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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Virtio SCSI HBA driver
4 *
5 * Copyright IBM Corp. 2010
6 * Copyright Red Hat, Inc. 2011
7 *
8 * Authors:
9 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
10 * Paolo Bonzini <pbonzini@redhat.com>
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/mempool.h>
18#include <linux/interrupt.h>
19#include <linux/virtio.h>
20#include <linux/virtio_ids.h>
21#include <linux/virtio_config.h>
22#include <linux/virtio_scsi.h>
23#include <linux/cpu.h>
24#include <linux/blkdev.h>
25#include <linux/blk-integrity.h>
26#include <scsi/scsi_host.h>
27#include <scsi/scsi_device.h>
28#include <scsi/scsi_cmnd.h>
29#include <scsi/scsi_tcq.h>
30#include <scsi/scsi_devinfo.h>
31#include <linux/seqlock.h>
32#include <linux/blk-mq-virtio.h>
33
34#include "sd.h"
35
36#define VIRTIO_SCSI_MEMPOOL_SZ 64
37#define VIRTIO_SCSI_EVENT_LEN 8
38#define VIRTIO_SCSI_VQ_BASE 2
39
40static unsigned int virtscsi_poll_queues;
41module_param(virtscsi_poll_queues, uint, 0644);
42MODULE_PARM_DESC(virtscsi_poll_queues,
43 "The number of dedicated virtqueues for polling I/O");
44
45/* Command queue element */
46struct virtio_scsi_cmd {
47 struct scsi_cmnd *sc;
48 struct completion *comp;
49 union {
50 struct virtio_scsi_cmd_req cmd;
51 struct virtio_scsi_cmd_req_pi cmd_pi;
52 struct virtio_scsi_ctrl_tmf_req tmf;
53 struct virtio_scsi_ctrl_an_req an;
54 } req;
55 union {
56 struct virtio_scsi_cmd_resp cmd;
57 struct virtio_scsi_ctrl_tmf_resp tmf;
58 struct virtio_scsi_ctrl_an_resp an;
59 struct virtio_scsi_event evt;
60 } resp;
61} ____cacheline_aligned_in_smp;
62
63struct virtio_scsi_event_node {
64 struct virtio_scsi *vscsi;
65 struct virtio_scsi_event event;
66 struct work_struct work;
67};
68
69struct virtio_scsi_vq {
70 /* Protects vq */
71 spinlock_t vq_lock;
72
73 struct virtqueue *vq;
74};
75
76/* Driver instance state */
77struct virtio_scsi {
78 struct virtio_device *vdev;
79
80 /* Get some buffers ready for event vq */
81 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
82
83 u32 num_queues;
84 int io_queues[HCTX_MAX_TYPES];
85
86 struct hlist_node node;
87
88 /* Protected by event_vq lock */
89 bool stop_events;
90
91 struct virtio_scsi_vq ctrl_vq;
92 struct virtio_scsi_vq event_vq;
93 struct virtio_scsi_vq req_vqs[];
94};
95
96static struct kmem_cache *virtscsi_cmd_cache;
97static mempool_t *virtscsi_cmd_pool;
98
99static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
100{
101 return vdev->priv;
102}
103
104static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
105{
106 if (resid)
107 scsi_set_resid(sc, min(resid, scsi_bufflen(sc)));
108}
109
110/*
111 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
112 *
113 * Called with vq_lock held.
