq_common(struct virtnet_info *vi)
2908{
2909	vi->vdev->config->reset(vi->vdev);
2910
2911	/* Free unused buffers in both send and recv, if any. */
2912	free_unused_bufs(vi);
2913
2914	free_receive_bufs(vi);
2915
2916	free_receive_page_frags(vi);
2917
2918	virtnet_del_vqs(vi);
2919}
2920
2921static void virtnet_remove(struct virtio_device *vdev)
2922{
2923	struct virtnet_info *vi = vdev->priv;
2924
2925	virtnet_cpu_notif_remove(vi);
2926
2927	/* Make sure no work handler is accessing the device. */
2928	flush_work(&vi->config_work);
2929
2930	unregister_netdev(vi->dev);
2931
 
 
2932	remove_vq_common(vi);
2933
2934	free_netdev(vi->dev);
2935}
2936
2937static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
2938{
2939	struct virtnet_info *vi = vdev->priv;
2940
2941	virtnet_cpu_notif_remove(vi);
2942	virtnet_freeze_down(vdev);
2943	remove_vq_common(vi);
2944
2945	return 0;
2946}
2947
2948static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
2949{
2950	struct virtnet_info *vi = vdev->priv;
2951	int err;
2952
2953	err = virtnet_restore_up(vdev);
2954	if (err)
2955		return err;
2956	virtnet_set_queues(vi, vi->curr_queue_pairs);
2957
2958	err = virtnet_cpu_notif_add(vi);
2959	if (err)
 
 
2960		return err;
 
2961
2962	return 0;
2963}
2964
2965static struct virtio_device_id id_table[] = {
2966	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2967	{ 0 },
2968};
2969
2970#define VIRTNET_FEATURES \
2971	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
2972	VIRTIO_NET_F_MAC, \
2973	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
2974	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
2975	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
 
2976	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
2977	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
2978	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
2979	VIRTIO_NET_F_CTRL_MAC_ADDR, \
2980	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
2981	VIRTIO_NET_F_SPEED_DUPLEX
 
2982
2983static unsigned int features[] = {
2984	VIRTNET_FEATURES,
2985};
2986
2987static unsigned int features_legacy[] = {
2988	VIRTNET_FEATURES,
2989	VIRTIO_NET_F_GSO,
2990	VIRTIO_F_ANY_LAYOUT,
2991};
2992
2993static struct virtio_driver virtio_net_driver = {
2994	.feature_table = features,
2995	.feature_table_size = ARRAY_SIZE(features),
2996	.feature_table_legacy = features_legacy,
2997	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
2998	.driver.name =	KBUILD_MODNAME,
2999	.driver.owner =	THIS_MODULE,
3000	.id_table =	id_table,
3001	.validate =	virtnet_validate,
3002	.probe =	virtnet_probe,
3003	.remove =	virtnet_remove,
3004	.config_changed = virtnet_config_changed,
3005#ifdef CONFIG_PM_SLEEP
3006	.freeze =	virtnet_freeze,
3007	.restore =	virtnet_restore,
3008#endif
3009};
3010
3011static __init int virtio_net_driver_init(void)
3012{
3013	int ret;
3014
3015	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3016				      virtnet_cpu_online,
3017				      virtnet_cpu_down_prep);
3018	if (ret < 0)
3019		goto out;
3020	virtionet_online = ret;
3021	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3022				      NULL, virtnet_cpu_dead);
3023	if (ret)
3024		goto err_dead;
3025
3026        ret = register_virtio_driver(&virtio_net_driver);
3027	if (ret)
3028		goto err_virtio;
3029	return 0;
3030err_virtio:
3031	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3032err_dead:
3033	cpuhp_remove_multi_state(virtionet_online);
3034out:
3035	return ret;
3036}
3037module_init(virtio_net_driver_init);
3038
3039static __exit void virtio_net_driver_exit(void)
3040{
3041	unregister_virtio_driver(&virtio_net_driver);
3042	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3043	cpuhp_remove_multi_state(virtionet_online);
3044}
3045module_exit(virtio_net_driver_exit);
3046
3047MODULE_DEVICE_TABLE(virtio, id_table);
3048MODULE_DESCRIPTION("Virtio network driver");
3049MODULE_LICENSE("GPL");
v6.2
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* A network driver using virtio.
   3 *
   4 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
 
 
 
 
 
 
 
 
 
 
 
 
 
   5 */
   6//#define DEBUG
   7#include <linux/netdevice.h>
   8#include <linux/etherdevice.h>
   9#include <linux/ethtool.h>
  10#include <linux/module.h>
  11#include <linux/virtio.h>
  12#include <linux/virtio_net.h>
  13#include <linux/bpf.h>
  14#include <linux/bpf_trace.h>
  15#include <linux/scatterlist.h>
  16#include <linux/if_vlan.h>
  17#include <linux/slab.h>
  18#include <linux/cpu.h>
  19#include <linux/average.h>
  20#include <linux/filter.h>
  21#include <linux/kernel.h>
  22#include <net/route.h>
  23#include <net/xdp.h>
  24#include <net/net_failover.h>
  25
  26static int napi_weight = NAPI_POLL_WEIGHT;
  27module_param(napi_weight, int, 0444);
  28
  29static bool csum = true, gso = true, napi_tx = true;
  30module_param(csum, bool, 0444);
  31module_param(gso, bool, 0444);
  32module_param(napi_tx, bool, 0644);
  33
  34/* FIXME: MTU in config. */
  35#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  36#define GOOD_COPY_LEN	128
  37
  38#define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
  39
  40/* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
  41#define VIRTIO_XDP_HEADROOM 256
  42
  43/* Separating two types of XDP xmit */
  44#define VIRTIO_XDP_TX		BIT(0)
  45#define VIRTIO_XDP_REDIR	BIT(1)
  46
  47#define VIRTIO_XDP_FLAG	BIT(0)
  48
  49/* RX packet size EWMA. The average packet size is used to determine the packet
  50 * buffer size when refilling RX rings. As the entire RX ring may be refilled
  51 * at once, the weight is chosen so that the EWMA will be insensitive to short-
  52 * term, transient changes in packet size.
  53 */
  54DECLARE_EWMA(pkt_len, 0, 64)
  55
  56#define VIRTNET_DRIVER_VERSION "1.0.0"
  57
  58static const unsigned long guest_offloads[] = {
  59	VIRTIO_NET_F_GUEST_TSO4,
  60	VIRTIO_NET_F_GUEST_TSO6,
  61	VIRTIO_NET_F_GUEST_ECN,
  62	VIRTIO_NET_F_GUEST_UFO,
  63	VIRTIO_NET_F_GUEST_CSUM,
  64	VIRTIO_NET_F_GUEST_USO4,
  65	VIRTIO_NET_F_GUEST_USO6
  66};
  67
  68#define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
  69				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
  70				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
  71				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
  72				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
  73				(1ULL << VIRTIO_NET_F_GUEST_USO6))
  74
  75struct virtnet_stat_desc {
  76	char desc[ETH_GSTRING_LEN];
  77	size_t offset;
  78};
  79
  80struct virtnet_sq_stats {
  81	struct u64_stats_sync syncp;
  82	u64 packets;
  83	u64 bytes;
  84	u64 xdp_tx;
  85	u64 xdp_tx_drops;
  86	u64 kicks;
  87	u64 tx_timeouts;
  88};
  89
  90struct virtnet_rq_stats {
  91	struct u64_stats_sync syncp;
  92	u64 packets;
  93	u64 bytes;
  94	u64 drops;
  95	u64 xdp_packets;
  96	u64 xdp_tx;
  97	u64 xdp_redirects;
  98	u64 xdp_drops;
  99	u64 kicks;
 100};
 101
 102#define VIRTNET_SQ_STAT(m)	offsetof(struct virtnet_sq_stats, m)
 103#define VIRTNET_RQ_STAT(m)	offsetof(struct virtnet_rq_stats, m)
 104
 105static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
 106	{ "packets",		VIRTNET_SQ_STAT(packets) },
 107	{ "bytes",		VIRTNET_SQ_STAT(bytes) },
 108	{ "xdp_tx",		VIRTNET_SQ_STAT(xdp_tx) },
 109	{ "xdp_tx_drops",	VIRTNET_SQ_STAT(xdp_tx_drops) },
 110	{ "kicks",		VIRTNET_SQ_STAT(kicks) },
 111	{ "tx_timeouts",	VIRTNET_SQ_STAT(tx_timeouts) },
 112};
 113
 114static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
 115	{ "packets",		VIRTNET_RQ_STAT(packets) },
 116	{ "bytes",		VIRTNET_RQ_STAT(bytes) },
 117	{ "drops",		VIRTNET_RQ_STAT(drops) },
 118	{ "xdp_packets",	VIRTNET_RQ_STAT(xdp_packets) },
 119	{ "xdp_tx",		VIRTNET_RQ_STAT(xdp_tx) },
 120	{ "xdp_redirects",	VIRTNET_RQ_STAT(xdp_redirects) },
 121	{ "xdp_drops",		VIRTNET_RQ_STAT(xdp_drops) },
 122	{ "kicks",		VIRTNET_RQ_STAT(kicks) },
 123};
 124
 125#define VIRTNET_SQ_STATS_LEN	ARRAY_SIZE(virtnet_sq_stats_desc)
 126#define VIRTNET_RQ_STATS_LEN	ARRAY_SIZE(virtnet_rq_stats_desc)
 127
 128/* Internal representation of a send virtqueue */
 129struct send_queue {
 130	/* Virtqueue associated with this send _queue */
 131	struct virtqueue *vq;
 132
 133	/* TX: fragments + linear part + virtio header */
 134	struct scatterlist sg[MAX_SKB_FRAGS + 2];
 135
 136	/* Name of the send queue: output.$index */
 137	char name[40];
 138
 139	struct virtnet_sq_stats stats;
 140
 141	struct napi_struct napi;
 142
 143	/* Record whether sq is in reset state. */
 144	bool reset;
 145};
 146
 147/* Internal representation of a receive virtqueue */
 148struct receive_queue {
 149	/* Virtqueue associated with this receive_queue */
 150	struct virtqueue *vq;
 151
 152	struct napi_struct napi;
 153
 154	struct bpf_prog __rcu *xdp_prog;
 155
 156	struct virtnet_rq_stats stats;
 157
 158	/* Chain pages by the private ptr. */
 159	struct page *pages;
 160
 161	/* Average packet length for mergeable receive buffers. */
 162	struct ewma_pkt_len mrg_avg_pkt_len;
 163
 164	/* Page frag for packet buffer allocation. */
 165	struct page_frag alloc_frag;
 166
 167	/* RX: fragments + linear part + virtio header */
 168	struct scatterlist sg[MAX_SKB_FRAGS + 2];
 169
 170	/* Min single buffer size for mergeable buffers case. */
 171	unsigned int min_buf_len;
 172
 173	/* Name of this receive queue: input.$index */
 174	char name[40];
 175
 176	struct xdp_rxq_info xdp_rxq;
 177};
 178
 179/* This structure can contain rss message with maximum settings for indirection table and keysize
 180 * Note, that default structure that describes RSS configuration virtio_net_rss_config
 181 * contains same info but can't handle table values.
 182 * In any case, structure would be passed to virtio hw through sg_buf split by parts
 183 * because table sizes may be differ according to the device configuration.
 184 */
 185#define VIRTIO_NET_RSS_MAX_KEY_SIZE     40
 186#define VIRTIO_NET_RSS_MAX_TABLE_LEN    128
 187struct virtio_net_ctrl_rss {
 188	u32 hash_types;
 189	u16 indirection_table_mask;
 190	u16 unclassified_queue;
 191	u16 indirection_table[VIRTIO_NET_RSS_MAX_TABLE_LEN];
 192	u16 max_tx_vq;
 193	u8 hash_key_length;
 194	u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
 195};
 196
 197/* Control VQ buffers: protected by the rtnl lock */
 198struct control_buf {
 199	struct virtio_net_ctrl_hdr hdr;
 200	virtio_net_ctrl_ack status;
 201	struct virtio_net_ctrl_mq mq;
 202	u8 promisc;
 203	u8 allmulti;
 204	__virtio16 vid;
 205	__virtio64 offloads;
 206	struct virtio_net_ctrl_rss rss;
 207};
 208
 209struct virtnet_info {
 210	struct virtio_device *vdev;
 211	struct virtqueue *cvq;
 212	struct net_device *dev;
 213	struct send_queue *sq;
 214	struct receive_queue *rq;
 215	unsigned int status;
 216
 217	/* Max # of queue pairs supported by the device */
 218	u16 max_queue_pairs;
 219
 220	/* # of queue pairs currently used by the driver */
 221	u16 curr_queue_pairs;
 222
 223	/* # of XDP queue pairs currently used by the driver */
 224	u16 xdp_queue_pairs;
 225
 226	/* xdp_queue_pairs may be 0, when xdp is already loaded. So add this. */
 227	bool xdp_enabled;
 228
 229	/* I like... big packets and I cannot lie! */
 230	bool big_packets;
 231
 232	/* number of sg entries allocated for big packets */
 233	unsigned int big_packets_num_skbfrags;
 234
 235	/* Host will merge rx buffers for big packets (shake it! shake it!) */
 236	bool mergeable_rx_bufs;
 237
 238	/* Host supports rss and/or hash report */
 239	bool has_rss;
 240	bool has_rss_hash_report;
 241	u8 rss_key_size;
 242	u16 rss_indir_table_size;
 243	u32 rss_hash_types_supported;
 244	u32 rss_hash_types_saved;
 245
 246	/* Has control virtqueue */
 247	bool has_cvq;
 248
 249	/* Host can handle any s/g split between our header and packet data */
 250	bool any_header_sg;
 251
 252	/* Packet virtio header size */
 253	u8 hdr_len;
 254
 255	/* Work struct for delayed refilling if we run low on memory. */
 256	struct delayed_work refill;
 257
 258	/* Is delayed refill enabled? */
 259	bool refill_enabled;
 260
 261	/* The lock to synchronize the access to refill_enabled */
 262	spinlock_t refill_lock;
 263
 264	/* Work struct for config space updates */
 265	struct work_struct config_work;
 266
 267	/* Does the affinity hint is set for virtqueues? */
 268	bool affinity_hint_set;
 269
 270	/* CPU hotplug instances for online & dead */
 271	struct hlist_node node;
 272	struct hlist_node node_dead;
 273
 274	struct control_buf *ctrl;
 275
 276	/* Ethtool settings */
 277	u8 duplex;
 278	u32 speed;
 279
 280	/* Interrupt coalescing settings */
 281	u32 tx_usecs;
 282	u32 rx_usecs;
 283	u32 tx_max_packets;
 284	u32 rx_max_packets;
 285
 286	unsigned long guest_offloads;
 287	unsigned long guest_offloads_capable;
 288
 289	/* failover when STANDBY feature enabled */
 290	struct failover *failover;
 291};
 292
 293struct padded_vnet_hdr {
 294	struct virtio_net_hdr_v1_hash hdr;
 295	/*
 296	 * hdr is in a separate sg buffer, and data sg buffer shares same page
 297	 * with this header sg. This padding makes next sg 16 byte aligned
 298	 * after the header.
 299	 */
 300	char padding[12];
 301};
 302
 303static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
 304static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
 305
 306static bool is_xdp_frame(void *ptr)
 307{
 308	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
 309}
 310
 311static void *xdp_to_ptr(struct xdp_frame *ptr)
 312{
 313	return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
 314}
 315
 316static struct xdp_frame *ptr_to_xdp(void *ptr)
 317{
 318	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
 319}
 320
 321/* Converting between virtqueue no. and kernel tx/rx queue no.
 322 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 323 */
 324static int vq2txq(struct virtqueue *vq)
 325{
 326	return (vq->index - 1) / 2;
 327}
 328
 329static int txq2vq(int txq)
 330{
 331	return txq * 2 + 1;
 332}
 333
 334static int vq2rxq(struct virtqueue *vq)
 335{
 336	return vq->index / 2;
 337}
 338
 339static int rxq2vq(int rxq)
 340{
 341	return rxq * 2;
 342}
 343
 344static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 345{
 346	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 347}
 348
 349/*
 350 * private is used to chain pages for big packets, put the whole
 351 * most recent used list in the beginning for reuse
 352 */
 353static void give_pages(struct receive_queue *rq, struct page *page)
 354{
 355	struct page *end;
 356
 357	/* Find end of list, sew whole thing into vi->rq.pages. */
 358	for (end = page; end->private; end = (struct page *)end->private);
 359	end->private = (unsigned long)rq->pages;
 360	rq->pages = page;
 361}
 362
 363static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 364{
 365	struct page *p = rq->pages;
 366
 367	if (p) {
 368		rq->pages = (struct page *)p->private;
 369		/* clear private here, it is used to chain pages */
 370		p->private = 0;
 371	} else
 372		p = alloc_page(gfp_mask);
 373	return p;
 374}
 375
 376static void enable_delayed_refill(struct virtnet_info *vi)
 377{
 378	spin_lock_bh(&vi->refill_lock);
 379	vi->refill_enabled = true;
 380	spin_unlock_bh(&vi->refill_lock);
 381}
 382
 383static void disable_delayed_refill(struct virtnet_info *vi)
 384{
 385	spin_lock_bh(&vi->refill_lock);
 386	vi->refill_enabled = false;
 387	spin_unlock_bh(&vi->refill_lock);
 388}
 389
 390static void virtqueue_napi_schedule(struct napi_struct *napi,
 391				    struct virtqueue *vq)
 392{
 393	if (napi_schedule_prep(napi)) {
 394		virtqueue_disable_cb(vq);
 395		__napi_schedule(napi);
 396	}
 397}
 398
 399static void virtqueue_napi_complete(struct napi_struct *napi,
 400				    struct virtqueue *vq, int processed)
 401{
 402	int opaque;
 403
 404	opaque = virtqueue_enable_cb_prepare(vq);
 405	if (napi_complete_done(napi, processed)) {
 406		if (unlikely(virtqueue_poll(vq, opaque)))
 407			virtqueue_napi_schedule(napi, vq);
 408	} else {
 409		virtqueue_disable_cb(vq);
 410	}
 411}
 412
 413static void skb_xmit_done(struct virtqueue *vq)
 414{
 415	struct virtnet_info *vi = vq->vdev->priv;
 416	struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
 417
 418	/* Suppress further interrupts. */
 419	virtqueue_disable_cb(vq);
 420
 421	if (napi->weight)
 422		virtqueue_napi_schedule(napi, vq);
 423	else
 424		/* We were probably waiting for more output buffers. */
 425		netif_wake_subqueue(vi->dev, vq2txq(vq));
 426}
 427
 428#define MRG_CTX_HEADER_SHIFT 22
 429static void *mergeable_len_to_ctx(unsigned int truesize,
 430				  unsigned int headroom)
 431{
 432	return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
 433}
 434
 435static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 436{
 437	return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 438}
 439
 440static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
 441{
 442	return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
 443}
 444
 445/* Called from bottom half context */
 446static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 447				   struct receive_queue *rq,
 448				   struct page *page, unsigned int offset,
 449				   unsigned int len, unsigned int truesize,
 450				   bool hdr_valid, unsigned int metasize,
 451				   unsigned int headroom)
 452{
 453	struct sk_buff *skb;
 454	struct virtio_net_hdr_mrg_rxbuf *hdr;
 455	unsigned int copy, hdr_len, hdr_padded_len;
 456	struct page *page_to_free = NULL;
 457	int tailroom, shinfo_size;
 458	char *p, *hdr_p, *buf;
 459
 460	p = page_address(page) + offset;
 461	hdr_p = p;
 
