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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 */
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/wait.h>
14#include <linux/mm.h>
15#include <linux/slab.h>
16#include <linux/module.h>
17#include <linux/hyperv.h>
18#include <linux/uio.h>
19#include <linux/interrupt.h>
20#include <asm/page.h>
21#include <asm/mshyperv.h>
22
23#include "hyperv_vmbus.h"
24
25#define NUM_PAGES_SPANNED(addr, len) \
26((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
27
28static unsigned long virt_to_hvpfn(void *addr)
29{
30 phys_addr_t paddr;
31
32 if (is_vmalloc_addr(addr))
33 paddr = page_to_phys(vmalloc_to_page(addr)) +
34 offset_in_page(addr);
35 else
36 paddr = __pa(addr);
37
38 return paddr >> PAGE_SHIFT;
39}
40
41/*
42 * vmbus_setevent- Trigger an event notification on the specified
43 * channel.
44 */
45void vmbus_setevent(struct vmbus_channel *channel)
46{
47 struct hv_monitor_page *monitorpage;
48
49 trace_vmbus_setevent(channel);
50
51 /*
52 * For channels marked as in "low latency" mode
53 * bypass the monitor page mechanism.
54 */
55 if (channel->offermsg.monitor_allocated && !channel->low_latency) {
56 vmbus_send_interrupt(channel->offermsg.child_relid);
57
58 /* Get the child to parent monitor page */
59 monitorpage = vmbus_connection.monitor_pages[1];
60
61 sync_set_bit(channel->monitor_bit,
62 (unsigned long *)&monitorpage->trigger_group
63 [channel->monitor_grp].pending);
64
65 } else {
66 vmbus_set_event(channel);
67 }
68}
69EXPORT_SYMBOL_GPL(vmbus_setevent);
70
71/* vmbus_free_ring - drop mapping of ring buffer */
72void vmbus_free_ring(struct vmbus_channel *channel)
73{
74 hv_ringbuffer_cleanup(&channel->outbound);
75 hv_ringbuffer_cleanup(&channel->inbound);
76
77 if (channel->ringbuffer_page) {
78 __free_pages(channel->ringbuffer_page,
79 get_order(channel->ringbuffer_pagecount
80 << PAGE_SHIFT));
81 channel->ringbuffer_page = NULL;
82 }
83}
84EXPORT_SYMBOL_GPL(vmbus_free_ring);
85
86/* vmbus_alloc_ring - allocate and map pages for ring buffer */
87int vmbus_alloc_ring(struct vmbus_channel *newchannel,
88 u32 send_size, u32 recv_size)
89{
90 struct page *page;
91 int order;
92
93 if (send_size % PAGE_SIZE || recv_size % PAGE_SIZE)
94 return -EINVAL;
95
96 /* Allocate the ring buffer */
97 order = get_order(send_size + recv_size);
98 page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
99 GFP_KERNEL|__GFP_ZERO, order);
100
101 if (!page)
102 page = alloc_pages(GFP_KERNEL|__GFP_ZERO, order);
103
104 if (!page)
105 return -ENOMEM;
106
107 newchannel->ringbuffer_page = page;
108 newchannel->ringbuffer_pagecount = (send_size + recv_size) >> PAGE_SHIFT;
109 newchannel->ringbuffer_send_offset = send_size >> PAGE_SHIFT;
110
111 return 0;
112}
113EXPORT_SYMBOL_GPL(vmbus_alloc_ring);
114
115static int __vmbus_open(struct vmbus_channel *newchannel,
116 void *userdata, u32 userdatalen,
117 void (*onchannelcallback)(void *context), void *context)
118{
119 struct vmbus_channel_open_channel *open_msg;
120 struct vmbus_channel_msginfo *open_info = NULL;
121 struct page *page = newchannel->ringbuffer_page;
122 u32 send_pages, recv_pages;
123 unsigned long flags;
124 int err;
125
126 if (userdatalen > MAX_USER_DEFINED_BYTES)
127 return -EINVAL;
128
129 send_pages = newchannel->ringbuffer_send_offset;
130 recv_pages = newchannel->ringbuffer_pagecount - send_pages;
131
132 if (newchannel->state != CHANNEL_OPEN_STATE)
133 return -EINVAL;
134