114 */
115static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
116{
117 struct virtio_scsi_cmd *cmd = buf;
118 struct scsi_cmnd *sc = cmd->sc;
119 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
120
121 dev_dbg(&sc->device->sdev_gendev,
122 "cmd %p response %u status %#02x sense_len %u\n",
123 sc, resp->response, resp->status, resp->sense_len);
124
125 sc->result = resp->status;
126 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid));
127 switch (resp->response) {
128 case VIRTIO_SCSI_S_OK:
129 set_host_byte(sc, DID_OK);
130 break;
131 case VIRTIO_SCSI_S_OVERRUN:
132 set_host_byte(sc, DID_ERROR);
133 break;
134 case VIRTIO_SCSI_S_ABORTED:
135 set_host_byte(sc, DID_ABORT);
136 break;
137 case VIRTIO_SCSI_S_BAD_TARGET:
138 set_host_byte(sc, DID_BAD_TARGET);
139 break;
140 case VIRTIO_SCSI_S_RESET:
141 set_host_byte(sc, DID_RESET);
142 break;
143 case VIRTIO_SCSI_S_BUSY:
144 set_host_byte(sc, DID_BUS_BUSY);
145 break;
146 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
147 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
148 break;
149 case VIRTIO_SCSI_S_TARGET_FAILURE:
150 set_host_byte(sc, DID_BAD_TARGET);
151 break;
152 case VIRTIO_SCSI_S_NEXUS_FAILURE:
153 set_status_byte(sc, SAM_STAT_RESERVATION_CONFLICT);
154 break;
155 default:
156 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
157 resp->response);
158 fallthrough;
159 case VIRTIO_SCSI_S_FAILURE:
160 set_host_byte(sc, DID_ERROR);
161 break;
162 }
163
164 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) >
165 VIRTIO_SCSI_SENSE_SIZE);
166 if (resp->sense_len) {
167 memcpy(sc->sense_buffer, resp->sense,
168 min_t(u32,
169 virtio32_to_cpu(vscsi->vdev, resp->sense_len),
170 VIRTIO_SCSI_SENSE_SIZE));
171 }
172
173 scsi_done(sc);
174}
175
176static void virtscsi_vq_done(struct virtio_scsi *vscsi,
177 struct virtio_scsi_vq *virtscsi_vq,
178 void (*fn)(struct virtio_scsi *vscsi, void *buf))
179{
180 void *buf;
181 unsigned int len;
182 unsigned long flags;
183 struct virtqueue *vq = virtscsi_vq->vq;
184
185 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
186 do {
187 virtqueue_disable_cb(vq);
188 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
189 fn(vscsi, buf);
190
191 } while (!virtqueue_enable_cb(vq));
192 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
193}
194
195static void virtscsi_req_done(struct virtqueue *vq)
196{
197 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
198 struct virtio_scsi *vscsi = shost_priv(sh);
199 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
200 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
201
202 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
203};
204
205static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
206{
207 int i, num_vqs;
208
209 num_vqs = vscsi->num_queues;
210 for (i = 0; i < num_vqs; i++)
211 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
212 virtscsi_complete_cmd);
213}
214
215static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
216{
217 struct virtio_scsi_cmd *cmd = buf;
218
219 if (cmd->comp)
220 complete(cmd->comp);
221}
222
223static void virtscsi_ctrl_done(struct virtqueue *vq)
224{
225 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
226 struct virtio_scsi *vscsi = shost_priv(sh);
227
228 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
229};
230
231static void virtscsi_handle_event(struct work_struct *work);
232
233static int virtscsi_kick_event(struct virtio_scsi *vscsi,
234 struct virtio_scsi_event_node *event_node)
235{
236 int err;
237 struct scatterlist sg;
238 unsigned long flags;
239
240 INIT_WORK(&event_node->work, virtscsi_handle_event);
241 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
242
243 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
244
245 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
246 GFP_ATOMIC);
247 if (!err)
248 virtqueue_kick(vscsi->event_vq.vq);
249
250 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
251
252 return err;
253}
254
255static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
256{
257 int i;
258
259 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
260 vscsi->event_list[i].vscsi = vscsi;
261 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
262 }
263
264 return 0;
265}