 
 
 
 
 
 462
 463	hdr_len = vi->hdr_len;
 464	if (vi->mergeable_rx_bufs)
 465		hdr_padded_len = hdr_len;
 466	else
 467		hdr_padded_len = sizeof(struct padded_vnet_hdr);
 468
 469	/* If headroom is not 0, there is an offset between the beginning of the
 470	 * data and the allocated space, otherwise the data and the allocated
 471	 * space are aligned.
 472	 *
 473	 * Buffers with headroom use PAGE_SIZE as alloc size, see
 474	 * add_recvbuf_mergeable() + get_mergeable_buf_len()
 475	 */
 476	truesize = headroom ? PAGE_SIZE : truesize;
 477	tailroom = truesize - headroom;
 478	buf = p - headroom;
 479
 480	len -= hdr_len;
 481	offset += hdr_padded_len;
 482	p += hdr_padded_len;
 483	tailroom -= hdr_padded_len + len;
 484
 485	shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 486
 487	/* copy small packet so we can reuse these pages */
 488	if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) {
 489		skb = build_skb(buf, truesize);
 490		if (unlikely(!skb))
 491			return NULL;
 492
 493		skb_reserve(skb, p - buf);
 494		skb_put(skb, len);
 495
 496		page = (struct page *)page->private;
 497		if (page)
 498			give_pages(rq, page);
 499		goto ok;
 500	}
 501
 502	/* copy small packet so we can reuse these pages for small data */
 503	skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 504	if (unlikely(!skb))
 505		return NULL;
 506
 507	/* Copy all frame if it fits skb->head, otherwise
 508	 * we let virtio_net_hdr_to_skb() and GRO pull headers as needed.
 509	 */
 510	if (len <= skb_tailroom(skb))
 511		copy = len;
 512	else
 513		copy = ETH_HLEN + metasize;
 514	skb_put_data(skb, p, copy);
 515
 516	len -= copy;
 517	offset += copy;
 518
 519	if (vi->mergeable_rx_bufs) {
 520		if (len)
 521			skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 522		else
 523			page_to_free = page;
 524		goto ok;
 525	}
 526
 527	/*
 528	 * Verify that we can indeed put this data into a skb.
 529	 * This is here to handle cases when the device erroneously
 530	 * tries to receive more than is possible. This is usually
 531	 * the case of a broken device.
 532	 */
 533	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 534		net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 535		dev_kfree_skb(skb);
 536		return NULL;
 537	}
 538	BUG_ON(offset >= PAGE_SIZE);
 539	while (len) {
 540		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 541		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 542				frag_size, truesize);
 543		len -= frag_size;
 544		page = (struct page *)page->private;
 545		offset = 0;
 546	}
 547
 548	if (page)
 549		give_pages(rq, page);
 550
 551ok:
 552	/* hdr_valid means no XDP, so we can copy the vnet header */
 553	if (hdr_valid) {
 554		hdr = skb_vnet_hdr(skb);
 555		memcpy(hdr, hdr_p, hdr_len);
 556	}
 557	if (page_to_free)
 558		put_page(page_to_free);
 559
 560	if (metasize) {
 561		__skb_pull(skb, metasize);
 562		skb_metadata_set(skb, metasize);
 563	}
 564
 565	return skb;
 566}
 567
 568static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
 569				   struct send_queue *sq,
 570				   struct xdp_frame *xdpf)
 571{
 572	struct virtio_net_hdr_mrg_rxbuf *hdr;
 
 
 
 
 573	int err;
 574
 575	if (unlikely(xdpf->headroom < vi->hdr_len))
 576		return -EOVERFLOW;
 577
 578	/* Make room for virtqueue hdr (also change xdpf->headroom?) */
 579	xdpf->data -= vi->hdr_len;
 
 
 
 
 
 
 580	/* Zero header and leave csum up to XDP layers */
 581	hdr = xdpf->data;
 582	memset(hdr, 0, vi->hdr_len);
 583	xdpf->len   += vi->hdr_len;
 584
 585	sg_init_one(sq->sg, xdpf->data, xdpf->len);
 586
 587	err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
 588				   GFP_ATOMIC);
 589	if (unlikely(err))
 590		return -ENOSPC; /* Caller handle free/refcnt */
 591
 592	return 0;
 593}
 594
 595/* when vi->curr_queue_pairs > nr_cpu_ids, the txq/sq is only used for xdp tx on
 596 * the current cpu, so it does not need to be locked.
 597 *
 598 * Here we use marco instead of inline functions because we have to deal with
 599 * three issues at the same time: 1. the choice of sq. 2. judge and execute the
 600 * lock/unlock of txq 3. make sparse happy. It is difficult for two inline
 601 * functions to perfectly solve these three problems at the same time.
 602 */
 603#define virtnet_xdp_get_sq(vi) ({                                       \
 604	int cpu = smp_processor_id();                                   \
 605	struct netdev_queue *txq;                                       \
 606	typeof(vi) v = (vi);                                            \
 607	unsigned int qp;                                                \
 608									\
 609	if (v->curr_queue_pairs > nr_cpu_ids) {                         \
 610		qp = v->curr_queue_pairs - v->xdp_queue_pairs;          \
 611		qp += cpu;                                              \
 612		txq = netdev_get_tx_queue(v->dev, qp);                  \
 613		__netif_tx_acquire(txq);                                \
 614	} else {                                                        \
 615		qp = cpu % v->curr_queue_pairs;                         \
 616		txq = netdev_get_tx_queue(v->dev, qp);                  \
 617		__netif_tx_lock(txq, cpu);                              \
 618	}                                                               \
 619	v->sq + qp;                                                     \
 620})
 621
 622#define virtnet_xdp_put_sq(vi, q) {                                     \
 623	struct netdev_queue *txq;                                       \
 624	typeof(vi) v = (vi);                                            \
 625									\
 626	txq = netdev_get_tx_queue(v->dev, (q) - v->sq);                 \
 627	if (v->curr_queue_pairs > nr_cpu_ids)                           \
 628		__netif_tx_release(txq);                                \
 629	else                                                            \
 630		__netif_tx_unlock(txq);                                 \
 631}
 632
 633static int virtnet_xdp_xmit(struct net_device *dev,
 634			    int n, struct xdp_frame **frames, u32 flags)
 635{
 636	struct virtnet_info *vi = netdev_priv(dev);
 637	struct receive_queue *rq = vi->rq;
 638	struct bpf_prog *xdp_prog;
 639	struct send_queue *sq;
 640	unsigned int len;
 641	int packets = 0;
 642	int bytes = 0;
 643	int nxmit = 0;
 644	int kicks = 0;
 645	void *ptr;
 646	int ret;
 647	int i;
 648
 649	/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 650	 * indicate XDP resources have been successfully allocated.
 651	 */
 652	xdp_prog = rcu_access_pointer(rq->xdp_prog);
 653	if (!xdp_prog)
 654		return -ENXIO;
 655
 656	sq = virtnet_xdp_get_sq(vi);
 657
 658	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
 659		ret = -EINVAL;
 660		goto out;
 661	}
 662
 663	/* Free up any pending old buffers before queueing new ones. */
 664	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 665		if (likely(is_xdp_frame(ptr))) {
 666			struct xdp_frame *frame = ptr_to_xdp(ptr);
 667
 668			bytes += frame->len;
 669			xdp_return_frame(frame);
 670		} else {
 671			struct sk_buff *skb = ptr;
 672
 673			bytes += skb->len;
 674			napi_consume_skb(skb, false);
 675		}
 676		packets++;
 677	}
 678
 679	for (i = 0; i < n; i++) {
 680		struct xdp_frame *xdpf = frames[i];
 681
 682		if (__virtnet_xdp_xmit_one(vi, sq, xdpf))
 683			break;
 684		nxmit++;
 685	}
 686	ret = nxmit;
 687
 688	if (flags & XDP_XMIT_FLUSH) {
 689		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
 690			kicks = 1;
 691	}
 692out:
 693	u64_stats_update_begin(&sq->stats.syncp);
 694	sq->stats.bytes += bytes;
 695	sq->stats.packets += packets;
 696	sq->stats.xdp_tx += n;
 697	sq->stats.xdp_tx_drops += n - nxmit;
 698	sq->stats.kicks += kicks;
 699	u64_stats_update_end(&sq->stats.syncp);
 700
 701	virtnet_xdp_put_sq(vi, sq);
 702	return ret;
 703}
 704
 705static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
 706{
 707	return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
 708}
 709
 710/* We copy the packet for XDP in the following cases:
 711 *
 712 * 1) Packet is scattered across multiple rx buffers.
 713 * 2) Headroom space is insufficient.
 714 *
 715 * This is inefficient but it's a temporary condition that
 716 * we hit right after XDP is enabled and until queue is refilled
 717 * with large buffers with sufficient headroom - so it should affect
 718 * at most queue size packets.
 719 * Afterwards, the conditions to enable
 720 * XDP should preclude the underlying device from sending packets
 721 * across multiple buffers (num_buf > 1), and we make sure buffers
 722 * have enough headroom.
 723 */
 724static struct page *xdp_linearize_page(struct receive_queue *rq,
 725				       u16 *num_buf,
 726				       struct page *p,
 727				       int offset,
 728				       int page_off,
 729				       unsigned int *len)
 730{
 731	struct page *page = alloc_page(GFP_ATOMIC);
 732
 733	if (!page)
 734		return NULL;
 735
 736	memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 737	page_off += *len;
 738
 739	while (--*num_buf) {
 740		int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 741		unsigned int buflen;
 742		void *buf;
 743		int off;
 744
 745		buf = virtqueue_get_buf(rq->vq, &buflen);
 746		if (unlikely(!buf))
 747			goto err_buf;
 748
 749		p = virt_to_head_page(buf);
 750		off = buf - page_address(p);
 751
 752		/* guard against a misconfigured or uncooperative backend that
 753		 * is sending packet larger than the MTU.
 754		 */
 755		if ((page_off + buflen + tailroom) > PAGE_SIZE) {
 756			put_page(p);
 757			goto err_buf;
 758		}
 759
 760		memcpy(page_address(page) + page_off,
 761		       page_address(p) + off, buflen);
 762		page_off += buflen;
 763		put_page(p);
 764	}
 765
 766	/* Headroom does not contribute to packet length */
 767	*len = page_off - VIRTIO_XDP_HEADROOM;
 768	return page;
 769err_buf:
 770	__free_pages(page, 0);
 771	return NULL;
 772}
 773
 774static struct sk_buff *receive_small(struct net_device *dev,
 775				     struct virtnet_info *vi,
 776				     struct receive_queue *rq,
 777				     void *buf, void *ctx,
 778				     unsigned int len,
 779				     unsigned int *xdp_xmit,
 780				     struct virtnet_rq_stats *stats)
 781{
 782	struct sk_buff *skb;
 783	struct bpf_prog *xdp_prog;
 784	unsigned int xdp_headroom = (unsigned long)ctx;
 785	unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
 786	unsigned int headroom = vi->hdr_len + header_offset;
 787	unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 788			      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 789	struct page *page = virt_to_head_page(buf);
 790	unsigned int delta = 0;
 791	struct page *xdp_page;
 
 792	int err;
 793	unsigned int metasize = 0;
 794
 795	len -= vi->hdr_len;
 796	stats->bytes += len;
 797
 798	if (unlikely(len > GOOD_PACKET_LEN)) {
 799		pr_debug("%s: rx error: len %u exceeds max size %d\n",
 800			 dev->name, len, GOOD_PACKET_LEN);
 801		dev->stats.rx_length_errors++;
 802		goto err;
 803	}
 804
 805	if (likely(!vi->xdp_enabled)) {
 806		xdp_prog = NULL;
 807		goto skip_xdp;
 808	}
 809
 810	rcu_read_lock();
 811	xdp_prog = rcu_dereference(rq->xdp_prog);
 812	if (xdp_prog) {
 813		struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
 814		struct xdp_frame *xdpf;
 815		struct xdp_buff xdp;
 816		void *orig_data;
 817		u32 act;
 818
 819		if (unlikely(hdr->hdr.gso_type))
 820			goto err_xdp;
 821
 822		if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
 823			int offset = buf - page_address(page) + header_offset;
 824			unsigned int tlen = len + vi->hdr_len;
 825			u16 num_buf = 1;
 826
 827			xdp_headroom = virtnet_get_headroom(vi);
 828			header_offset = VIRTNET_RX_PAD + xdp_headroom;
 829			headroom = vi->hdr_len + header_offset;
 830			buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 831				 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 832			xdp_page = xdp_linearize_page(rq, &num_buf, page,
 833						      offset, header_offset,
 834						      &tlen);
 835			if (!xdp_page)
 836				goto err_xdp;
 837
 838			buf = page_address(xdp_page);
 839			put_page(page);
 840			page = xdp_page;
 841		}
 842
 843		xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
 844		xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
 845				 xdp_headroom, len, true);
 
 
 846		orig_data = xdp.data;
 847		act = bpf_prog_run_xdp(xdp_prog, &xdp);
 848		stats->xdp_packets++;
 849
 850		switch (act) {
 851		case XDP_PASS:
 852			/* Recalculate length in case bpf program changed it */
 853			delta = orig_data - xdp.data;
 854			len = xdp.data_end - xdp.data;
 855			metasize = xdp.data - xdp.data_meta;
 856			break;
 857		case XDP_TX:
 858			stats->xdp_tx++;
 859			xdpf = xdp_convert_buff_to_frame(&xdp);
 860			if (unlikely(!xdpf))
 861				goto err_xdp;
 862			err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 863			if (unlikely(!err)) {
 864				xdp_return_frame_rx_napi(xdpf);
 865			} else if (unlikely(err < 0)) {
 866				trace_xdp_exception(vi->dev, xdp_prog, act);
 867				goto err_xdp;
 868			}
 869			*xdp_xmit |= VIRTIO_XDP_TX;
 870			rcu_read_unlock();
 871			goto xdp_xmit;
 872		case XDP_REDIRECT:
 873			stats->xdp_redirects++;
 874			err = xdp_do_redirect(dev, &xdp, xdp_prog);
 875			if (err)
 876				goto err_xdp;
 877			*xdp_xmit |= VIRTIO_XDP_REDIR;
 878			rcu_read_unlock();
 879			goto xdp_xmit;
 880		default:
 881			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
 882			fallthrough;
 883		case XDP_ABORTED:
 884			trace_xdp_exception(vi->dev, xdp_prog, act);
 885			goto err_xdp;
 886		case XDP_DROP:
 887			goto err_xdp;
 888		}
 889	}
 890	rcu_read_unlock();
 891
 892skip_xdp:
 893	skb = build_skb(buf, buflen);
 894	if (!skb)
 