135 newchannel->state = CHANNEL_OPENING_STATE;
136 newchannel->onchannel_callback = onchannelcallback;
137 newchannel->channel_callback_context = context;
138
139 err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages);
140 if (err)
141 goto error_clean_ring;
142
143 err = hv_ringbuffer_init(&newchannel->inbound,
144 &page[send_pages], recv_pages);
145 if (err)
146 goto error_clean_ring;
147
148 /* Establish the gpadl for the ring buffer */
149 newchannel->ringbuffer_gpadlhandle = 0;
150
151 err = vmbus_establish_gpadl(newchannel,
152 page_address(newchannel->ringbuffer_page),
153 (send_pages + recv_pages) << PAGE_SHIFT,
154 &newchannel->ringbuffer_gpadlhandle);
155 if (err)
156 goto error_clean_ring;
157
158 /* Create and init the channel open message */
159 open_info = kmalloc(sizeof(*open_info) +
160 sizeof(struct vmbus_channel_open_channel),
161 GFP_KERNEL);
162 if (!open_info) {
163 err = -ENOMEM;
164 goto error_free_gpadl;
165 }
166
167 init_completion(&open_info->waitevent);
168 open_info->waiting_channel = newchannel;
169
170 open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
171 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
172 open_msg->openid = newchannel->offermsg.child_relid;
173 open_msg->child_relid = newchannel->offermsg.child_relid;
174 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
175 open_msg->downstream_ringbuffer_pageoffset = newchannel->ringbuffer_send_offset;
176 open_msg->target_vp = hv_cpu_number_to_vp_number(newchannel->target_cpu);
177
178 if (userdatalen)
179 memcpy(open_msg->userdata, userdata, userdatalen);
180
181 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
182 list_add_tail(&open_info->msglistentry,
183 &vmbus_connection.chn_msg_list);
184 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
185
186 if (newchannel->rescind) {
187 err = -ENODEV;
188 goto error_free_info;
189 }
190
191 err = vmbus_post_msg(open_msg,
192 sizeof(struct vmbus_channel_open_channel), true);
193
194 trace_vmbus_open(open_msg, err);
195
196 if (err != 0)
197 goto error_clean_msglist;
198
199 wait_for_completion(&open_info->waitevent);
200
201 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
202 list_del(&open_info->msglistentry);
203 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
204
205 if (newchannel->rescind) {
206 err = -ENODEV;
207 goto error_free_info;
208 }
209
210 if (open_info->response.open_result.status) {
211 err = -EAGAIN;
212 goto error_free_info;
213 }
214
215 newchannel->state = CHANNEL_OPENED_STATE;
216 kfree(open_info);
217 return 0;
218
219error_clean_msglist:
220 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
221 list_del(&open_info->msglistentry);
222 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
223error_free_info:
224 kfree(open_info);
225error_free_gpadl:
226 vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
227 newchannel->ringbuffer_gpadlhandle = 0;
228error_clean_ring:
229 hv_ringbuffer_cleanup(&newchannel->outbound);
230 hv_ringbuffer_cleanup(&newchannel->inbound);
231 newchannel->state = CHANNEL_OPEN_STATE;
232 return err;
233}
234
235/*
236 * vmbus_connect_ring - Open the channel but reuse ring buffer
237 */
238int vmbus_connect_ring(struct vmbus_channel *newchannel,
239 void (*onchannelcallback)(void *context), void *context)
240{
241 return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context);
242}
243EXPORT_SYMBOL_GPL(vmbus_connect_ring);
244
245/*
246 * vmbus_open - Open the specified channel.