266
267static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
268{
269 int i;
270
271 /* Stop scheduling work before calling cancel_work_sync. */
272 spin_lock_irq(&vscsi->event_vq.vq_lock);
273 vscsi->stop_events = true;
274 spin_unlock_irq(&vscsi->event_vq.vq_lock);
275
276 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
277 cancel_work_sync(&vscsi->event_list[i].work);
278}
279
280static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
281 struct virtio_scsi_event *event)
282{
283 struct scsi_device *sdev;
284 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
285 unsigned int target = event->lun[1];
286 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
287
288 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) {
289 case VIRTIO_SCSI_EVT_RESET_RESCAN:
290 if (lun == 0) {
291 scsi_scan_target(&shost->shost_gendev, 0, target,
292 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);
293 } else {
294 scsi_add_device(shost, 0, target, lun);
295 }
296 break;
297 case VIRTIO_SCSI_EVT_RESET_REMOVED:
298 sdev = scsi_device_lookup(shost, 0, target, lun);
299 if (sdev) {
300 scsi_remove_device(sdev);
301 scsi_device_put(sdev);
302 } else {
303 pr_err("SCSI device %d 0 %d %d not found\n",
304 shost->host_no, target, lun);
305 }
306 break;
307 default:
308 pr_info("Unsupported virtio scsi event reason %x\n", event->reason);
309 }
310}
311
312static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
313 struct virtio_scsi_event *event)
314{
315 struct scsi_device *sdev;
316 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
317 unsigned int target = event->lun[1];
318 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
319 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255;
320 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8;
321
322 sdev = scsi_device_lookup(shost, 0, target, lun);
323 if (!sdev) {
324 pr_err("SCSI device %d 0 %d %d not found\n",
325 shost->host_no, target, lun);
326 return;
327 }
328
329 /* Handle "Parameters changed", "Mode parameters changed", and
330 "Capacity data has changed". */
331 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
332 scsi_rescan_device(sdev);
333
334 scsi_device_put(sdev);
335}
336
337static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi)
338{
339 struct scsi_device *sdev;
340 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
341 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
342 int result, inquiry_len, inq_result_len = 256;
343 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL);
344
345 if (!inq_result)
346 return -ENOMEM;
347
348 shost_for_each_device(sdev, shost) {
349 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
350
351 memset(scsi_cmd, 0, sizeof(scsi_cmd));
352 scsi_cmd[0] = INQUIRY;
353 scsi_cmd[4] = (unsigned char) inquiry_len;
354
355 memset(inq_result, 0, inq_result_len);
356
357 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,
358 inq_result, inquiry_len,
359 SD_TIMEOUT, SD_MAX_RETRIES, NULL);
360
361 if (result == 0 && inq_result[0] >> 5) {
362 /* PQ indicates the LUN is not attached */
363 scsi_remove_device(sdev);
364 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) {
365 /*
366 * If all LUNs of a virtio-scsi device are unplugged
367 * it will respond with BAD TARGET on any INQUIRY
368 * command.
369 * Remove the device in this case as well.
370 */
371 scsi_remove_device(sdev);
372 }
373 }
374
375 kfree(inq_result);
376 return 0;
377}
378
379static void virtscsi_handle_event(struct work_struct *work)
380{
381 struct virtio_scsi_event_node *event_node =
382 container_of(work, struct virtio_scsi_event_node, work);
383 struct virtio_scsi *vscsi = event_node->vscsi;
384 struct virtio_scsi_event *event = &event_node->event;
385
386 if (event->event &
387 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) {
388 int ret;
389
390 event->event &= ~cpu_to_virtio32(vscsi->vdev,
391 VIRTIO_SCSI_T_EVENTS_MISSED);
392 ret = virtscsi_rescan_hotunplug(vscsi);
393 if (ret)
394 return;
395 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
396 }
397
398 switch (virtio32_to_cpu(vscsi->vdev, event->event)) {
399 case VIRTIO_SCSI_T_NO_EVENT:
400 break;
401 case VIRTIO_SCSI_T_TRANSPORT_RESET:
402 virtscsi_handle_transport_reset(vscsi, event);