 895		goto err;
 
 896	skb_reserve(skb, headroom - delta);
 897	skb_put(skb, len);
 898	if (!xdp_prog) {
 899		buf += header_offset;
 900		memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
 901	} /* keep zeroed vnet hdr since XDP is loaded */
 902
 903	if (metasize)
 904		skb_metadata_set(skb, metasize);
 905
 
 906	return skb;
 907
 908err_xdp:
 909	rcu_read_unlock();
 910	stats->xdp_drops++;
 911err:
 912	stats->drops++;
 913	put_page(page);
 914xdp_xmit:
 915	return NULL;
 916}
 917
 918static struct sk_buff *receive_big(struct net_device *dev,
 919				   struct virtnet_info *vi,
 920				   struct receive_queue *rq,
 921				   void *buf,
 922				   unsigned int len,
 923				   struct virtnet_rq_stats *stats)
 924{
 925	struct page *page = buf;
 926	struct sk_buff *skb =
 927		page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0, 0);
 928
 929	stats->bytes += len - vi->hdr_len;
 930	if (unlikely(!skb))
 931		goto err;
 932
 933	return skb;
 934
 935err:
 936	stats->drops++;
 937	give_pages(rq, page);
 938	return NULL;
 939}
 940
 941static struct sk_buff *receive_mergeable(struct net_device *dev,
 942					 struct virtnet_info *vi,
 943					 struct receive_queue *rq,
 944					 void *buf,
 945					 void *ctx,
 946					 unsigned int len,
 947					 unsigned int *xdp_xmit,
 948					 struct virtnet_rq_stats *stats)
 949{
 950	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 951	u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 952	struct page *page = virt_to_head_page(buf);
 953	int offset = buf - page_address(page);
 954	struct sk_buff *head_skb, *curr_skb;
 955	struct bpf_prog *xdp_prog;
 956	unsigned int truesize = mergeable_ctx_to_truesize(ctx);
 957	unsigned int headroom = mergeable_ctx_to_headroom(ctx);
 958	unsigned int metasize = 0;
 959	unsigned int frame_sz;
 960	int err;
 961
 962	head_skb = NULL;
 963	stats->bytes += len - vi->hdr_len;
 964
 965	if (unlikely(len > truesize)) {
 966		pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 967			 dev->name, len, (unsigned long)ctx);
 968		dev->stats.rx_length_errors++;
 969		goto err_skb;
 970	}
 971
 972	if (likely(!vi->xdp_enabled)) {
 973		xdp_prog = NULL;
 974		goto skip_xdp;
 975	}
 976
 977	rcu_read_lock();
 978	xdp_prog = rcu_dereference(rq->xdp_prog);
 979	if (xdp_prog) {
 980		struct xdp_frame *xdpf;
 981		struct page *xdp_page;
 982		struct xdp_buff xdp;
 983		void *data;
 984		u32 act;
 985
 986		/* Transient failure which in theory could occur if
 987		 * in-flight packets from before XDP was enabled reach
 988		 * the receive path after XDP is loaded.
 989		 */
 990		if (unlikely(hdr->hdr.gso_type))
 991			goto err_xdp;
 992
 993		/* Buffers with headroom use PAGE_SIZE as alloc size,
 994		 * see add_recvbuf_mergeable() + get_mergeable_buf_len()
 995		 */
 996		frame_sz = headroom ? PAGE_SIZE : truesize;
 997
 998		/* This happens when rx buffer size is underestimated
 999		 * or headroom is not enough because of the buffer
1000		 * was refilled before XDP is set. This should only
1001		 * happen for the first several packets, so we don't
1002		 * care much about its performance.
1003		 */
1004		if (unlikely(num_buf > 1 ||
1005			     headroom < virtnet_get_headroom(vi))) {
1006			/* linearize data for XDP */
1007			xdp_page = xdp_linearize_page(rq, &num_buf,
1008						      page, offset,
1009						      VIRTIO_XDP_HEADROOM,
1010						      &len);
1011			frame_sz = PAGE_SIZE;
1012
1013			if (!xdp_page)
1014				goto err_xdp;
1015			offset = VIRTIO_XDP_HEADROOM;
1016		} else {
1017			xdp_page = page;
1018		}
1019
1020		/* Allow consuming headroom but reserve enough space to push
1021		 * the descriptor on if we get an XDP_TX return code.
1022		 */
1023		data = page_address(xdp_page) + offset;
1024		xdp_init_buff(&xdp, frame_sz - vi->hdr_len, &rq->xdp_rxq);
1025		xdp_prepare_buff(&xdp, data - VIRTIO_XDP_HEADROOM + vi->hdr_len,
1026				 VIRTIO_XDP_HEADROOM, len - vi->hdr_len, true);
 
 
1027
1028		act = bpf_prog_run_xdp(xdp_prog, &xdp);
1029		stats->xdp_packets++;
1030
1031		switch (act) {
1032		case XDP_PASS:
1033			metasize = xdp.data - xdp.data_meta;
1034
1035			/* recalculate offset to account for any header
1036			 * adjustments and minus the metasize to copy the
1037			 * metadata in page_to_skb(). Note other cases do not
1038			 * build an skb and avoid using offset
1039			 */
1040			offset = xdp.data - page_address(xdp_page) -
1041				 vi->hdr_len - metasize;
1042
1043			/* recalculate len if xdp.data, xdp.data_end or
1044			 * xdp.data_meta were adjusted
1045			 */
1046			len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
1047
1048			/* recalculate headroom if xdp.data or xdp_data_meta
1049			 * were adjusted, note that offset should always point
1050			 * to the start of the reserved bytes for virtio_net
1051			 * header which are followed by xdp.data, that means
1052			 * that offset is equal to the headroom (when buf is
1053			 * starting at the beginning of the page, otherwise
1054			 * there is a base offset inside the page) but it's used
1055			 * with a different starting point (buf start) than
1056			 * xdp.data (buf start + vnet hdr size). If xdp.data or
1057			 * data_meta were adjusted by the xdp prog then the
1058			 * headroom size has changed and so has the offset, we
1059			 * can use data_hard_start, which points at buf start +
1060			 * vnet hdr size, to calculate the new headroom and use
1061			 * it later to compute buf start in page_to_skb()
1062			 */
1063			headroom = xdp.data - xdp.data_hard_start - metasize;
1064
1065			/* We can only create skb based on xdp_page. */
1066			if (unlikely(xdp_page != page)) {
1067				rcu_read_unlock();
1068				put_page(page);
1069				head_skb = page_to_skb(vi, rq, xdp_page, offset,
1070						       len, PAGE_SIZE, false,
1071						       metasize,
1072						       headroom);
1073				return head_skb;
1074			}
1075			break;
1076		case XDP_TX:
1077			stats->xdp_tx++;
1078			xdpf = xdp_convert_buff_to_frame(&xdp);
1079			if (unlikely(!xdpf)) {
1080				if (unlikely(xdp_page != page))
1081					put_page(xdp_page);
1082				goto err_xdp;
1083			}
1084			err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
1085			if (unlikely(!err)) {
1086				xdp_return_frame_rx_napi(xdpf);
1087			} else if (unlikely(err < 0)) {
1088				trace_xdp_exception(vi->dev, xdp_prog, act);
1089				if (unlikely(xdp_page != page))
1090					put_page(xdp_page);
1091				goto err_xdp;
1092			}
1093			*xdp_xmit |= VIRTIO_XDP_TX;
1094			if (unlikely(xdp_page != page))
1095				put_page(page);
1096			rcu_read_unlock();
1097			goto xdp_xmit;
1098		case XDP_REDIRECT:
1099			stats->xdp_redirects++;
1100			err = xdp_do_redirect(dev, &xdp, xdp_prog);
1101			if (err) {
1102				if (unlikely(xdp_page != page))
1103					put_page(xdp_page);
1104				goto err_xdp;
1105			}
1106			*xdp_xmit |= VIRTIO_XDP_REDIR;
1107			if (unlikely(xdp_page != page))
1108				put_page(page);
1109			rcu_read_unlock();
1110			goto xdp_xmit;
1111		default:
1112			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
1113			fallthrough;
1114		case XDP_ABORTED:
1115			trace_xdp_exception(vi->dev, xdp_prog, act);
1116			fallthrough;
1117		case XDP_DROP:
1118			if (unlikely(xdp_page != page))
1119				__free_pages(xdp_page, 0);
1120			goto err_xdp;
1121		}
1122	}
1123	rcu_read_unlock();
1124
1125skip_xdp:
1126	head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
1127			       metasize, headroom);
 
 
 
 
 
 
1128	curr_skb = head_skb;
1129
1130	if (unlikely(!curr_skb))
1131		goto err_skb;
1132	while (--num_buf) {
1133		int num_skb_frags;
1134
1135		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1136		if (unlikely(!buf)) {
1137			pr_debug("%s: rx error: %d buffers out of %d missing\n",
1138				 dev->name, num_buf,
1139				 virtio16_to_cpu(vi->vdev,
1140						 hdr->num_buffers));
1141			dev->stats.rx_length_errors++;
1142			goto err_buf;
1143		}
1144
1145		stats->bytes += len;
1146		page = virt_to_head_page(buf);
1147
1148		truesize = mergeable_ctx_to_truesize(ctx);
1149		if (unlikely(len > truesize)) {
1150			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1151				 dev->name, len, (unsigned long)ctx);
1152			dev->stats.rx_length_errors++;
1153			goto err_skb;
1154		}
1155
1156		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
1157		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
1158			struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
1159
1160			if (unlikely(!nskb))
1161				goto err_skb;
1162			if (curr_skb == head_skb)
1163				skb_shinfo(curr_skb)->frag_list = nskb;
1164			else
1165				curr_skb->next = nskb;
1166			curr_skb = nskb;
1167			head_skb->truesize += nskb->truesize;
1168			num_skb_frags = 0;
1169		}
1170		if (curr_skb != head_skb) {
1171			head_skb->data_len += len;
1172			head_skb->len += len;
1173			head_skb->truesize += truesize;
1174		}
1175		offset = buf - page_address(page);
1176		if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1177			put_page(page);
1178			skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1179					     len, truesize);
1180		} else {
1181			skb_add_rx_frag(curr_skb, num_skb_frags, page,
1182					offset, len, truesize);
1183		}
1184	}
1185
1186	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1187	return head_skb;
1188
1189err_xdp:
1190	rcu_read_unlock();
1191	stats->xdp_drops++;
1192err_skb:
1193	put_page(page);
1194	while (num_buf-- > 1) {
1195		buf = virtqueue_get_buf(rq->vq, &len);
1196		if (unlikely(!buf)) {
1197			pr_debug("%s: rx error: %d buffers missing\n",
1198				 dev->name, num_buf);
1199			dev->stats.rx_length_errors++;
1200			break;
1201		}
1202		stats->bytes += len;
1203		page = virt_to_head_page(buf);
1204		put_page(page);
1205	}
1206err_buf:
1207	stats->drops++;
1208	dev_kfree_skb(head_skb);
1209xdp_xmit:
1210	return NULL;
1211}
1212
1213static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
1214				struct sk_buff *skb)
1215{
1216	enum pkt_hash_types rss_hash_type;
1217
1218	if (!hdr_hash || !skb)
1219		return;
1220
1221	switch (__le16_to_cpu(hdr_hash->hash_report)) {
1222	case VIRTIO_NET_HASH_REPORT_TCPv4:
1223	case VIRTIO_NET_HASH_REPORT_UDPv4:
1224	case VIRTIO_NET_HASH_REPORT_TCPv6:
1225	case VIRTIO_NET_HASH_REPORT_UDPv6:
1226	case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
1227	case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
1228		rss_hash_type = PKT_HASH_TYPE_L4;
1229		break;
1230	case VIRTIO_NET_HASH_REPORT_IPv4:
1231	case VIRTIO_NET_HASH_REPORT_IPv6:
1232	case VIRTIO_NET_HASH_REPORT_IPv6_EX:
1233		rss_hash_type = PKT_HASH_TYPE_L3;
1234		break;
1235	case VIRTIO_NET_HASH_REPORT_NONE:
1236	default:
1237		rss_hash_type = PKT_HASH_TYPE_NONE;
1238	}
1239	skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type);
1240}
1241
1242static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1243			void *buf, unsigned int len, void **ctx,
1244			unsigned int *xdp_xmit,
1245			struct virtnet_rq_stats *stats)
1246{
1247	struct net_device *dev = vi->dev;
1248	struct sk_buff *skb;
1249	struct virtio_net_hdr_mrg_rxbuf *hdr;
 
1250
1251	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1252		pr_debug("%s: short packet %i\n", dev->name, len);
1253		dev->stats.rx_length_errors++;
1254		if (vi->mergeable_rx_bufs) {
1255			put_page(virt_to_head_page(buf));
1256		} else if (vi->big_packets) {
1257			give_pages(rq, buf);
1258		} else {
1259			put_page(virt_to_head_page(buf));
1260		}
1261		return;
1262	}
1263
1264	if (vi->mergeable_rx_bufs)
1265		skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1266					stats);
1267	else if (vi->big_packets)
1268		skb = receive_big(dev, vi, rq, buf, len, stats);
1269	else
1270		skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1271
1272	if (unlikely(!skb))
1273		return;
1274
1275	hdr = skb_vnet_hdr(skb);
1276	if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
1277		virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
1278
1279	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1280		skb->ip_summed = CHECKSUM_UNNECESSARY;
1281
1282	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1283				  virtio_is_little_endian(vi->vdev))) {
1284		net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1285				     dev->name, hdr->hdr.gso_type,
1286				     hdr->hdr.gso_size);
1287		goto frame_err;
1288	}
1289
1290	skb_record_rx_queue(skb, vq2rxq(rq->vq));
1291	skb->protocol = eth_type_trans(skb, dev);
1292	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1293		 ntohs(skb->protocol), skb->len, skb->pkt_type);
1294
1295	napi_gro_receive(&rq->napi, skb);
1296	return;
1297
1298frame_err:
1299	dev->stats.rx_frame_errors++;
1300	dev_kfree_skb(skb);
 