247 */
248int vmbus_open(struct vmbus_channel *newchannel,
249 u32 send_ringbuffer_size, u32 recv_ringbuffer_size,
250 void *userdata, u32 userdatalen,
251 void (*onchannelcallback)(void *context), void *context)
252{
253 int err;
254
255 err = vmbus_alloc_ring(newchannel, send_ringbuffer_size,
256 recv_ringbuffer_size);
257 if (err)
258 return err;
259
260 err = __vmbus_open(newchannel, userdata, userdatalen,
261 onchannelcallback, context);
262 if (err)
263 vmbus_free_ring(newchannel);
264
265 return err;
266}
267EXPORT_SYMBOL_GPL(vmbus_open);
268
269/* Used for Hyper-V Socket: a guest client's connect() to the host */
270int vmbus_send_tl_connect_request(const guid_t *shv_guest_servie_id,
271 const guid_t *shv_host_servie_id)
272{
273 struct vmbus_channel_tl_connect_request conn_msg;
274 int ret;
275
276 memset(&conn_msg, 0, sizeof(conn_msg));
277 conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
278 conn_msg.guest_endpoint_id = *shv_guest_servie_id;
279 conn_msg.host_service_id = *shv_host_servie_id;
280
281 ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
282
283 trace_vmbus_send_tl_connect_request(&conn_msg, ret);
284
285 return ret;
286}
287EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
288
289/*
290 * Set/change the vCPU (@target_vp) the channel (@child_relid) will interrupt.
291 *
292 * CHANNELMSG_MODIFYCHANNEL messages are aynchronous. Also, Hyper-V does not
293 * ACK such messages. IOW we can't know when the host will stop interrupting
294 * the "old" vCPU and start interrupting the "new" vCPU for the given channel.
295 *
296 * The CHANNELMSG_MODIFYCHANNEL message type is supported since VMBus version
297 * VERSION_WIN10_V4_1.
298 */
299int vmbus_send_modifychannel(u32 child_relid, u32 target_vp)
300{
301 struct vmbus_channel_modifychannel conn_msg;
302 int ret;
303
304 memset(&conn_msg, 0, sizeof(conn_msg));
305 conn_msg.header.msgtype = CHANNELMSG_MODIFYCHANNEL;
306 conn_msg.child_relid = child_relid;
307 conn_msg.target_vp = target_vp;
308
309 ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
310
311 trace_vmbus_send_modifychannel(&conn_msg, ret);
312
313 return ret;
314}
315EXPORT_SYMBOL_GPL(vmbus_send_modifychannel);
316
317/*
318 * create_gpadl_header - Creates a gpadl for the specified buffer
319 */
320static int create_gpadl_header(void *kbuffer, u32 size,
321 struct vmbus_channel_msginfo **msginfo)
322{
323 int i;
324 int pagecount;
325 struct vmbus_channel_gpadl_header *gpadl_header;
326 struct vmbus_channel_gpadl_body *gpadl_body;
327 struct vmbus_channel_msginfo *msgheader;
328 struct vmbus_channel_msginfo *msgbody = NULL;
329 u32 msgsize;
330
331 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
332
333 pagecount = size >> PAGE_SHIFT;
334
335 /* do we need a gpadl body msg */
336 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
337 sizeof(struct vmbus_channel_gpadl_header) -
338 sizeof(struct gpa_range);
339 pfncount = pfnsize / sizeof(u64);
340
341 if (pagecount > pfncount) {
342 /* we need a gpadl body */
343 /* fill in the header */
344 msgsize = sizeof(struct vmbus_channel_msginfo) +
345 sizeof(struct vmbus_channel_gpadl_header) +
346 sizeof(struct gpa_range) + pfncount * sizeof(u64);