403 break;
404 case VIRTIO_SCSI_T_PARAM_CHANGE:
405 virtscsi_handle_param_change(vscsi, event);
406 break;
407 default:
408 pr_err("Unsupported virtio scsi event %x\n", event->event);
409 }
410 virtscsi_kick_event(vscsi, event_node);
411}
412
413static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
414{
415 struct virtio_scsi_event_node *event_node = buf;
416
417 if (!vscsi->stop_events)
418 queue_work(system_freezable_wq, &event_node->work);
419}
420
421static void virtscsi_event_done(struct virtqueue *vq)
422{
423 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
424 struct virtio_scsi *vscsi = shost_priv(sh);
425
426 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
427};
428
429static int __virtscsi_add_cmd(struct virtqueue *vq,
430 struct virtio_scsi_cmd *cmd,
431 size_t req_size, size_t resp_size)
432{
433 struct scsi_cmnd *sc = cmd->sc;
434 struct scatterlist *sgs[6], req, resp;
435 struct sg_table *out, *in;
436 unsigned out_num = 0, in_num = 0;
437
438 out = in = NULL;
439
440 if (sc && sc->sc_data_direction != DMA_NONE) {
441 if (sc->sc_data_direction != DMA_FROM_DEVICE)
442 out = &sc->sdb.table;
443 if (sc->sc_data_direction != DMA_TO_DEVICE)
444 in = &sc->sdb.table;
445 }
446
447 /* Request header. */
448 sg_init_one(&req, &cmd->req, req_size);
449 sgs[out_num++] = &req;
450
451 /* Data-out buffer. */
452 if (out) {
453 /* Place WRITE protection SGLs before Data OUT payload */
454 if (scsi_prot_sg_count(sc))
455 sgs[out_num++] = scsi_prot_sglist(sc);
456 sgs[out_num++] = out->sgl;
457 }
458
459 /* Response header. */
460 sg_init_one(&resp, &cmd->resp, resp_size);
461 sgs[out_num + in_num++] = &resp;
462
463 /* Data-in buffer */
464 if (in) {
465 /* Place READ protection SGLs before Data IN payload */
466 if (scsi_prot_sg_count(sc))
467 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
468 sgs[out_num + in_num++] = in->sgl;
469 }
470
471 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
472}
473
474static void virtscsi_kick_vq(struct virtio_scsi_vq *vq)
475{
476 bool needs_kick;
477 unsigned long flags;
478
479 spin_lock_irqsave(&vq->vq_lock, flags);
480 needs_kick = virtqueue_kick_prepare(vq->vq);
481 spin_unlock_irqrestore(&vq->vq_lock, flags);
482
483 if (needs_kick)
484 virtqueue_notify(vq->vq);
485}
486
487/**
488 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it
489 * @vq : the struct virtqueue we're talking about
490 * @cmd : command structure
491 * @req_size : size of the request buffer
492 * @resp_size : size of the response buffer
493 * @kick : whether to kick the virtqueue immediately
494 */
495static int virtscsi_add_cmd(struct virtio_scsi_vq *vq,
496 struct virtio_scsi_cmd *cmd,
497 size_t req_size, size_t resp_size,
498 bool kick)
499{
500 unsigned long flags;
501 int err;
502 bool needs_kick = false;
503
504 spin_lock_irqsave(&vq->vq_lock, flags);
505 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
506 if (!err && kick)
507 needs_kick = virtqueue_kick_prepare(vq->vq);
508
509 spin_unlock_irqrestore(&vq->vq_lock, flags);
510
511 if (needs_kick)
512 virtqueue_notify(vq->vq);
513 return err;
514}
515
516static void virtio_scsi_init_hdr(struct virtio_device *vdev,
517 struct virtio_scsi_cmd_req *cmd,
518 struct scsi_cmnd *sc)
519{
520 cmd->lun[0] = 1;
521 cmd->lun[1] = sc->device->id;
522 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
523 cmd->lun[3] = sc->device->lun & 0xff;
524 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc);
525 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
526 cmd->prio = 0;
527 cmd->crn = 0;
528}
529
530#ifdef CONFIG_BLK_DEV_INTEGRITY
531static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
532 struct virtio_scsi_cmd_req_pi *cmd_pi,
533 struct scsi_cmnd *sc)
534{
535 struct request *rq = scsi_cmd_to_rq(sc);
536 struct blk_integrity *bi;
537
538 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc);
539
540 if (!rq || !scsi_prot_sg_count(sc))
541 return;
542
543 bi = blk_get_integrity(rq->q->disk);
544
545 if (sc->sc_data_direction == DMA_TO_DEVICE)
546 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev,
547 bio_integrity_bytes(bi,
548 blk_rq_sectors(rq)));
549 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
550 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev,