1301}
1302
1303/* Unlike mergeable buffers, all buffers are allocated to the
1304 * same size, except for the headroom. For this reason we do
1305 * not need to use  mergeable_len_to_ctx here - it is enough
1306 * to store the headroom as the context ignoring the truesize.
1307 */
1308static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1309			     gfp_t gfp)
1310{
1311	struct page_frag *alloc_frag = &rq->alloc_frag;
1312	char *buf;
1313	unsigned int xdp_headroom = virtnet_get_headroom(vi);
1314	void *ctx = (void *)(unsigned long)xdp_headroom;
1315	int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1316	int err;
1317
1318	len = SKB_DATA_ALIGN(len) +
1319	      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1320	if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1321		return -ENOMEM;
1322
1323	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1324	get_page(alloc_frag->page);
1325	alloc_frag->offset += len;
1326	sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1327		    vi->hdr_len + GOOD_PACKET_LEN);
1328	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1329	if (err < 0)
1330		put_page(virt_to_head_page(buf));
1331	return err;
1332}
1333
1334static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1335			   gfp_t gfp)
1336{
1337	struct page *first, *list = NULL;
1338	char *p;
1339	int i, err, offset;
1340
1341	sg_init_table(rq->sg, vi->big_packets_num_skbfrags + 2);
1342
1343	/* page in rq->sg[vi->big_packets_num_skbfrags + 1] is list tail */
1344	for (i = vi->big_packets_num_skbfrags + 1; i > 1; --i) {
1345		first = get_a_page(rq, gfp);
1346		if (!first) {
1347			if (list)
1348				give_pages(rq, list);
1349			return -ENOMEM;
1350		}
1351		sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1352
1353		/* chain new page in list head to match sg */
1354		first->private = (unsigned long)list;
1355		list = first;
1356	}
1357
1358	first = get_a_page(rq, gfp);
1359	if (!first) {
1360		give_pages(rq, list);
1361		return -ENOMEM;
1362	}
1363	p = page_address(first);
1364
1365	/* rq->sg[0], rq->sg[1] share the same page */
1366	/* a separated rq->sg[0] for header - required in case !any_header_sg */
1367	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1368
1369	/* rq->sg[1] for data packet, from offset */
1370	offset = sizeof(struct padded_vnet_hdr);
1371	sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1372
1373	/* chain first in list head */
1374	first->private = (unsigned long)list;
1375	err = virtqueue_add_inbuf(rq->vq, rq->sg, vi->big_packets_num_skbfrags + 2,
1376				  first, gfp);
1377	if (err < 0)
1378		give_pages(rq, first);
1379
1380	return err;
1381}
1382
1383static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1384					  struct ewma_pkt_len *avg_pkt_len,
1385					  unsigned int room)
1386{
1387	struct virtnet_info *vi = rq->vq->vdev->priv;
1388	const size_t hdr_len = vi->hdr_len;
1389	unsigned int len;
1390
1391	if (room)
1392		return PAGE_SIZE - room;
1393
1394	len = hdr_len +	clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1395				rq->min_buf_len, PAGE_SIZE - hdr_len);
1396
1397	return ALIGN(len, L1_CACHE_BYTES);
1398}
1399
1400static int add_recvbuf_mergeable(struct virtnet_info *vi,
1401				 struct receive_queue *rq, gfp_t gfp)
1402{
1403	struct page_frag *alloc_frag = &rq->alloc_frag;
1404	unsigned int headroom = virtnet_get_headroom(vi);
1405	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1406	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1407	char *buf;
1408	void *ctx;
1409	int err;
1410	unsigned int len, hole;
1411
1412	/* Extra tailroom is needed to satisfy XDP's assumption. This
1413	 * means rx frags coalescing won't work, but consider we've
1414	 * disabled GSO for XDP, it won't be a big issue.
1415	 */
1416	len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1417	if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1418		return -ENOMEM;
1419
1420	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1421	buf += headroom; /* advance address leaving hole at front of pkt */
1422	get_page(alloc_frag->page);
1423	alloc_frag->offset += len + room;
1424	hole = alloc_frag->size - alloc_frag->offset;
1425	if (hole < len + room) {
1426		/* To avoid internal fragmentation, if there is very likely not
1427		 * enough space for another buffer, add the remaining space to
1428		 * the current buffer.
1429		 */
1430		len += hole;
1431		alloc_frag->offset += hole;
1432	}
1433
1434	sg_init_one(rq->sg, buf, len);
1435	ctx = mergeable_len_to_ctx(len, headroom);
1436	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1437	if (err < 0)
1438		put_page(virt_to_head_page(buf));
1439
1440	return err;
1441}
1442
1443/*
1444 * Returns false if we couldn't fill entirely (OOM).
1445 *
1446 * Normally run in the receive path, but can also be run from ndo_open
1447 * before we're receiving packets, or from refill_work which is
1448 * careful to disable receiving (using napi_disable).
1449 */
1450static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1451			  gfp_t gfp)
1452{
1453	int err;
1454	bool oom;
1455
1456	do {
1457		if (vi->mergeable_rx_bufs)
1458			err = add_recvbuf_mergeable(vi, rq, gfp);
1459		else if (vi->big_packets)
1460			err = add_recvbuf_big(vi, rq, gfp);
1461		else
1462			err = add_recvbuf_small(vi, rq, gfp);
1463
1464		oom = err == -ENOMEM;
1465		if (err)
1466			break;
1467	} while (rq->vq->num_free);
1468	if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1469		unsigned long flags;
1470
1471		flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1472		rq->stats.kicks++;
1473		u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1474	}
1475
1476	return !oom;
1477}
1478
1479static void skb_recv_done(struct virtqueue *rvq)
1480{
1481	struct virtnet_info *vi = rvq->vdev->priv;
1482	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1483
1484	virtqueue_napi_schedule(&rq->napi, rvq);
1485}
1486
1487static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1488{
1489	napi_enable(napi);
1490
1491	/* If all buffers were filled by other side before we napi_enabled, we
1492	 * won't get another interrupt, so process any outstanding packets now.
1493	 * Call local_bh_enable after to trigger softIRQ processing.
1494	 */
1495	local_bh_disable();
1496	virtqueue_napi_schedule(napi, vq);
1497	local_bh_enable();
1498}
1499
1500static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1501				   struct virtqueue *vq,
1502				   struct napi_struct *napi)
1503{
1504	if (!napi->weight)
1505		return;
1506
1507	/* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1508	 * enable the feature if this is likely affine with the transmit path.
1509	 */
1510	if (!vi->affinity_hint_set) {
1511		napi->weight = 0;
1512		return;
1513	}
1514
1515	return virtnet_napi_enable(vq, napi);
1516}
1517
1518static void virtnet_napi_tx_disable(struct napi_struct *napi)
1519{
1520	if (napi->weight)
1521		napi_disable(napi);
1522}
1523
1524static void refill_work(struct work_struct *work)
1525{
1526	struct virtnet_info *vi =
1527		container_of(work, struct virtnet_info, refill.work);
1528	bool still_empty;
1529	int i;
1530
1531	for (i = 0; i < vi->curr_queue_pairs; i++) {
1532		struct receive_queue *rq = &vi->rq[i];
1533
1534		napi_disable(&rq->napi);
1535		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1536		virtnet_napi_enable(rq->vq, &rq->napi);
1537
1538		/* In theory, this can happen: if we don't get any buffers in
1539		 * we will *never* try to fill again.
1540		 */
1541		if (still_empty)
1542			schedule_delayed_work(&vi->refill, HZ/2);
1543	}
1544}
1545
1546static int virtnet_receive(struct receive_queue *rq, int budget,
1547			   unsigned int *xdp_xmit)
1548{
1549	struct virtnet_info *vi = rq->vq->vdev->priv;
1550	struct virtnet_rq_stats stats = {};
1551	unsigned int len;
1552	void *buf;
1553	int i;
1554
1555	if (!vi->big_packets || vi->mergeable_rx_bufs) {
1556		void *ctx;
1557
1558		while (stats.packets < budget &&
1559		       (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1560			receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1561			stats.packets++;
1562		}
1563	} else {
1564		while (stats.packets < budget &&
1565		       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1566			receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1567			stats.packets++;
1568		}
1569	}
1570
1571	if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1572		if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
1573			spin_lock(&vi->refill_lock);
1574			if (vi->refill_enabled)
1575				schedule_delayed_work(&vi->refill, 0);
1576			spin_unlock(&vi->refill_lock);
1577		}
1578	}
1579
1580	u64_stats_update_begin(&rq->stats.syncp);
1581	for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1582		size_t offset = virtnet_rq_stats_desc[i].offset;
1583		u64 *item;
1584
1585		item = (u64 *)((u8 *)&rq->stats + offset);
1586		*item += *(u64 *)((u8 *)&stats + offset);
1587	}
1588	u64_stats_update_end(&rq->stats.syncp);
1589
1590	return stats.packets;
1591}
1592
1593static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
1594{
 
1595	unsigned int len;
1596	unsigned int packets = 0;
1597	unsigned int bytes = 0;
1598	void *ptr;
1599
1600	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1601		if (likely(!is_xdp_frame(ptr))) {
1602			struct sk_buff *skb = ptr;
1603
1604			pr_debug("Sent skb %p\n", skb);
 
1605
1606			bytes += skb->len;
1607			napi_consume_skb(skb, in_napi);
1608		} else {
1609			struct xdp_frame *frame = ptr_to_xdp(ptr);
1610
1611			bytes += frame->len;
1612			xdp_return_frame(frame);
1613		}
1614		packets++;
1615	}
1616
1617	/* Avoid overhead when no packets have been processed
1618	 * happens when called speculatively from start_xmit.
1619	 */
1620	if (!packets)
1621		return;
1622
1623	u64_stats_update_begin(&sq->stats.syncp);
1624	sq->stats.bytes += bytes;
1625	sq->stats.packets += packets;
1626	u64_stats_update_end(&sq->stats.syncp);
1627}
1628
1629static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
1630{
1631	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1632		return false;
1633	else if (q < vi->curr_queue_pairs)
1634		return true;
1635	else
1636		return false;
1637}
1638
1639static void virtnet_poll_cleantx(struct receive_queue *rq)
1640{
1641	struct virtnet_info *vi = rq->vq->vdev->priv;
1642	unsigned int index = vq2rxq(rq->vq);
1643	struct send_queue *sq = &vi->sq[index];
1644	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1645
1646	if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1647		return;
1648
1649	if (__netif_tx_trylock(txq)) {
1650		if (sq->reset) {
1651			__netif_tx_unlock(txq);
1652			return;
1653		}
1654
1655		do {
1656			virtqueue_disable_cb(sq->vq);
1657			free_old_xmit_skbs(sq, true);
1658		} while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1659
1660		if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1661			netif_tx_wake_queue(txq);
1662
1663		__netif_tx_unlock(txq);
1664	}
 
 
 
1665}
1666
1667static int virtnet_poll(struct napi_struct *napi, int budget)
1668{
1669	struct receive_queue *rq =
1670		container_of(napi, struct receive_queue, napi);
1671	struct virtnet_info *vi = rq->vq->vdev->priv;
1672	struct send_queue *sq;
1673	unsigned int received;
1674	unsigned int xdp_xmit = 0;
1675
1676	virtnet_poll_cleantx(rq);
1677
1678	received = virtnet_receive(rq, budget, &xdp_xmit);
1679
1680	if (xdp_xmit & VIRTIO_XDP_REDIR)
1681		xdp_do_flush();
1682
1683	/* Out of packets? */
1684	if (received < budget)
1685		virtqueue_napi_complete(napi, rq->vq, received);
1686
1687	if (xdp_xmit & VIRTIO_XDP_TX) {
1688		sq = virtnet_xdp_get_sq(vi);
1689		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1690			u64_stats_update_begin(&sq->stats.syncp);
1691			sq->stats.kicks++;
1692			u64_stats_update_end(&sq->stats.syncp);
1693		}
1694		virtnet_xdp_put_sq(vi, sq);
1695	}
1696
1697	return received;
1698}
1699
1700static int virtnet_open(struct net_device *dev)
1701{
1702	struct virtnet_info *vi = netdev_priv(dev);
1703	int i, err;
1704
1705	enable_delayed_refill(vi);
1706
1707	for (i = 0; i < vi->max_queue_pairs; i++) {
1708		if (i < vi->curr_queue_pairs)
1709			/* Make sure we have some buffers: if oom use wq. */
1710			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1711				schedule_delayed_work(&vi->refill, 0);
1712
1713		err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1714		if (err < 0)
1715			return err;
1716
1717		err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1718						 MEM_TYPE_PAGE_SHARED, NULL);
1719		if (err < 0) {
1720			xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1721			return err;
1722		}
1723
1724		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1725		virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1726	}
1727
1728	return 0;
1729}
1730
1731static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1732{
1733	struct send_queue *sq = container_of(napi, struct send_queue, napi);
1734	struct virtnet_info *vi = sq->vq->vdev->priv;
1735	unsigned int index = vq2txq(sq->vq);
1736	struct netdev_queue *txq;
1737	int opaque;
1738	bool done;
1739
1740	if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1741		/* We don't need to enable cb for XDP */
1742		napi_complete_done(napi, 0);
1743		return 0;
1744	}
1745
1746	txq = netdev_get_tx_queue(vi->dev, index);
1747	__netif_tx_lock(txq, raw_smp_processor_id());
1748	virtqueue_disable_cb(sq->vq);
1749	free_old_xmit_skbs(sq, true);
1750
1751	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1752		netif_tx_wake_queue(txq);
1753
1754	opaque = virtqueue_enable_cb_prepare(sq->vq);
1755
1756	done = napi_complete_done(napi, 0);
1757
1758	if (!done)
1759		virtqueue_disable_cb(sq->vq);
1760
1761	__netif_tx_unlock(txq);
1762
1763	if (done) {
1764		if (unlikely(virtqueue_poll(sq->vq, opaque))) {
1765			if (napi_schedule_prep(napi)) {
1766				__netif_tx_lock(txq, raw_smp_processor_id());
1767				virtqueue_disable_cb(sq->vq);
1768				__netif_tx_unlock(txq);
1769				__napi_schedule(napi);
1770			}
1771		}
1772	}
1773
1774	return 0;
1775}
1776
1777static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1778{
1779	struct virtio_net_hdr_mrg_rxbuf *hdr;
1780	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1781	struct virtnet_info *vi = sq->vq->vdev->priv;
1782	int num_sg;
1783	unsigned hdr_len = vi->hdr_len;
1784	bool can_push;
1785
1786	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1787
1788	can_push = vi->any_header_sg &&
1789		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1790		!skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1791	/* Even if we can, don't push here yet as this would skew
1792	 * csum_start offset below. */
1793	if (can_push)
1794		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1795	else
1796		hdr = skb_vnet_hdr(skb);
1797
1798	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1799				    virtio_is_little_endian(vi->vdev), false,
1800				    0))
1801		return -EPROTO;
1802
1803	if (vi->mergeable_rx_bufs)
1804		hdr->num_buffers = 0;
1805
1806	sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1807	if (can_push) {
1808		__skb_push(skb, hdr_len);
1809		num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1810		if (unlikely(num_sg < 0))
1811			return num_sg;
1812		/* Pull header back to avoid skew in tx bytes calculations. */
1813		__skb_pull(skb, hdr_len);
1814	} else {
1815		sg_set_buf(sq->sg, hdr, hdr_len);
1816		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1817		if (unlikely(num_sg < 0))
1818			return num_sg;
1819		num_sg++;
1820	}
1821	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1822}
1823
1824static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1825{
1826	struct virtnet_info *vi = netdev_priv(dev);
1827	int qnum = skb_get_queue_mapping(skb);
1828	struct send_queue *sq = &vi->sq[qnum];
1829	int err;
1830	struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1831	bool kick = !netdev_xmit_more();
1832	bool use_napi = sq->napi.weight;
1833
1834	/* Free up any pending old buffers before queueing new ones. */
1835	do {
1836		if (use_napi)
1837			virtqueue_disable_cb(sq->vq);
1838
1839		free_old_xmit_skbs(sq, false);
1840
1841	} while (use_napi && kick &&
1842	       unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1843
1844	/* timestamp packet in software */
1845	skb_tx_timestamp(skb);
1846
1847	/* Try to transmit */
1848	err = xmit_skb(sq, skb);
1849
1850	/* This should not happen! */
1851	if (unlikely(err)) {
1852		dev->stats.tx_fifo_errors++;
1853		if (net_ratelimit())
1854			dev_warn(&dev->dev,
1855				 "Unexpected TXQ (%d) queue failure: %d\n",
1856				 qnum, err);
1857		dev->stats.tx_dropped++;
1858		dev_kfree_skb_any(skb);
1859		return NETDEV_TX_OK;
1860	}
1861
1862	/* Don't wait up for transmitted skbs to be freed. */
1863	if (!use_napi) {
1864		skb_orphan(skb);
1865		nf_reset_ct(skb);
1866	}
1867
1868	/* If running out of space, stop queue to avoid getting packets that we
1869	 * are then unable to transmit.
1870	 * An alternative would be to force queuing layer to requeue the skb by
1871	 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1872	 * returned in a normal path of operation: it means that driver is not
1873	 * maintaining the TX queue stop/start state properly, and causes
1874	 * the stack to do a non-trivial amount of useless work.
1875	 * Since most packets only take 1 or 2 ring slots, stopping the queue
1876	 * early means 16 slots are typically wasted.
1877	 */
1878	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1879		netif_stop_subqueue(dev, qnum);
1880		if (use_napi) {
1881			if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
1882				virtqueue_napi_schedule(&sq->napi, sq->vq);
1883		} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1884			/* More just got used, free them then recheck. */
1885			free_old_xmit_skbs(sq, false);
1886			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1887				netif_start_subqueue(dev, qnum);
1888				virtqueue_disable_cb(sq->vq);
1889			}
1890		}
1891	}
1892
1893	if (kick || netif_xmit_stopped(txq)) {
1894		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1895			u64_stats_update_begin(&sq->stats.syncp);
1896			sq->stats.kicks++;
1897			u64_stats_update_end(&sq->stats.syncp);
1898		}
1899	}
1900
1901	return NETDEV_TX_OK;
1902}
1903
1904static int virtnet_rx_resize(struct virtnet_info *vi,
1905			     struct receive_queue *rq, u32 ring_num)
1906{
1907	bool running = netif_running(vi->dev);
1908	int err, qindex;
1909
1910	qindex = rq - vi->rq;
1911
1912	if (running)
1913		napi_disable(&rq->napi);
1914
1915	err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
1916	if (err)
1917		netdev_err(vi->dev, "resize rx fail: rx queue index: %d err: %d\n", qindex, err);
1918
1919	if (!try_fill_recv(vi, rq, GFP_KERNEL))
1920		schedule_delayed_work(&vi->refill, 0);
1921
1922	if (running)
1923		virtnet_napi_enable(rq->vq, &rq->napi);
1924	return err;
1925}
1926
1927static int virtnet_tx_resize(struct virtnet_info *vi,
1928			     struct send_queue *sq, u32 ring_num)
1929{
1930	bool running = netif_running(vi->dev);
1931	struct netdev_queue *txq;
1932	int err, qindex;
1933
1934	qindex = sq - vi->sq;
1935
1936	if (running)
1937		virtnet_napi_tx_disable(&sq->napi);
1938
1939	txq = netdev_get_tx_queue(vi->dev, qindex);
1940
1941	/* 1. wait all ximt complete
1942	 * 2. fix the race of netif_stop_subqueue() vs netif_start_subqueue()
1943	 */
1944	__netif_tx_lock_bh(txq);
1945
1946	/* Prevent rx poll from accessing sq. */
1947	sq->reset = true;
1948
1949	/* Prevent the upper layer from trying to send packets. */
1950	netif_stop_subqueue(vi->dev, qindex);
1951
1952	__netif_tx_unlock_bh(txq);
1953
1954	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
1955	if (err)
1956		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
1957
1958	__netif_tx_lock_bh(txq);
1959	sq->reset = false;
1960	netif_tx_wake_queue(txq);
1961	__netif_tx_unlock_bh(txq);
1962
1963	if (running)
1964		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
1965	return err;
1966}
1967
1968/*
1969 * Send command via the control virtqueue and check status.  Commands
1970 * supported by the hypervisor, as indicated by feature bits, should
1971 * never fail unless improperly formatted.
1972 */
1973static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1974				 struct scatterlist *out)
1975{
1976	struct scatterlist *sgs[4], hdr, stat;
1977	unsigned out_num = 0, tmp;
1978	int ret;
1979
1980	/* Caller should know better */
1981	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1982
1983	vi->ctrl->status = ~0;
1984	vi->ctrl->hdr.class = class;
1985	vi->ctrl->hdr.cmd = cmd;
1986	/* Add header */
1987	sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1988	sgs[out_num++] = &hdr;
1989
1990	if (out)
1991		sgs[out_num++] = out;
1992
1993	/* Add return status. */
1994	sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1995	sgs[out_num] = &stat;
1996
1997	BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1998	ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1999	if (ret < 0) {
2000		dev_warn(&vi->vdev->dev,
2001			 "Failed to add sgs for command vq: %d\n.", ret);
2002		return false;
2003	}
2004
2005	if (unlikely(!virtqueue_kick(vi->cvq)))
2006		return vi->ctrl->status == VIRTIO_NET_OK;
2007
2008	/* Spin for a response, the kick causes an ioport write, trapping
2009	 * into the hypervisor, so the request should be handled immediately.
2010	 */
2011	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
2012	       !virtqueue_is_broken(vi->cvq))
2013		cpu_relax();
2014
2015	return vi->ctrl->status == VIRTIO_NET_OK;
2016}
2017
2018static int virtnet_set_mac_address(struct net_device *dev, void *p)
2019{
2020	struct virtnet_info *vi = netdev_priv(dev);
2021	struct virtio_device *vdev = vi->vdev;
2022	int ret;
2023	struct sockaddr *addr;
2024	struct scatterlist sg;
2025
2026	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2027		return -EOPNOTSUPP;
2028
2029	addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
2030	if (!addr)
2031		return -ENOMEM;
2032
2033	ret = eth_prepare_mac_addr_change(dev, addr);
2034	if (ret)
2035		goto out;
2036
2037	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
2038		sg_init_one(&sg, addr->sa_data, dev->addr_len);
2039		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2040					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
2041			dev_warn(&vdev->dev,
2042				 "Failed to set mac address by vq command.\n");
2043			ret = -EINVAL;
2044			goto out;
2045		}
2046	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
2047		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
2048		unsigned int i;
2049
2050		/* Naturally, this has an atomicity problem. */
2051		for (i = 0; i < dev->addr_len; i++)
2052			virtio_cwrite8(vdev,
2053				       offsetof(struct virtio_net_config, mac) +
2054				       i, addr->sa_data[i]);
2055	}
2056
2057	eth_commit_mac_addr_change(dev, p);
2058	ret = 0;
2059
2060out:
2061	kfree(addr);
2062	return ret;
2063}
2064
2065static void virtnet_stats(struct net_device *dev,
2066			  struct rtnl_link_stats64 *tot)
2067{
2068	struct virtnet_info *vi = netdev_priv(dev);
2069	unsigned int start;
2070	int i;
2071
2072	for (i = 0; i < vi->max_queue_pairs; i++) {
2073		u64 tpackets, tbytes, terrors, rpackets, rbytes, rdrops;
2074		struct receive_queue *rq = &vi->rq[i];
2075		struct send_queue *sq = &vi->sq[i];
2076
2077		do {
2078			start = u64_stats_fetch_begin(&sq->stats.syncp);
2079			tpackets = sq->stats.packets;
2080			tbytes   = sq->stats.bytes;
2081			terrors  = sq->stats.tx_timeouts;
2082		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2083
2084		do {
2085			start = u64_stats_fetch_begin(&rq->stats.syncp);
2086			rpackets = rq->stats.packets;
2087			rbytes   = rq->stats.bytes;
2088			rdrops   = rq->stats.drops;
2089		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2090
2091		tot->rx_packets += rpackets;
2092		tot->tx_packets += tpackets;
2093		tot->rx_bytes   += rbytes;
2094		tot->tx_bytes   += tbytes;
2095		tot->rx_dropped += rdrops;
2096		tot->tx_errors  += terrors;
2097	}
2098
2099	tot->tx_dropped = dev->stats.tx_dropped;
2100	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 
2101	tot->rx_length_errors = dev->stats.rx_length_errors;
2102	tot->rx_frame_errors = dev->stats.rx_frame_errors;
2103}
2104
 
 
 
 
 
 
 
 
 
 
 
2105static void virtnet_ack_link_announce(struct virtnet_info *vi)
2106{
2107	rtnl_lock();
2108	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
2109				  VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
2110		dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
2111	rtnl_unlock();
2112}
2113
2114static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2115{
2116	struct scatterlist sg;
2117	struct net_device *dev = vi->dev;
2118
2119	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
2120		return 0;
2121
2122	vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
2123	sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
2124
2125	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2126				  VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
2127		dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
2128			 queue_pairs);
2129		return -EINVAL;
2130	} else {
2131		vi->curr_queue_pairs = queue_pairs;
2132		/* virtnet_open() will refill when device is going to up. */
2133		if (dev->flags & IFF_UP)
2134			schedule_delayed_work(&vi->refill, 0);
2135	}
2136
2137	return 0;
2138}
2139
2140static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2141{
2142	int err;
2143
2144	rtnl_lock();
2145	err = _virtnet_set_queues(vi, queue_pairs);
2146	rtnl_unlock();
2147	return err;
2148}
2149
2150static int virtnet_close(struct net_device *dev)
2151{
2152	struct virtnet_info *vi = netdev_priv(dev);
2153	int i;
2154
2155	/* Make sure NAPI doesn't schedule refill work */
2156	disable_delayed_refill(vi);
2157	/* Make sure refill_work doesn't re-enable napi! */
2158	cancel_delayed_work_sync(&vi->refill);
2159
2160	for (i = 0; i < vi->max_queue_pairs; i++) {
 
2161		napi_disable(&vi->rq[i].napi);
2162		xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
2163		virtnet_napi_tx_disable(&vi->sq[i].napi);
2164	}
2165
2166	return 0;
2167}
2168
2169static void virtnet_set_rx_mode(struct net_device *dev)
2170{
2171	struct virtnet_info *vi = netdev_priv(dev);
2172	struct scatterlist sg[2];
2173	struct virtio_net_ctrl_mac *mac_data;
2174	struct netdev_hw_addr *ha;
2175	int uc_count;
2176	int mc_count;
2177	void *buf;
2178	int i;
2179
2180	/* We can't dynamically set ndo_set_rx_mode, so return gracefully */
2181	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
2182		return;
2183
2184	vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
2185	vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
2186
2187	sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
2188
2189	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2190				  VIRTIO_NET_CTRL_RX_PROMISC, sg))
2191		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
2192			 vi->ctrl->promisc ? "en" : "dis");
2193
2194	sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
2195
2196	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2197				  VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
2198		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
2199			 vi->ctrl->allmulti ? "en" : "dis");
2200
2201	uc_count = netdev_uc_count(dev);
2202	mc_count = netdev_mc_count(dev);
2203	/* MAC filter - use one buffer for both lists */
2204	buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
2205		      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
2206	mac_data = buf;
2207	if (!buf)
2208		return;
2209
2210	sg_init_table(sg, 2);
2211
2212	/* Store the unicast list and count in the front of the buffer */
2213	mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
2214	i = 0;
2215	netdev_for_each_uc_addr(ha, dev)
2216		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2217
2218	sg_set_buf(&sg[0], mac_data,
2219		   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
2220
2221	/* multicast list and count fill the end */
2222	mac_data = (void *)&mac_data->macs[uc_count][0];
2223
2224	mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
2225	i = 0;
2226	netdev_for_each_mc_addr(ha, dev)
2227		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2228
2229	sg_set_buf(&sg[1], mac_data,
2230		   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
2231
2232	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2233				  VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
2234		dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
2235
2236	kfree(buf);
2237}
2238
2239static int virtnet_vlan_rx_add_vid(struct net_device *dev,
2240				   __be16 proto, u16 vid)
2241{
2242	struct virtnet_info *vi = netdev_priv(dev);
2243	struct scatterlist sg;
2244
2245	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2246	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2247
2248	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2249				  VIRTIO_NET_CTRL_VLAN_ADD, &sg))
2250		dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
2251	return 0;
2252}
2253
2254static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
2255				    __be16 proto, u16 vid)
2256{
2257	struct virtnet_info *vi = netdev_priv(dev);
2258	struct scatterlist sg;
2259
2260	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2261	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2262
2263	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2264				  VIRTIO_NET_CTRL_VLAN_DEL, &sg))
2265		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
2266	return 0;
2267}
2268
2269static void virtnet_clean_affinity(struct virtnet_info *vi)
2270{
2271	int i;
2272
2273	if (vi->affinity_hint_set) {
2274		for (i = 0; i < vi->max_queue_pairs; i++) {
2275			virtqueue_set_affinity(vi->rq[i].vq, NULL);
2276			virtqueue_set_affinity(vi->sq[i].vq, NULL);
2277		}
2278
2279		vi->affinity_hint_set = false;
2280	}
2281}
2282
2283static void virtnet_set_affinity(struct virtnet_info *vi)
2284{
2285	cpumask_var_t mask;
2286	int stragglers;
2287	int group_size;
2288	int i, j, cpu;
2289	int num_cpu;
2290	int stride;
2291
2292	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
2293		virtnet_clean_affinity(vi);
 
 
 
 
 
2294		return;
2295	}
2296
2297	num_cpu = num_online_cpus();
2298	stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
2299	stragglers = num_cpu >= vi->curr_queue_pairs ?
2300			num_cpu % vi->curr_queue_pairs :
2301			0;
2302	cpu = cpumask_first(cpu_online_mask);
2303
2304	for (i = 0; i < vi->curr_queue_pairs; i++) {
2305		group_size = stride + (i < stragglers ? 1 : 0);
2306
2307		for (j = 0; j < group_size; j++) {
2308			cpumask_set_cpu(cpu, mask);
2309			cpu = cpumask_next_wrap(cpu, cpu_online_mask,
2310						nr_cpu_ids, false);
2311		}
2312		virtqueue_set_affinity(vi->rq[i].vq, mask);
2313		virtqueue_set_affinity(vi->sq[i].vq, mask);
2314		__netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, XPS_CPUS);
2315		cpumask_clear(mask);
2316	}
2317
2318	vi->affinity_hint_set = true;
2319	free_cpumask_var(mask);
2320}
2321
2322static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
2323{
2324	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2325						   node);
2326	virtnet_set_affinity(vi);
2327	return 0;
2328}
2329
2330static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2331{
2332	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2333						   node_dead);
2334	virtnet_set_affinity(vi);
2335	return 0;
2336}
2337
2338static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2339{
2340	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2341						   node);
2342
2343	virtnet_clean_affinity(vi);
2344	return 0;
2345}
2346
2347static enum cpuhp_state virtionet_online;
2348
2349static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2350{
2351	int ret;
2352
2353	ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2354	if (ret)
2355		return ret;
2356	ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2357					       &vi->node_dead);
2358	if (!ret)
2359		return ret;
2360	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2361	return ret;
2362}
2363
2364static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2365{
2366	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2367	cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2368					    &vi->node_dead);
2369}
2370
2371static void virtnet_get_ringparam(struct net_device *dev,
2372				  struct ethtool_ringparam *ring,
2373				  struct kernel_ethtool_ringparam *kernel_ring,
2374				  struct netlink_ext_ack *extack)
2375{
2376	struct virtnet_info *vi = netdev_priv(dev);
2377
2378	ring->rx_max_pending = vi->rq[0].vq->num_max;
2379	ring->tx_max_pending = vi->sq[0].vq->num_max;
2380	ring->rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2381	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2382}
2383
2384static int virtnet_set_ringparam(struct net_device *dev,
2385				 struct ethtool_ringparam *ring,
2386				 struct kernel_ethtool_ringparam *kernel_ring,
2387				 struct netlink_ext_ack *extack)
2388{
2389	struct virtnet_info *vi = netdev_priv(dev);
2390	u32 rx_pending, tx_pending;
2391	struct receive_queue *rq;
2392	struct send_queue *sq;
2393	int i, err;
2394
2395	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
2396		return -EINVAL;
2397
2398	rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2399	tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2400
2401	if (ring->rx_pending == rx_pending &&
2402	    ring->tx_pending == tx_pending)
2403		return 0;
2404
2405	if (ring->rx_pending > vi->rq[0].vq->num_max)
2406		return -EINVAL;
2407
2408	if (ring->tx_pending > vi->sq[0].vq->num_max)
2409		return -EINVAL;
2410
2411	for (i = 0; i < vi->max_queue_pairs; i++) {
2412		rq = vi->rq + i;
2413		sq = vi->sq + i;
2414
2415		if (ring->tx_pending != tx_pending) {
2416			err = virtnet_tx_resize(vi, sq, ring->tx_pending);
2417			if (err)
2418				return err;
2419		}
2420
2421		if (ring->rx_pending != rx_pending) {
2422			err = virtnet_rx_resize(vi, rq, ring->rx_pending);
2423			if (err)
2424				return err;
2425		}
2426	}
2427
2428	return 0;
2429}
2430
2431static bool virtnet_commit_rss_command(struct virtnet_info *vi)
2432{
2433	struct net_device *dev = vi->dev;
2434	struct scatterlist sgs[4];
2435	unsigned int sg_buf_size;
2436
2437	/* prepare sgs */
2438	sg_init_table(sgs, 4);
2439
2440	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, indirection_table);
2441	sg_set_buf(&sgs[0], &vi->ctrl->rss, sg_buf_size);
2442
2443	sg_buf_size = sizeof(uint16_t) * (vi->ctrl->rss.indirection_table_mask + 1);
2444	sg_set_buf(&sgs[1], vi->ctrl->rss.indirection_table, sg_buf_size);
2445
2446	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)
2447			- offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
2448	sg_set_buf(&sgs[2], &vi->ctrl->rss.max_tx_vq, sg_buf_size);
2449
2450	sg_buf_size = vi->rss_key_size;
2451	sg_set_buf(&sgs[3], vi->ctrl->rss.key, sg_buf_size);
2452
2453	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2454				  vi->has_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG
2455				  : VIRTIO_NET_CTRL_MQ_HASH_CONFIG, sgs)) {
2456		dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
2457		return false;
2458	}
2459	return true;
2460}
2461
2462static void virtnet_init_default_rss(struct virtnet_info *vi)
2463{
2464	u32 indir_val = 0;
2465	int i = 0;
2466
2467	vi->ctrl->rss.hash_types = vi->rss_hash_types_supported;
2468	vi->rss_hash_types_saved = vi->rss_hash_types_supported;
2469	vi->ctrl->rss.indirection_table_mask = vi->rss_indir_table_size
2470						? vi->rss_indir_table_size - 1 : 0;
2471	vi->ctrl->rss.unclassified_queue = 0;
2472
2473	for (; i < vi->rss_indir_table_size; ++i) {
2474		indir_val = ethtool_rxfh_indir_default(i, vi->curr_queue_pairs);
2475		vi->ctrl->rss.indirection_table[i] = indir_val;
2476	}
2477
2478	vi->ctrl->rss.max_tx_vq = vi->curr_queue_pairs;
2479	vi->ctrl->rss.hash_key_length = vi->rss_key_size;
2480
2481	netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
2482}
2483
2484static void virtnet_get_hashflow(const struct virtnet_info *vi, struct ethtool_rxnfc *info)
2485{
2486	info->data = 0;
2487	switch (info->flow_type) {
2488	case TCP_V4_FLOW:
2489		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
2490			info->data = RXH_IP_SRC | RXH_IP_DST |
2491						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2492		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2493			info->data = RXH_IP_SRC | RXH_IP_DST;
2494		}
2495		break;
2496	case TCP_V6_FLOW:
2497		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
2498			info->data = RXH_IP_SRC | RXH_IP_DST |
2499						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2500		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2501			info->data = RXH_IP_SRC | RXH_IP_DST;
2502		}
2503		break;
2504	case UDP_V4_FLOW:
2505		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
2506			info->data = RXH_IP_SRC | RXH_IP_DST |
2507						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2508		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2509			info->data = RXH_IP_SRC | RXH_IP_DST;
2510		}
2511		break;
2512	case UDP_V6_FLOW:
2513		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
2514			info->data = RXH_IP_SRC | RXH_IP_DST |
2515						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2516		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2517			info->data = RXH_IP_SRC | RXH_IP_DST;
2518		}
2519		break;
2520	case IPV4_FLOW:
2521		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4)
2522			info->data = RXH_IP_SRC | RXH_IP_DST;
2523
2524		break;
2525	case IPV6_FLOW:
2526		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6)
2527			info->data = RXH_IP_SRC | RXH_IP_DST;
2528
2529		break;
2530	default:
2531		info->data = 0;
2532		break;
2533	}
2534}
2535
2536static bool virtnet_set_hashflow(struct virtnet_info *vi, struct ethtool_rxnfc *info)
2537{
2538	u32 new_hashtypes = vi->rss_hash_types_saved;
2539	bool is_disable = info->data & RXH_DISCARD;
2540	bool is_l4 = info->data == (RXH_IP_SRC | RXH_IP_DST | RXH_L4_B_0_1 | RXH_L4_B_2_3);
2541
2542	/* supports only 'sd', 'sdfn' and 'r' */
2543	if (!((info->data == (RXH_IP_SRC | RXH_IP_DST)) | is_l4 | is_disable))
2544		return false;
2545
2546	switch (info->flow_type) {
2547	case TCP_V4_FLOW:
2548		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_TCPv4);
2549		if (!is_disable)
2550			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2551				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv4 : 0);
2552		break;
2553	case UDP_V4_FLOW:
2554		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_UDPv4);
2555		if (!is_disable)
2556			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2557				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv4 : 0);
2558		break;
2559	case IPV4_FLOW:
2560		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2561		if (!is_disable)
2562			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2563		break;
2564	case TCP_V6_FLOW:
2565		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_TCPv6);
2566		if (!is_disable)
2567			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2568				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv6 : 0);
2569		break;
2570	case UDP_V6_FLOW:
2571		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_UDPv6);
2572		if (!is_disable)
2573			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2574				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv6 : 0);
2575		break;
2576	case IPV6_FLOW:
2577		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2578		if (!is_disable)
2579			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2580		break;
2581	default:
2582		/* unsupported flow */
2583		return false;
2584	}
2585
2586	/* if unsupported hashtype was set */
2587	if (new_hashtypes != (new_hashtypes & vi->rss_hash_types_supported))
2588		return false;
2589
2590	if (new_hashtypes != vi->rss_hash_types_saved) {
2591		vi->rss_hash_types_saved = new_hashtypes;
2592		vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
2593		if (vi->dev->features & NETIF_F_RXHASH)
2594			return virtnet_commit_rss_command(vi);
2595	}
2596
2597	return true;
2598}
2599
2600static void virtnet_get_drvinfo(struct net_device *dev,
2601				struct ethtool_drvinfo *info)
2602{
2603	struct virtnet_info *vi = netdev_priv(dev);
2604	struct virtio_device *vdev = vi->vdev;
2605
2606	strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2607	strscpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2608	strscpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2609
2610}
2611
2612/* TODO: Eliminate OOO packets during switching */
2613static int virtnet_set_channels(struct net_device *dev,
2614				struct ethtool_channels *channels)
2615{
2616	struct virtnet_info *vi = netdev_priv(dev);
2617	u16 queue_pairs = channels->combined_count;
2618	int err;
2619
2620	/* We don't support separate rx/tx channels.
2621	 * We don't allow setting 'other' channels.
2622	 */
2623	if (channels->rx_count || channels->tx_count || channels->other_count)
2624		return -EINVAL;
2625
2626	if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2627		return -EINVAL;
2628
2629	/* For now we don't support modifying channels while XDP is loaded
2630	 * also when XDP is loaded all RX queues have XDP programs so we only
2631	 * need to check a single RX queue.
2632	 */
2633	if (vi->rq[0].xdp_prog)
2634		return -EINVAL;
2635
2636	cpus_read_lock();
2637	err = _virtnet_set_queues(vi, queue_pairs);
2638	if (err) {
2639		cpus_read_unlock();
2640		goto err;
 