551 bio_integrity_bytes(bi,
552 blk_rq_sectors(rq)));
553}
554#endif
555
556static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
557 struct scsi_cmnd *sc)
558{
559 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc));
560 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
561
562 return &vscsi->req_vqs[hwq];
563}
564
565static int virtscsi_queuecommand(struct Scsi_Host *shost,
566 struct scsi_cmnd *sc)
567{
568 struct virtio_scsi *vscsi = shost_priv(shost);
569 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
570 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
571 bool kick;
572 unsigned long flags;
573 int req_size;
574 int ret;
575
576 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
577
578 /* TODO: check feature bit and fail if unsupported? */
579 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
580
581 dev_dbg(&sc->device->sdev_gendev,
582 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
583
584 cmd->sc = sc;
585
586 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
587
588#ifdef CONFIG_BLK_DEV_INTEGRITY
589 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
590 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
591 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
592 req_size = sizeof(cmd->req.cmd_pi);
593 } else
594#endif
595 {
596 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
597 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
598 req_size = sizeof(cmd->req.cmd);
599 }
600
601 kick = (sc->flags & SCMD_LAST) != 0;
602 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick);
603 if (ret == -EIO) {
604 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
605 spin_lock_irqsave(&req_vq->vq_lock, flags);
606 virtscsi_complete_cmd(vscsi, cmd);
607 spin_unlock_irqrestore(&req_vq->vq_lock, flags);
608 } else if (ret != 0) {
609 return SCSI_MLQUEUE_HOST_BUSY;
610 }
611 return 0;
612}
613
614static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
615{
616 DECLARE_COMPLETION_ONSTACK(comp);
617 int ret = FAILED;
618
619 cmd->comp = ∁
620 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd,
621 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0)
622 goto out;
623
624 wait_for_completion(&comp);
625 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
626 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
627 ret = SUCCESS;
628
629 /*
630 * The spec guarantees that all requests related to the TMF have
631 * been completed, but the callback might not have run yet if
632 * we're using independent interrupts (e.g. MSI). Poll the
633 * virtqueues once.
634 *
635 * In the abort case, scsi_done() will do nothing, because the
636 * command timed out and hence SCMD_STATE_COMPLETE has been set.
637 */
638 virtscsi_poll_requests(vscsi);
639
640out:
641 mempool_free(cmd, virtscsi_cmd_pool);
642 return ret;
643}
644
645static int virtscsi_device_reset(struct scsi_cmnd *sc)
646{
647 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
648 struct virtio_scsi_cmd *cmd;
649
650 sdev_printk(KERN_INFO, sc->device, "device reset\n");
651 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
652 if (!cmd)
653 return FAILED;
654
655 memset(cmd, 0, sizeof(*cmd));
656 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
657 .type = VIRTIO_SCSI_T_TMF,
658 .subtype = cpu_to_virtio32(vscsi->vdev,
659 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET),
660 .lun[0] = 1,
661 .lun[1] = sc->device->id,
662 .lun[2] = (sc->device->lun >> 8) | 0x40,
663 .lun[3] = sc->device->lun & 0xff,
664 };
665 return virtscsi_tmf(vscsi, cmd);
666}
667
668static int virtscsi_device_alloc(struct scsi_device *sdevice)
669{
670 /*
671 * Passed through SCSI targets (e.g. with qemu's 'scsi-block')
672 * may have transfer limits which come from the host SCSI
673 * controller or something on the host side other than the
674 * target itself.
675 *
676 * To make this work properly, the hypervisor can adjust the
677 * target's VPD information to advertise these limits. But
678 * for that to work, the guest has to look at the VPD pages,
679 * which we won't do by default if it is an SPC-2 device, even
680 * if it does actually support it.
681 *
682 * So, set the blist to always try to read the VPD pages.
683 */
684 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES;
685
686 return 0;
687}
688
689
690/**
691 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
692 * @sdev: Virtscsi target whose queue depth to change
693 * @qdepth: New queue depth
694 */
695static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
696{
697 struct Scsi_Host *shost = sdev->host;
698 int max_depth = shost->cmd_per_lun;
699
700 return scsi_change_queue_depth(sdev, min(max_depth, qdepth));
701}
702
703static int virtscsi_abort(struct scsi_cmnd *sc)
704{
705 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
706 struct virtio_scsi_cmd *cmd;
707
708 scmd_printk(KERN_INFO, sc, "abort\n");
709 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
710 if (!cmd)
711 return FAILED;
712
713 memset(cmd, 0, sizeof(*cmd));
714 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
715 .type = VIRTIO_SCSI_T_TMF,
716 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
717 .lun[0] = 1,
718 .lun[1] = sc->device->id,
719 .lun[2] = (sc->device->lun >> 8) | 0x40,
720 .lun[3] = sc->device->lun & 0xff,
721 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc),
722 };
723 return virtscsi_tmf(vscsi, cmd);
724}
725
726static void virtscsi_map_queues(struct Scsi_Host *shost)
727{
728 struct virtio_scsi *vscsi = shost_priv(shost);
729 int i, qoff;
730
731 for (i = 0, qoff = 0; i < shost->nr_maps; i++) {
732 struct blk_mq_queue_map *map = &shost->tag_set.map[i];
733
734 map->nr_queues = vscsi->io_queues[i];
735 map->queue_offset = qoff;
736 qoff += map->nr_queues;
737
738 if (map->nr_queues == 0)
739 continue;
740
741 /*
742 * Regular queues have interrupts and hence CPU affinity is
743 * defined by the core virtio code, but polling queues have
744 * no interrupts so we let the block layer assign CPU affinity.
745 */
746 if (i == HCTX_TYPE_POLL)
747 blk_mq_map_queues(map);
748 else
749 blk_mq_virtio_map_queues(map, vscsi->vdev, 2);
750 }
751}
752
753static int virtscsi_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
754{
755 struct virtio_scsi *vscsi = shost_priv(shost);
756 struct virtio_scsi_vq *virtscsi_vq = &vscsi->req_vqs[queue_num];
757 unsigned long flags;
758 unsigned int len;
759 int found = 0;
760 void *buf;
761
762 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
763
764 while ((buf = virtqueue_get_buf(virtscsi_vq->vq, &len)) != NULL) {
765 virtscsi_complete_cmd(vscsi, buf);
766 found++;
767 }
768
769 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
770
771 return found;
772}
773
774static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq)
775{
776 struct virtio_scsi *vscsi = shost_priv(shost);
777
778 virtscsi_kick_vq(&vscsi->req_vqs[hwq]);
779}
780
781/*
782 * The host guarantees to respond to each command, although I/O
783 * latencies might be higher than on bare metal. Reset the timer
784 * unconditionally to give the host a chance to perform EH.
785 */
786static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
787{
788 return SCSI_EH_RESET_TIMER;
789}
790
791static const struct scsi_host_template virtscsi_host_template = {
792 .module = THIS_MODULE,
793 .name = "Virtio SCSI HBA",
794 .proc_name = "virtio_scsi",
795 .this_id = -1,
796 .cmd_size = sizeof(struct virtio_scsi_cmd),
797 .queuecommand = virtscsi_queuecommand,
798 .mq_poll = virtscsi_mq_poll,
799 .commit_rqs = virtscsi_commit_rqs,
800 .change_queue_depth = virtscsi_change_queue_depth,
801 .eh_abort_handler = virtscsi_abort,
802 .eh_device_reset_handler = virtscsi_device_reset,
803 .eh_timed_out = virtscsi_eh_timed_out,
804 .slave_alloc = virtscsi_device_alloc,
805
806 .dma_boundary = UINT_MAX,
807 .map_queues = virtscsi_map_queues,
808 .track_queue_depth = 1,
809};
810
811#define virtscsi_config_get(vdev, fld) \
812 ({ \
813 __virtio_native_type(struct virtio_scsi_config, fld) __val; \
814 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
815 __val; \
816 })
817
818#define virtscsi_config_set(vdev, fld, val) \
819 do { \
820 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \
821 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