 
2641	}
2642	virtnet_set_affinity(vi);
2643	cpus_read_unlock();
2644
2645	netif_set_real_num_tx_queues(dev, queue_pairs);
2646	netif_set_real_num_rx_queues(dev, queue_pairs);
2647 err:
2648	return err;
2649}
2650
2651static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2652{
2653	struct virtnet_info *vi = netdev_priv(dev);
 
2654	unsigned int i, j;
2655	u8 *p = data;
2656
2657	switch (stringset) {
2658	case ETH_SS_STATS:
2659		for (i = 0; i < vi->curr_queue_pairs; i++) {
2660			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
2661				ethtool_sprintf(&p, "rx_queue_%u_%s", i,
2662						virtnet_rq_stats_desc[j].desc);
 
 
2663		}
2664
2665		for (i = 0; i < vi->curr_queue_pairs; i++) {
2666			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
2667				ethtool_sprintf(&p, "tx_queue_%u_%s", i,
2668						virtnet_sq_stats_desc[j].desc);
 
 
2669		}
2670		break;
2671	}
2672}
2673
2674static int virtnet_get_sset_count(struct net_device *dev, int sset)
2675{
2676	struct virtnet_info *vi = netdev_priv(dev);
2677
2678	switch (sset) {
2679	case ETH_SS_STATS:
2680		return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2681					       VIRTNET_SQ_STATS_LEN);
2682	default:
2683		return -EOPNOTSUPP;
2684	}
2685}
2686
2687static void virtnet_get_ethtool_stats(struct net_device *dev,
2688				      struct ethtool_stats *stats, u64 *data)
2689{
2690	struct virtnet_info *vi = netdev_priv(dev);
2691	unsigned int idx = 0, start, i, j;
2692	const u8 *stats_base;
2693	size_t offset;
2694
2695	for (i = 0; i < vi->curr_queue_pairs; i++) {
2696		struct receive_queue *rq = &vi->rq[i];
2697
2698		stats_base = (u8 *)&rq->stats;
2699		do {
2700			start = u64_stats_fetch_begin(&rq->stats.syncp);
2701			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2702				offset = virtnet_rq_stats_desc[j].offset;
2703				data[idx + j] = *(u64 *)(stats_base + offset);
2704			}
2705		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2706		idx += VIRTNET_RQ_STATS_LEN;
2707	}
2708
2709	for (i = 0; i < vi->curr_queue_pairs; i++) {
2710		struct send_queue *sq = &vi->sq[i];
2711
2712		stats_base = (u8 *)&sq->stats;
2713		do {
2714			start = u64_stats_fetch_begin(&sq->stats.syncp);
2715			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2716				offset = virtnet_sq_stats_desc[j].offset;
2717				data[idx + j] = *(u64 *)(stats_base + offset);
2718			}
2719		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2720		idx += VIRTNET_SQ_STATS_LEN;
2721	}
2722}
2723
2724static void virtnet_get_channels(struct net_device *dev,
2725				 struct ethtool_channels *channels)
2726{
2727	struct virtnet_info *vi = netdev_priv(dev);
2728
2729	channels->combined_count = vi->curr_queue_pairs;
2730	channels->max_combined = vi->max_queue_pairs;
2731	channels->max_other = 0;
2732	channels->rx_count = 0;
2733	channels->tx_count = 0;
2734	channels->other_count = 0;
2735}
2736
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2737static int virtnet_set_link_ksettings(struct net_device *dev,
2738				      const struct ethtool_link_ksettings *cmd)
2739{
2740	struct virtnet_info *vi = netdev_priv(dev);
 
 
 
 
 
 
 
 
 
 
2741
2742	return ethtool_virtdev_set_link_ksettings(dev, cmd,
2743						  &vi->speed, &vi->duplex);
2744}
2745
2746static int virtnet_get_link_ksettings(struct net_device *dev,
2747				      struct ethtool_link_ksettings *cmd)
2748{
2749	struct virtnet_info *vi = netdev_priv(dev);
2750
2751	cmd->base.speed = vi->speed;
2752	cmd->base.duplex = vi->duplex;
2753	cmd->base.port = PORT_OTHER;
2754
2755	return 0;
2756}
2757
2758static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
2759				       struct ethtool_coalesce *ec)
2760{
2761	struct scatterlist sgs_tx, sgs_rx;
2762	struct virtio_net_ctrl_coal_tx coal_tx;
2763	struct virtio_net_ctrl_coal_rx coal_rx;
2764
2765	coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
2766	coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
2767	sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
2768
2769	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2770				  VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
2771				  &sgs_tx))
2772		return -EINVAL;
2773
2774	/* Save parameters */
2775	vi->tx_usecs = ec->tx_coalesce_usecs;
2776	vi->tx_max_packets = ec->tx_max_coalesced_frames;
2777
2778	coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
2779	coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
2780	sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
2781
2782	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2783				  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
2784				  &sgs_rx))
2785		return -EINVAL;
2786
2787	/* Save parameters */
2788	vi->rx_usecs = ec->rx_coalesce_usecs;
2789	vi->rx_max_packets = ec->rx_max_coalesced_frames;
2790
2791	return 0;
2792}
2793
2794static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
2795{
2796	/* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
2797	 * feature is negotiated.
2798	 */
2799	if (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs)
2800		return -EOPNOTSUPP;
2801
2802	if (ec->tx_max_coalesced_frames > 1 ||
2803	    ec->rx_max_coalesced_frames != 1)
2804		return -EINVAL;
2805
2806	return 0;
2807}
2808
2809static int virtnet_set_coalesce(struct net_device *dev,
2810				struct ethtool_coalesce *ec,
2811				struct kernel_ethtool_coalesce *kernel_coal,
2812				struct netlink_ext_ack *extack)
2813{
2814	struct virtnet_info *vi = netdev_priv(dev);
2815	int ret, i, napi_weight;
2816	bool update_napi = false;
2817
2818	/* Can't change NAPI weight if the link is up */
2819	napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2820	if (napi_weight ^ vi->sq[0].napi.weight) {
2821		if (dev->flags & IFF_UP)
2822			return -EBUSY;
2823		else
2824			update_napi = true;
2825	}
2826
2827	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL))
2828		ret = virtnet_send_notf_coal_cmds(vi, ec);
2829	else
2830		ret = virtnet_coal_params_supported(ec);
2831
2832	if (ret)
2833		return ret;
2834
2835	if (update_napi) {
2836		for (i = 0; i < vi->max_queue_pairs; i++)
2837			vi->sq[i].napi.weight = napi_weight;
2838	}
2839
2840	return ret;
2841}
2842
2843static int virtnet_get_coalesce(struct net_device *dev,
2844				struct ethtool_coalesce *ec,
2845				struct kernel_ethtool_coalesce *kernel_coal,
2846				struct netlink_ext_ack *extack)
2847{
2848	struct virtnet_info *vi = netdev_priv(dev);
2849
2850	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
2851		ec->rx_coalesce_usecs = vi->rx_usecs;
2852		ec->tx_coalesce_usecs = vi->tx_usecs;
2853		ec->tx_max_coalesced_frames = vi->tx_max_packets;
2854		ec->rx_max_coalesced_frames = vi->rx_max_packets;
2855	} else {
2856		ec->rx_max_coalesced_frames = 1;
2857
2858		if (vi->sq[0].napi.weight)
2859			ec->tx_max_coalesced_frames = 1;
2860	}
2861
2862	return 0;
2863}
2864
2865static void virtnet_init_settings(struct net_device *dev)
2866{
2867	struct virtnet_info *vi = netdev_priv(dev);
2868
2869	vi->speed = SPEED_UNKNOWN;
2870	vi->duplex = DUPLEX_UNKNOWN;
2871}
2872
2873static void virtnet_update_settings(struct virtnet_info *vi)
2874{
2875	u32 speed;
2876	u8 duplex;
2877
2878	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2879		return;
2880
2881	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
2882
2883	if (ethtool_validate_speed(speed))
2884		vi->speed = speed;
2885
2886	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
2887
2888	if (ethtool_validate_duplex(duplex))
2889		vi->duplex = duplex;
2890}
2891
2892static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
2893{
2894	return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
2895}
2896
2897static u32 virtnet_get_rxfh_indir_size(struct net_device *dev)
2898{
2899	return ((struct virtnet_info *)netdev_priv(dev))->rss_indir_table_size;
2900}
2901
2902static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
2903{
2904	struct virtnet_info *vi = netdev_priv(dev);
2905	int i;
2906
2907	if (indir) {
2908		for (i = 0; i < vi->rss_indir_table_size; ++i)
2909			indir[i] = vi->ctrl->rss.indirection_table[i];
2910	}
2911
2912	if (key)
2913		memcpy(key, vi->ctrl->rss.key, vi->rss_key_size);
2914
2915	if (hfunc)
2916		*hfunc = ETH_RSS_HASH_TOP;
2917
2918	return 0;
2919}
2920
2921static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc)
2922{
2923	struct virtnet_info *vi = netdev_priv(dev);
2924	int i;
2925
2926	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
2927		return -EOPNOTSUPP;
2928
2929	if (indir) {
2930		for (i = 0; i < vi->rss_indir_table_size; ++i)
2931			vi->ctrl->rss.indirection_table[i] = indir[i];
2932	}
2933	if (key)
2934		memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
2935
2936	virtnet_commit_rss_command(vi);
2937
2938	return 0;
2939}
2940
2941static int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *rule_locs)
2942{
2943	struct virtnet_info *vi = netdev_priv(dev);
2944	int rc = 0;
2945
2946	switch (info->cmd) {
2947	case ETHTOOL_GRXRINGS:
2948		info->data = vi->curr_queue_pairs;
2949		break;
2950	case ETHTOOL_GRXFH:
2951		virtnet_get_hashflow(vi, info);
2952		break;
2953	default:
2954		rc = -EOPNOTSUPP;
2955	}
2956
2957	return rc;
2958}
2959
2960static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info)
2961{
2962	struct virtnet_info *vi = netdev_priv(dev);
2963	int rc = 0;
2964
2965	switch (info->cmd) {
2966	case ETHTOOL_SRXFH:
2967		if (!virtnet_set_hashflow(vi, info))
2968			rc = -EINVAL;
2969
2970		break;
2971	default:
2972		rc = -EOPNOTSUPP;
2973	}
2974
2975	return rc;
2976}
2977
2978static const struct ethtool_ops virtnet_ethtool_ops = {
2979	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
2980		ETHTOOL_COALESCE_USECS,
2981	.get_drvinfo = virtnet_get_drvinfo,
2982	.get_link = ethtool_op_get_link,
2983	.get_ringparam = virtnet_get_ringparam,
2984	.set_ringparam = virtnet_set_ringparam,
2985	.get_strings = virtnet_get_strings,
2986	.get_sset_count = virtnet_get_sset_count,
2987	.get_ethtool_stats = virtnet_get_ethtool_stats,
2988	.set_channels = virtnet_set_channels,
2989	.get_channels = virtnet_get_channels,
2990	.get_ts_info = ethtool_op_get_ts_info,
2991	.get_link_ksettings = virtnet_get_link_ksettings,
2992	.set_link_ksettings = virtnet_set_link_ksettings,
2993	.set_coalesce = virtnet_set_coalesce,
2994	.get_coalesce = virtnet_get_coalesce,
2995	.get_rxfh_key_size = virtnet_get_rxfh_key_size,
2996	.get_rxfh_indir_size = virtnet_get_rxfh_indir_size,
2997	.get_rxfh = virtnet_get_rxfh,
2998	.set_rxfh = virtnet_set_rxfh,
2999	.get_rxnfc = virtnet_get_rxnfc,
3000	.set_rxnfc = virtnet_set_rxnfc,
3001};
3002
3003static void virtnet_freeze_down(struct virtio_device *vdev)
3004{
3005	struct virtnet_info *vi = vdev->priv;
 
3006
3007	/* Make sure no work handler is accessing the device */
3008	flush_work(&vi->config_work);
3009
3010	netif_tx_lock_bh(vi->dev);
3011	netif_device_detach(vi->dev);
3012	netif_tx_unlock_bh(vi->dev);
3013	if (netif_running(vi->dev))
3014		virtnet_close(vi->dev);
 
 
 