822 } while(0)
823
824static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
825 struct virtqueue *vq)
826{
827 spin_lock_init(&virtscsi_vq->vq_lock);
828 virtscsi_vq->vq = vq;
829}
830
831static void virtscsi_remove_vqs(struct virtio_device *vdev)
832{
833 /* Stop all the virtqueues. */
834 virtio_reset_device(vdev);
835 vdev->config->del_vqs(vdev);
836}
837
838static int virtscsi_init(struct virtio_device *vdev,
839 struct virtio_scsi *vscsi)
840{
841 int err;
842 u32 i;
843 u32 num_vqs, num_poll_vqs, num_req_vqs;
844 vq_callback_t **callbacks;
845 const char **names;
846 struct virtqueue **vqs;
847 struct irq_affinity desc = { .pre_vectors = 2 };
848
849 num_req_vqs = vscsi->num_queues;
850 num_vqs = num_req_vqs + VIRTIO_SCSI_VQ_BASE;
851 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL);
852 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *),
853 GFP_KERNEL);
854 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL);
855
856 if (!callbacks || !vqs || !names) {
857 err = -ENOMEM;
858 goto out;
859 }
860
861 num_poll_vqs = min_t(unsigned int, virtscsi_poll_queues,
862 num_req_vqs - 1);
863 vscsi->io_queues[HCTX_TYPE_DEFAULT] = num_req_vqs - num_poll_vqs;
864 vscsi->io_queues[HCTX_TYPE_READ] = 0;
865 vscsi->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
866
867 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
868 vscsi->io_queues[HCTX_TYPE_DEFAULT],
869 vscsi->io_queues[HCTX_TYPE_READ],
870 vscsi->io_queues[HCTX_TYPE_POLL]);
871
872 callbacks[0] = virtscsi_ctrl_done;
873 callbacks[1] = virtscsi_event_done;
874 names[0] = "control";
875 names[1] = "event";
876 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs - num_poll_vqs; i++) {
877 callbacks[i] = virtscsi_req_done;
878 names[i] = "request";
879 }
880
881 for (; i < num_vqs; i++) {
882 callbacks[i] = NULL;
883 names[i] = "request_poll";
884 }
885
886 /* Discover virtqueues and write information to configuration. */
887 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
888 if (err)
889 goto out;
890
891 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
892 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
893 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
894 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
895 vqs[i]);
896
897 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
898 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
899
900 err = 0;
901
902out:
903 kfree(names);
904 kfree(callbacks);
905 kfree(vqs);
906 if (err)
907 virtscsi_remove_vqs(vdev);
908 return err;
909}
910
911static int virtscsi_probe(struct virtio_device *vdev)
912{
913 struct Scsi_Host *shost;
914 struct virtio_scsi *vscsi;
915 int err;
916 u32 sg_elems, num_targets;
917 u32 cmd_per_lun;
918 u32 num_queues;
919
920 if (!vdev->config->get) {
921 dev_err(&vdev->dev, "%s failure: config access disabled\n",
922 __func__);
923 return -EINVAL;
924 }
925
926 /* We need to know how many queues before we allocate. */
927 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
928 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
929
930 num_targets = virtscsi_config_get(vdev, max_target) + 1;
931
932 shost = scsi_host_alloc(&virtscsi_host_template,
933 struct_size(vscsi, req_vqs, num_queues));
934 if (!shost)
935 return -ENOMEM;
936
937 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
938 shost->sg_tablesize = sg_elems;
939 shost->nr_maps = 1;
940 vscsi = shost_priv(shost);
941 vscsi->vdev = vdev;
942 vscsi->num_queues = num_queues;
943 vdev->priv = shost;
944
945 err = virtscsi_init(vdev, vscsi);
946 if (err)
947 goto virtscsi_init_failed;
948
949 if (vscsi->io_queues[HCTX_TYPE_POLL])
950 shost->nr_maps = HCTX_TYPE_POLL + 1;
951
952 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq);
953
954 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
955 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
956 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
957
958 /* LUNs > 256 are reported with format 1, so they go in the range
959 * 16640-32767.
960 */
961 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
962 shost->max_id = num_targets;
963 shost->max_channel = 0;
964 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
965 shost->nr_hw_queues = num_queues;
966
967#ifdef CONFIG_BLK_DEV_INTEGRITY
968 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
969 int host_prot;
970
971 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
972 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
973 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
974
975 scsi_host_set_prot(shost, host_prot);
976 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
977 }
978#endif
979
980 err = scsi_add_host(shost, &vdev->dev);
981 if (err)
982 goto scsi_add_host_failed;
983
984 virtio_device_ready(vdev);
985
986 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
987 virtscsi_kick_event_all(vscsi);
988
989 scsi_scan_host(shost);
990 return 0;
991
992scsi_add_host_failed:
993 vdev->config->del_vqs(vdev);
994virtscsi_init_failed:
995 scsi_host_put(shost);
996 return err;
997}
998
999static void virtscsi_remove(struct virtio_device *vdev)
1000{
1001 struct Scsi_Host *shost = virtio_scsi_host(vdev);
1002 struct virtio_scsi *vscsi = shost_priv(shost);
1003
1004 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
1005 virtscsi_cancel_event_work(vscsi);
1006
1007 scsi_remove_host(shost);
1008 virtscsi_remove_vqs(vdev);
1009 scsi_host_put(shost);
1010}
1011
1012#ifdef CONFIG_PM_SLEEP
1013static int virtscsi_freeze(struct virtio_device *vdev)
1014{
1015 virtscsi_remove_vqs(vdev);
1016 return 0;
1017}
1018
1019static int virtscsi_restore(struct virtio_device *vdev)
1020{
1021 struct Scsi_Host *sh = virtio_scsi_host(vdev);
1022 struct virtio_scsi *vscsi = shost_priv(sh);
1023 int err;
1024
1025 err = virtscsi_init(vdev, vscsi);
1026 if (err)
1027 return err;
1028
1029 virtio_device_ready(vdev);
1030
1031 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
1032 virtscsi_kick_event_all(vscsi);
1033
1034 return err;
1035}
1036#endif
1037
1038static struct virtio_device_id id_table[] = {
1039 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
1040 { 0 },
1041};
1042
1043static unsigned int features[] = {
1044 VIRTIO_SCSI_F_HOTPLUG,
1045 VIRTIO_SCSI_F_CHANGE,
1046#ifdef CONFIG_BLK_DEV_INTEGRITY
1047 VIRTIO_SCSI_F_T10_PI,
1048#endif
1049};
1050
1051static struct virtio_driver virtio_scsi_driver = {
1052 .feature_table = features,
1053 .feature_table_size = ARRAY_SIZE(features),
1054 .driver.name = KBUILD_MODNAME,
1055 .driver.owner = THIS_MODULE,
1056 .id_table = id_table,
1057 .probe = virtscsi_probe,
1058#ifdef CONFIG_PM_SLEEP
1059 .freeze = virtscsi_freeze,
1060 .restore = virtscsi_restore,
1061#endif
1062 .remove = virtscsi_remove,
1063};
1064
1065static int __init virtio_scsi_init(void)
1066{
1067 int ret = -ENOMEM;
1068
1069 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1070 if (!virtscsi_cmd_cache) {
1071 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1072 goto error;
1073 }
1074
1075
1076 virtscsi_cmd_pool =
1077 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1078 virtscsi_cmd_cache);
1079 if (!virtscsi_cmd_pool) {
1080 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1081 goto error;
1082 }
1083 ret = register_virtio_driver(&virtio_scsi_driver);
1084 if (ret < 0)
1085 goto error;
1086
1087 return 0;
1088
1089error:
1090 mempool_destroy(virtscsi_cmd_pool);
1091 virtscsi_cmd_pool = NULL;
1092 kmem_cache_destroy(virtscsi_cmd_cache);
1093 virtscsi_cmd_cache = NULL;
1094 return ret;
1095}
1096
1097static void __exit virtio_scsi_fini(void)
1098{
1099 unregister_virtio_driver(&virtio_scsi_driver);
1100 mempool_destroy(virtscsi_cmd_pool);
1101 kmem_cache_destroy(virtscsi_cmd_cache);
1102}
1103module_init(virtio_scsi_init);
1104module_exit(virtio_scsi_fini);
1105
1106MODULE_DEVICE_TABLE(virtio, id_table);
1107MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1108MODULE_LICENSE("GPL");