 
 
 
3015}
3016
3017static int init_vqs(struct virtnet_info *vi);
3018
3019static int virtnet_restore_up(struct virtio_device *vdev)
3020{
3021	struct virtnet_info *vi = vdev->priv;
3022	int err;
3023
3024	err = init_vqs(vi);
3025	if (err)
3026		return err;
3027
3028	virtio_device_ready(vdev);
3029
3030	enable_delayed_refill(vi);
 
 
 
3031
3032	if (netif_running(vi->dev)) {
3033		err = virtnet_open(vi->dev);
3034		if (err)
3035			return err;
 
3036	}
3037
3038	netif_tx_lock_bh(vi->dev);
3039	netif_device_attach(vi->dev);
3040	netif_tx_unlock_bh(vi->dev);
3041	return err;
3042}
3043
3044static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
3045{
3046	struct scatterlist sg;
3047	vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
3048
3049	sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
3050
3051	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
3052				  VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
3053		dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
3054		return -EINVAL;
3055	}
3056
3057	return 0;
3058}
3059
3060static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
3061{
3062	u64 offloads = 0;
3063
3064	if (!vi->guest_offloads)
3065		return 0;
3066
 
 
 
3067	return virtnet_set_guest_offloads(vi, offloads);
3068}
3069
3070static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
3071{
3072	u64 offloads = vi->guest_offloads;
3073
3074	if (!vi->guest_offloads)
3075		return 0;
 
 
3076
3077	return virtnet_set_guest_offloads(vi, offloads);
3078}
3079
3080static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
3081			   struct netlink_ext_ack *extack)
3082{
3083	unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
3084	struct virtnet_info *vi = netdev_priv(dev);
3085	struct bpf_prog *old_prog;
3086	u16 xdp_qp = 0, curr_qp;
3087	int i, err;
3088
3089	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
3090	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3091	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3092	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3093		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3094		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM) ||
3095		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) ||
3096		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6))) {
3097		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
3098		return -EOPNOTSUPP;
3099	}
3100
3101	if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
3102		NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
3103		return -EINVAL;
3104	}
3105
3106	if (dev->mtu > max_sz) {
3107		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
3108		netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
3109		return -EINVAL;
3110	}
3111
3112	curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
3113	if (prog)
3114		xdp_qp = nr_cpu_ids;
3115
3116	/* XDP requires extra queues for XDP_TX */
3117	if (curr_qp + xdp_qp > vi->max_queue_pairs) {
3118		netdev_warn_once(dev, "XDP request %i queues but max is %i. XDP_TX and XDP_REDIRECT will operate in a slower locked tx mode.\n",
3119				 curr_qp + xdp_qp, vi->max_queue_pairs);
3120		xdp_qp = 0;
 
3121	}
3122
3123	old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
3124	if (!prog && !old_prog)
3125		return 0;
3126
3127	if (prog)
3128		bpf_prog_add(prog, vi->max_queue_pairs - 1);
3129
3130	/* Make sure NAPI is not using any XDP TX queues for RX. */
3131	if (netif_running(dev)) {
3132		for (i = 0; i < vi->max_queue_pairs; i++) {
3133			napi_disable(&vi->rq[i].napi);
3134			virtnet_napi_tx_disable(&vi->sq[i].napi);
3135		}
3136	}
3137
3138	if (!prog) {
3139		for (i = 0; i < vi->max_queue_pairs; i++) {
3140			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3141			if (i == 0)
3142				virtnet_restore_guest_offloads(vi);
3143		}
3144		synchronize_net();
3145	}
3146
 
3147	err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
3148	if (err)
3149		goto err;
3150	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
3151	vi->xdp_queue_pairs = xdp_qp;
3152
3153	if (prog) {
3154		vi->xdp_enabled = true;
3155		for (i = 0; i < vi->max_queue_pairs; i++) {
3156			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3157			if (i == 0 && !old_prog)
3158				virtnet_clear_guest_offloads(vi);
 
 
3159		}
3160	} else {
3161		vi->xdp_enabled = false;
3162	}
3163
3164	for (i = 0; i < vi->max_queue_pairs; i++) {
3165		if (old_prog)
3166			bpf_prog_put(old_prog);
3167		if (netif_running(dev)) {
3168			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3169			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3170					       &vi->sq[i].napi);
3171		}
3172	}
3173
3174	return 0;
3175
3176err:
3177	if (!prog) {
3178		virtnet_clear_guest_offloads(vi);
3179		for (i = 0; i < vi->max_queue_pairs; i++)
3180			rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
3181	}
3182
3183	if (netif_running(dev)) {
3184		for (i = 0; i < vi->max_queue_pairs; i++) {
3185			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3186			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3187					       &vi->sq[i].napi);
3188		}
3189	}
3190	if (prog)
3191		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
3192	return err;
3193}
3194
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3195static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
3196{
3197	switch (xdp->command) {
3198	case XDP_SETUP_PROG:
3199		return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
 
 
 
 
3200	default:
3201		return -EINVAL;
3202	}
3203}
3204
3205static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
3206				      size_t len)
3207{
3208	struct virtnet_info *vi = netdev_priv(dev);
3209	int ret;
3210
3211	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
3212		return -EOPNOTSUPP;
3213
3214	ret = snprintf(buf, len, "sby");
3215	if (ret >= len)
3216		return -EOPNOTSUPP;
3217
3218	return 0;
3219}
3220
3221static int virtnet_set_features(struct net_device *dev,
3222				netdev_features_t features)
3223{
3224	struct virtnet_info *vi = netdev_priv(dev);
3225	u64 offloads;
3226	int err;
3227
3228	if ((dev->features ^ features) & NETIF_F_GRO_HW) {
3229		if (vi->xdp_enabled)
3230			return -EBUSY;
3231
3232		if (features & NETIF_F_GRO_HW)
3233			offloads = vi->guest_offloads_capable;
3234		else
3235			offloads = vi->guest_offloads_capable &
3236				   ~GUEST_OFFLOAD_GRO_HW_MASK;
3237
3238		err = virtnet_set_guest_offloads(vi, offloads);
3239		if (err)
3240			return err;
3241		vi->guest_offloads = offloads;
3242	}
3243
3244	if ((dev->features ^ features) & NETIF_F_RXHASH) {
3245		if (features & NETIF_F_RXHASH)
3246			vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
3247		else
3248			vi->ctrl->rss.hash_types = VIRTIO_NET_HASH_REPORT_NONE;
3249
3250		if (!virtnet_commit_rss_command(vi))
3251			return -EINVAL;
3252	}
3253
3254	return 0;
3255}
3256
3257static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
3258{
3259	struct virtnet_info *priv = netdev_priv(dev);
3260	struct send_queue *sq = &priv->sq[txqueue];
3261	struct netdev_queue *txq = netdev_get_tx_queue(dev, txqueue);
3262
3263	u64_stats_update_begin(&sq->stats.syncp);
3264	sq->stats.tx_timeouts++;
3265	u64_stats_update_end(&sq->stats.syncp);
3266
3267	netdev_err(dev, "TX timeout on queue: %u, sq: %s, vq: 0x%x, name: %s, %u usecs ago\n",
3268		   txqueue, sq->name, sq->vq->index, sq->vq->name,
3269		   jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start)));
3270}
3271
3272static const struct net_device_ops virtnet_netdev = {
3273	.ndo_open            = virtnet_open,
3274	.ndo_stop   	     = virtnet_close,
3275	.ndo_start_xmit      = start_xmit,
3276	.ndo_validate_addr   = eth_validate_addr,
3277	.ndo_set_mac_address = virtnet_set_mac_address,
3278	.ndo_set_rx_mode     = virtnet_set_rx_mode,
3279	.ndo_get_stats64     = virtnet_stats,
3280	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
3281	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
 
 
 
3282	.ndo_bpf		= virtnet_xdp,
3283	.ndo_xdp_xmit		= virtnet_xdp_xmit,
 
3284	.ndo_features_check	= passthru_features_check,
3285	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
3286	.ndo_set_features	= virtnet_set_features,
3287	.ndo_tx_timeout		= virtnet_tx_timeout,
3288};
3289
3290static void virtnet_config_changed_work(struct work_struct *work)
3291{
3292	struct virtnet_info *vi =
3293		container_of(work, struct virtnet_info, config_work);
3294	u16 v;
3295
3296	if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
3297				 struct virtio_net_config, status, &v) < 0)
3298		return;
3299
3300	if (v & VIRTIO_NET_S_ANNOUNCE) {
3301		netdev_notify_peers(vi->dev);
3302		virtnet_ack_link_announce(vi);
3303	}
3304
3305	/* Ignore unknown (future) status bits */
3306	v &= VIRTIO_NET_S_LINK_UP;
3307
3308	if (vi->status == v)
3309		return;
3310
3311	vi->status = v;
3312
3313	if (vi->status & VIRTIO_NET_S_LINK_UP) {
3314		virtnet_update_settings(vi);
3315		netif_carrier_on(vi->dev);
3316		netif_tx_wake_all_queues(vi->dev);
3317	} else {
3318		netif_carrier_off(vi->dev);
3319		netif_tx_stop_all_queues(vi->dev);
3320	}
3321}
3322
3323static void virtnet_config_changed(struct virtio_device *vdev)
3324{
3325	struct virtnet_info *vi = vdev->priv;
3326
3327	schedule_work(&vi->config_work);
3328}
3329
3330static void virtnet_free_queues(struct virtnet_info *vi)
3331{
3332	int i;
3333
3334	for (i = 0; i < vi->max_queue_pairs; i++) {
3335		__netif_napi_del(&vi->rq[i].napi);
3336		__netif_napi_del(&vi->sq[i].napi);
 
3337	}
3338
3339	/* We called __netif_napi_del(),
3340	 * we need to respect an RCU grace period before freeing vi->rq
3341	 */
3342	synchronize_net();
3343
3344	kfree(vi->rq);
3345	kfree(vi->sq);
3346	kfree(vi->ctrl);
3347}
3348
3349static void _free_receive_bufs(struct virtnet_info *vi)
3350{
3351	struct bpf_prog *old_prog;
3352	int i;
3353
3354	for (i = 0; i < vi->max_queue_pairs; i++) {
3355		while (vi->rq[i].pages)
3356			__free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
3357
3358		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
3359		RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
3360		if (old_prog)
3361			bpf_prog_put(old_prog);
3362	}
3363}
3364
3365static void free_receive_bufs(struct virtnet_info *vi)
3366{
3367	rtnl_lock();
3368	_free_receive_bufs(vi);
3369	rtnl_unlock();
3370}
3371
3372static void free_receive_page_frags(struct virtnet_info *vi)
3373{
3374	int i;
3375	for (i = 0; i < vi->max_queue_pairs; i++)
3376		if (vi->rq[i].alloc_frag.page)
3377			put_page(vi->rq[i].alloc_frag.page);
3378}
3379
3380static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
3381{
3382	if (!is_xdp_frame(buf))
3383		dev_kfree_skb(buf);
 
 
3384	else
3385		xdp_return_frame(ptr_to_xdp(buf));
3386}
3387
3388static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
3389{
3390	struct virtnet_info *vi = vq->vdev->priv;
3391	int i = vq2rxq(vq);
3392
3393	if (vi->mergeable_rx_bufs)
3394		put_page(virt_to_head_page(buf));
3395	else if (vi->big_packets)
3396		give_pages(&vi->rq[i], buf);
3397	else
3398		put_page(virt_to_head_page(buf));
3399}
3400
3401static void free_unused_bufs(struct virtnet_info *vi)
3402{
3403	void *buf;
3404	int i;
3405
3406	for (i = 0; i < vi->max_queue_pairs; i++) {
3407		struct virtqueue *vq = vi->sq[i].vq;
3408		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3409			virtnet_sq_free_unused_buf(vq, buf);
 
 
 
 
3410	}
3411
3412	for (i = 0; i < vi->max_queue_pairs; i++) {
3413		struct virtqueue *vq = vi->rq[i].vq;
3414		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3415			virtnet_rq_free_unused_buf(vq, buf);
 
 
 
 
 
 
 
 
3416	}
3417}
3418
3419static void virtnet_del_vqs(struct virtnet_info *vi)
3420{
3421	struct virtio_device *vdev = vi->vdev;
3422
3423	virtnet_clean_affinity(vi);
3424
3425	vdev->config->del_vqs(vdev);
3426
3427	virtnet_free_queues(vi);
3428}
3429
3430/* How large should a single buffer be so a queue full of these can fit at
3431 * least one full packet?
3432 * Logic below assumes the mergeable buffer header is used.
3433 */
3434static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
3435{
3436	const unsigned int hdr_len = vi->hdr_len;
3437	unsigned int rq_size = virtqueue_get_vring_size(vq);
3438	unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
3439	unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
3440	unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
3441
3442	return max(max(min_buf_len, hdr_len) - hdr_len,
3443		   (unsigned int)GOOD_PACKET_LEN);
3444}
3445
3446static int virtnet_find_vqs(struct virtnet_info *vi)
3447{
3448	vq_callback_t **callbacks;
3449	struct virtqueue **vqs;
3450	int ret = -ENOMEM;
3451	int i, total_vqs;
3452	const char **names;
3453	bool *ctx;
3454
3455	/* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
3456	 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
3457	 * possible control vq.
3458	 */
3459	total_vqs = vi->max_queue_pairs * 2 +
3460		    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
3461
3462	/* Allocate space for find_vqs parameters */
3463	vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
3464	if (!vqs)
3465		goto err_vq;
3466	callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
3467	if (!callbacks)
3468		goto err_callback;
3469	names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
3470	if (!names)
3471		goto err_names;
3472	if (!vi->big_packets || vi->mergeable_rx_bufs) {
3473		ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
3474		if (!ctx)
3475			goto err_ctx;
3476	} else {
3477		ctx = NULL;
3478	}
3479
3480	/* Parameters for control virtqueue, if any */
3481	if (vi->has_cvq) {
3482		callbacks[total_vqs - 1] = NULL;
3483		names[total_vqs - 1] = "control";
3484	}
3485
3486	/* Allocate/initialize parameters for send/receive virtqueues */
3487	for (i = 0; i < vi->max_queue_pairs; i++) {
3488		callbacks[rxq2vq(i)] = skb_recv_done;
3489		callbacks[txq2vq(i)] = skb_xmit_done;
3490		sprintf(vi->rq[i].name, "input.%d", i);
3491		sprintf(vi->sq[i].name, "output.%d", i);
3492		names[rxq2vq(i)] = vi->rq[i].name;
3493		names[txq2vq(i)] = vi->sq[i].name;
3494		if (ctx)
3495			ctx[rxq2vq(i)] = true;
3496	}
3497
3498	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
3499				  names, ctx, NULL);
3500	if (ret)
3501		goto err_find;
3502
3503	if (vi->has_cvq) {
3504		vi->cvq = vqs[total_vqs - 1];
3505		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
3506			vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
3507	}
3508
3509	for (i = 0; i < vi->max_queue_pairs; i++) {
3510		vi->rq[i].vq = vqs[rxq2vq(i)];
3511		vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
3512		vi->sq[i].vq = vqs[txq2vq(i)];
3513	}
3514
3515	/* run here: ret == 0. */
 
 
 
3516
 
3517
3518err_find:
3519	kfree(ctx);
3520err_ctx:
3521	kfree(names);
3522err_names:
3523	kfree(callbacks);
3524err_callback:
3525	kfree(vqs);
3526err_vq:
3527	return ret;
3528}
3529
3530static int virtnet_alloc_queues(struct virtnet_info *vi)
3531{
3532	int i;
3533
3534	if (vi->has_cvq) {
3535		vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
3536		if (!vi->ctrl)
3537			goto err_ctrl;
3538	} else {
3539		vi->ctrl = NULL;
3540	}
3541	vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
3542	if (!vi->sq)
3543		goto err_sq;
3544	vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
3545	if (!vi->rq)
3546		goto err_rq;
3547
3548	INIT_DELAYED_WORK(&vi->refill, refill_work);
3549	for (i = 0; i < vi->max_queue_pairs; i++) {
3550		vi->rq[i].pages = NULL;
3551		netif_napi_add_weight(vi->dev, &vi->rq[i].napi, virtnet_poll,
3552				      napi_weight);
3553		netif_napi_add_tx_weight(vi->dev, &vi->sq[i].napi,
3554					 virtnet_poll_tx,
3555					 napi_tx ? napi_weight : 0);
3556
3557		sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
3558		ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
3559		sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
3560
3561		u64_stats_init(&vi->rq[i].stats.syncp);
3562		u64_stats_init(&vi->sq[i].stats.syncp);
3563	}
3564
3565	return 0;
3566
3567err_rq:
3568	kfree(vi->sq);
3569err_sq:
3570	kfree(vi->ctrl);
3571err_ctrl:
3572	return -ENOMEM;
3573}
3574
3575static int init_vqs(struct virtnet_info *vi)
3576{
3577	int ret;
3578
3579	/* Allocate send & receive queues */
3580	ret = virtnet_alloc_queues(vi);
3581	if (ret)
3582		goto err;
3583
3584	ret = virtnet_find_vqs(vi);
3585	if (ret)
3586		goto err_free;
3587
3588	cpus_read_lock();
3589	virtnet_set_affinity(vi);
3590	cpus_read_unlock();
3591
3592	return 0;
3593
3594err_free:
3595	virtnet_free_queues(vi);
3596err:
3597	return ret;
3598}
3599
3600#ifdef CONFIG_SYSFS
3601static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
3602		char *buf)
3603{
3604	struct virtnet_info *vi = netdev_priv(queue->dev);
3605	unsigned int queue_index = get_netdev_rx_queue_index(queue);
3606	unsigned int headroom = virtnet_get_headroom(vi);
3607	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
3608	struct ewma_pkt_len *avg;
3609
3610	BUG_ON(queue_index >= vi->max_queue_pairs);
3611	avg = &vi->rq[queue_index].mrg_avg_pkt_len;
3612	return sprintf(buf, "%u\n",
3613		       get_mergeable_buf_len(&vi->rq[queue_index], avg,
3614				       SKB_DATA_ALIGN(headroom + tailroom)));
3615}
3616
3617static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
3618	__ATTR_RO(mergeable_rx_buffer_size);
3619
3620static struct attribute *virtio_net_mrg_rx_attrs[] = {
3621	&mergeable_rx_buffer_size_attribute.attr,
3622	NULL
3623};
3624
3625static const struct attribute_group virtio_net_mrg_rx_group = {
3626	.name = "virtio_net",
3627	.attrs = virtio_net_mrg_rx_attrs
3628};
3629#endif
3630
3631static bool virtnet_fail_on_feature(struct virtio_device *vdev,
3632				    unsigned int fbit,
3633				    const char *fname, const char *dname)
3634{
3635	if (!virtio_has_feature(vdev, fbit))
3636		return false;
3637
3638	dev_err(&vdev->dev, "device advertises feature %s but not %s",
3639		fname, dname);
3640
3641	return true;
3642}
3643
3644#define VIRTNET_FAIL_ON(vdev, fbit, dbit)			\
3645	virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
3646
3647static bool virtnet_validate_features(struct virtio_device *vdev)
3648{
3649	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
3650	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
3651			     "VIRTIO_NET_F_CTRL_VQ") ||
3652	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
3653			     "VIRTIO_NET_F_CTRL_VQ") ||
3654	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
3655			     "VIRTIO_NET_F_CTRL_VQ") ||
3656	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
3657	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
3658			     "VIRTIO_NET_F_CTRL_VQ") ||
3659	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS,
3660			     "VIRTIO_NET_F_CTRL_VQ") ||
3661	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT,
3662			     "VIRTIO_NET_F_CTRL_VQ") ||
3663	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_NOTF_COAL,
3664			     "VIRTIO_NET_F_CTRL_VQ"))) {
3665		return false;
3666	}
3667
3668	return true;
3669}
3670
3671#define MIN_MTU ETH_MIN_MTU
3672#define MAX_MTU ETH_MAX_MTU
3673
3674static int virtnet_validate(struct virtio_device *vdev)
3675{
3676	if (!vdev->config->get) {
3677		dev_err(&vdev->dev, "%s failure: config access disabled\n",
3678			__func__);
3679		return -EINVAL;
3680	}
3681
3682	if (!virtnet_validate_features(vdev))
3683		return -EINVAL;
3684
3685	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3686		int mtu = virtio_cread16(vdev,
3687					 offsetof(struct virtio_net_config,
3688						  mtu));
3689		if (mtu < MIN_MTU)
3690			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
3691	}
3692
3693	return 0;
3694}
3695
3696static bool virtnet_check_guest_gso(const struct virtnet_info *vi)
3697{
3698	return virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3699		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3700		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3701		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3702		(virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) &&
3703		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6));
3704}
3705
3706static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu)
3707{
3708	bool guest_gso = virtnet_check_guest_gso(vi);
3709
3710	/* If device can receive ANY guest GSO packets, regardless of mtu,
3711	 * allocate packets of maximum size, otherwise limit it to only
3712	 * mtu size worth only.
3713	 */
3714	if (mtu > ETH_DATA_LEN || guest_gso) {
3715		vi->big_packets = true;
3716		vi->big_packets_num_skbfrags = guest_gso ? MAX_SKB_FRAGS : DIV_ROUND_UP(mtu, PAGE_SIZE);
3717	}
3718}
3719
3720static int virtnet_probe(struct virtio_device *vdev)
3721{
3722	int i, err = -ENOMEM;
3723	struct net_device *dev;
3724	struct virtnet_info *vi;
3725	u16 max_queue_pairs;
3726	int mtu = 0;
3727
3728	/* Find if host supports multiqueue/rss virtio_net device */
3729	max_queue_pairs = 1;
3730	if (virtio_has_feature(vdev, VIRTIO_NET_F_MQ) || virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3731		max_queue_pairs =
3732		     virtio_cread16(vdev, offsetof(struct virtio_net_config, max_virtqueue_pairs));
3733
3734	/* We need at least 2 queue's */
3735	if (max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3736	    max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3737	    !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3738		max_queue_pairs = 1;
3739
3740	/* Allocate ourselves a network device with room for our info */
3741	dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3742	if (!dev)
3743		return -ENOMEM;
3744
3745	/* Set up network device as normal. */
3746	dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE |
3747			   IFF_TX_SKB_NO_LINEAR;
3748	dev->netdev_ops = &virtnet_netdev;
3749	dev->features = NETIF_F_HIGHDMA;
3750
3751	dev->ethtool_ops = &virtnet_ethtool_ops;
3752	SET_NETDEV_DEV(dev, &vdev->dev);
3753
3754	/* Do we support "hardware" checksums? */
3755	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3756		/* This opens up the world of extra features. */
3757		dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3758		if (csum)
3759			dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3760
3761		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3762			dev->hw_features |= NETIF_F_TSO
3763				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
3764		}
3765		/* Individual feature bits: what can host handle? */
3766		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3767			dev->hw_features |= NETIF_F_TSO;
3768		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3769			dev->hw_features |= NETIF_F_TSO6;
3770		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3771			dev->hw_features |= NETIF_F_TSO_ECN;
3772		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
3773			dev->hw_features |= NETIF_F_GSO_UDP_L4;
3774
3775		dev->features |= NETIF_F_GSO_ROBUST;
3776
3777		if (gso)
3778			dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3779		/* (!csum && gso) case will be fixed by register_netdev() */
3780	}
3781	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3782		dev->features |= NETIF_F_RXCSUM;
3783	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3784	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3785		dev->features |= NETIF_F_GRO_HW;
3786	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3787		dev->hw_features |= NETIF_F_GRO_HW;
3788
3789	dev->vlan_features = dev->features;
3790
3791	/* MTU range: 68 - 65535 */
3792	dev->min_mtu = MIN_MTU;
3793	dev->max_mtu = MAX_MTU;
3794
3795	/* Configuration may specify what MAC to use.  Otherwise random. */
3796	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
3797		u8 addr[ETH_ALEN];
3798
3799		virtio_cread_bytes(vdev,
3800				   offsetof(struct virtio_net_config, mac),
3801				   addr, ETH_ALEN);
3802		eth_hw_addr_set(dev, addr);
3803	} else {
3804		eth_hw_addr_random(dev);
3805	}
3806
3807	/* Set up our device-specific information */
3808	vi = netdev_priv(dev);
3809	vi->dev = dev;
3810	vi->vdev = vdev;
3811	vdev->priv = vi;
3812
3813	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3814	spin_lock_init(&vi->refill_lock);
 
 
 
 
 
 
3815
3816	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
3817		vi->mergeable_rx_bufs = true;
3818
3819	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
3820		vi->rx_usecs = 0;
3821		vi->tx_usecs = 0;
3822		vi->tx_max_packets = 0;
3823		vi->rx_max_packets = 0;
3824	}
3825
3826	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
3827		vi->has_rss_hash_report = true;
3828
3829	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3830		vi->has_rss = true;
3831
3832	if (vi->has_rss || vi->has_rss_hash_report) {
3833		vi->rss_indir_table_size =
3834			virtio_cread16(vdev, offsetof(struct virtio_net_config,
3835				rss_max_indirection_table_length));
3836		vi->rss_key_size =
3837			virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
3838
3839		vi->rss_hash_types_supported =
3840		    virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
3841		vi->rss_hash_types_supported &=
3842				~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
3843				  VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
3844				  VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
3845
3846		dev->hw_features |= NETIF_F_RXHASH;
3847	}
3848
3849	if (vi->has_rss_hash_report)
3850		vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash);
3851	else if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
3852		 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3853		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
3854	else
3855		vi->hdr_len = sizeof(struct virtio_net_hdr);
3856
3857	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
3858	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3859		vi->any_header_sg = true;
3860
3861	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3862		vi->has_cvq = true;
3863
3864	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3865		mtu = virtio_cread16(vdev,
3866				     offsetof(struct virtio_net_config,
3867					      mtu));
3868		if (mtu < dev->min_mtu) {
3869			/* Should never trigger: MTU was previously validated
3870			 * in virtnet_validate.
3871			 */
3872			dev_err(&vdev->dev,
3873				"device MTU appears to have changed it is now %d < %d",
3874				mtu, dev->min_mtu);
3875			err = -EINVAL;
3876			goto free;
3877		}
3878
3879		dev->mtu = mtu;
3880		dev->max_mtu = mtu;
 
 
 
 
3881	}
3882
3883	virtnet_set_big_packets(vi, mtu);
3884
3885	if (vi->any_header_sg)
3886		dev->needed_headroom = vi->hdr_len;
3887
3888	/* Enable multiqueue by default */
3889	if (num_online_cpus() >= max_queue_pairs)
3890		vi->curr_queue_pairs = max_queue_pairs;
3891	else
3892		vi->curr_queue_pairs = num_online_cpus();
3893	vi->max_queue_pairs = max_queue_pairs;
3894
3895	/* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3896	err = init_vqs(vi);
3897	if (err)
3898		goto free;
3899
3900#ifdef CONFIG_SYSFS
3901	if (vi->mergeable_rx_bufs)
3902		dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3903#endif
3904	netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3905	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3906
3907	virtnet_init_settings(dev);
3908
3909	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3910		vi->failover = net_failover_create(vi->dev);
3911		if (IS_ERR(vi->failover)) {
3912			err = PTR_ERR(vi->failover);
3913			goto free_vqs;
3914		}
3915	}
3916
3917	if (vi->has_rss || vi->has_rss_hash_report)
3918		virtnet_init_default_rss(vi);
3919
3920	/* serialize netdev register + virtio_device_ready() with ndo_open() */
3921	rtnl_lock();
3922
3923	err = register_netdevice(dev);
3924	if (err) {
3925		pr_debug("virtio_net: registering device failed\n");
3926		rtnl_unlock();
3927		goto free_failover;
3928	}
3929
3930	virtio_device_ready(vdev);
3931
3932	rtnl_unlock();
3933
3934	err = virtnet_cpu_notif_add(vi);
3935	if (err) {
3936		pr_debug("virtio_net: registering cpu notifier failed\n");
3937		goto free_unregister_netdev;
3938	}
3939
3940	virtnet_set_queues(vi, vi->curr_queue_pairs);
3941
3942	/* Assume link up if device can't report link status,
3943	   otherwise get link status from config. */
3944	netif_carrier_off(dev);
3945	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3946		schedule_work(&vi->config_work);
3947	} else {
3948		vi->status = VIRTIO_NET_S_LINK_UP;
3949		virtnet_update_settings(vi);
3950		netif_carrier_on(dev);
3951	}
3952
3953	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3954		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3955			set_bit(guest_offloads[i], &vi->guest_offloads);
3956	vi->guest_offloads_capable = vi->guest_offloads;
3957
3958	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3959		 dev->name, max_queue_pairs);
3960
3961	return 0;
3962
3963free_unregister_netdev:
 
 
3964	unregister_netdev(dev);
3965free_failover:
3966	net_failover_destroy(vi->failover);
3967free_vqs:
3968	virtio_reset_device(vdev);
3969	cancel_delayed_work_sync(&vi->refill);
3970	free_receive_page_frags(vi);
3971	virtnet_del_vqs(vi);
3972free:
3973	free_netdev(dev);
3974	return err;
3975}
3976
3977static void remove_vq_common(struct virtnet_info *vi)
3978{
3979	virtio_reset_device(vi->vdev);
3980
3981	/* Free unused buffers in both send and recv, if any. */
3982	free_unused_bufs(vi);
3983
3984	free_receive_bufs(vi);
3985
3986	free_receive_page_frags(vi);
3987
3988	virtnet_del_vqs(vi);
3989}
3990
3991static void virtnet_remove(struct virtio_device *vdev)
3992{
3993	struct virtnet_info *vi = vdev->priv;
3994
3995	virtnet_cpu_notif_remove(vi);
3996
3997	/* Make sure no work handler is accessing the device. */
3998	flush_work(&vi->config_work);
3999
4000	unregister_netdev(vi->dev);
4001
4002	net_failover_destroy(vi->failover);
4003
4004	remove_vq_common(vi);
4005
4006	free_netdev(vi->dev);
4007}
4008
4009static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
4010{
4011	struct virtnet_info *vi = vdev->priv;
4012
4013	virtnet_cpu_notif_remove(vi);
4014	virtnet_freeze_down(vdev);
4015	remove_vq_common(vi);
4016
4017	return 0;
4018}
4019
4020static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
4021{
4022	struct virtnet_info *vi = vdev->priv;
4023	int err;
4024
4025	err = virtnet_restore_up(vdev);
4026	if (err)
4027		return err;
4028	virtnet_set_queues(vi, vi->curr_queue_pairs);
4029
4030	err = virtnet_cpu_notif_add(vi);
4031	if (err) {
4032		virtnet_freeze_down(vdev);
4033		remove_vq_common(vi);
4034		return err;
4035	}
4036
4037	return 0;
4038}
4039
4040static struct virtio_device_id id_table[] = {
4041	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
4042	{ 0 },
4043};
4044
4045#define VIRTNET_FEATURES \
4046	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
4047	VIRTIO_NET_F_MAC, \
4048	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
4049	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
4050	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
4051	VIRTIO_NET_F_HOST_USO, VIRTIO_NET_F_GUEST_USO4, VIRTIO_NET_F_GUEST_USO6, \
4052	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
4053	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
4054	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
4055	VIRTIO_NET_F_CTRL_MAC_ADDR, \
4056	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
4057	VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \
4058	VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_NOTF_COAL
4059
4060static unsigned int features[] = {
4061	VIRTNET_FEATURES,
4062};
4063
4064static unsigned int features_legacy[] = {
4065	VIRTNET_FEATURES,
4066	VIRTIO_NET_F_GSO,
4067	VIRTIO_F_ANY_LAYOUT,
4068};
4069
4070static struct virtio_driver virtio_net_driver = {
4071	.feature_table = features,
4072	.feature_table_size = ARRAY_SIZE(features),
4073	.feature_table_legacy = features_legacy,
4074	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
4075	.driver.name =	KBUILD_MODNAME,
4076	.driver.owner =	THIS_MODULE,
4077	.id_table =	id_table,
4078	.validate =	virtnet_validate,
4079	.probe =	virtnet_probe,
4080	.remove =	virtnet_remove,
4081	.config_changed = virtnet_config_changed,
4082#ifdef CONFIG_PM_SLEEP
4083	.freeze =	virtnet_freeze,
4084	.restore =	virtnet_restore,
4085#endif
4086};
4087
4088static __init int virtio_net_driver_init(void)
4089{
4090	int ret;
4091
4092	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
4093				      virtnet_cpu_online,
4094				      virtnet_cpu_down_prep);
4095	if (ret < 0)
4096		goto out;
4097	virtionet_online = ret;
4098	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
4099				      NULL, virtnet_cpu_dead);
4100	if (ret)
4101		goto err_dead;
4102	ret = register_virtio_driver(&virtio_net_driver);
 
4103	if (ret)
4104		goto err_virtio;
4105	return 0;
4106err_virtio:
4107	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4108err_dead:
4109	cpuhp_remove_multi_state(virtionet_online);
4110out:
4111	return ret;
4112}
4113module_init(virtio_net_driver_init);
4114
4115static __exit void virtio_net_driver_exit(void)
4116{
4117	unregister_virtio_driver(&virtio_net_driver);
4118	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4119	cpuhp_remove_multi_state(virtionet_online);
4120}
4121module_exit(virtio_net_driver_exit);
4122
4123MODULE_DEVICE_TABLE(virtio, id_table);
4124MODULE_DESCRIPTION("Virtio network driver");
4125MODULE_LICENSE("GPL");