347 msgheader = kzalloc(msgsize, GFP_KERNEL);
348 if (!msgheader)
349 goto nomem;
350
351 INIT_LIST_HEAD(&msgheader->submsglist);
352 msgheader->msgsize = msgsize;
353
354 gpadl_header = (struct vmbus_channel_gpadl_header *)
355 msgheader->msg;
356 gpadl_header->rangecount = 1;
357 gpadl_header->range_buflen = sizeof(struct gpa_range) +
358 pagecount * sizeof(u64);
359 gpadl_header->range[0].byte_offset = 0;
360 gpadl_header->range[0].byte_count = size;
361 for (i = 0; i < pfncount; i++)
362 gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
363 kbuffer + PAGE_SIZE * i);
364 *msginfo = msgheader;
365
366 pfnsum = pfncount;
367 pfnleft = pagecount - pfncount;
368
369 /* how many pfns can we fit */
370 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
371 sizeof(struct vmbus_channel_gpadl_body);
372 pfncount = pfnsize / sizeof(u64);
373
374 /* fill in the body */
375 while (pfnleft) {
376 if (pfnleft > pfncount)
377 pfncurr = pfncount;
378 else
379 pfncurr = pfnleft;
380
381 msgsize = sizeof(struct vmbus_channel_msginfo) +
382 sizeof(struct vmbus_channel_gpadl_body) +
383 pfncurr * sizeof(u64);
384 msgbody = kzalloc(msgsize, GFP_KERNEL);
385
386 if (!msgbody) {
387 struct vmbus_channel_msginfo *pos = NULL;
388 struct vmbus_channel_msginfo *tmp = NULL;
389 /*
390 * Free up all the allocated messages.
391 */
392 list_for_each_entry_safe(pos, tmp,
393 &msgheader->submsglist,
394 msglistentry) {
395
396 list_del(&pos->msglistentry);
397 kfree(pos);
398 }
399
400 goto nomem;
401 }
402
403 msgbody->msgsize = msgsize;
404 gpadl_body =
405 (struct vmbus_channel_gpadl_body *)msgbody->msg;
406
407 /*
408 * Gpadl is u32 and we are using a pointer which could
409 * be 64-bit
410 * This is governed by the guest/host protocol and
411 * so the hypervisor guarantees that this is ok.
412 */
413 for (i = 0; i < pfncurr; i++)
414 gpadl_body->pfn[i] = virt_to_hvpfn(
415 kbuffer + PAGE_SIZE * (pfnsum + i));
416
417 /* add to msg header */
418 list_add_tail(&msgbody->msglistentry,
419 &msgheader->submsglist);
420 pfnsum += pfncurr;
421 pfnleft -= pfncurr;
422 }
423 } else {
424 /* everything fits in a header */
425 msgsize = sizeof(struct vmbus_channel_msginfo) +
426 sizeof(struct vmbus_channel_gpadl_header) +
427 sizeof(struct gpa_range) + pagecount * sizeof(u64);
428 msgheader = kzalloc(msgsize, GFP_KERNEL);
429 if (msgheader == NULL)
430 goto nomem;
431
432 INIT_LIST_HEAD(&msgheader->submsglist);
433 msgheader->msgsize = msgsize;
434
435 gpadl_header = (struct vmbus_channel_gpadl_header *)
436 msgheader->msg;
437 gpadl_header->rangecount = 1;
438 gpadl_header->range_buflen = sizeof(struct gpa_range) +
439 pagecount * sizeof(u64);
440 gpadl_header->range[0].byte_offset = 0;
441 gpadl_header->range[0].byte_count = size;
442 for (i = 0; i < pagecount; i++)
443 gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
444 kbuffer + PAGE_SIZE * i);
445
446 *msginfo = msgheader;
447 }
448
449 return 0;
450nomem:
451 kfree(msgheader);
452 kfree(msgbody);
453 return -ENOMEM;
454}
455
456/*
457 * vmbus_establish_gpadl - Establish a GPADL for the specified buffer
458 *
459 * @channel: a channel
460 * @kbuffer: from kmalloc or vmalloc
461 * @size: page-size multiple
462 * @gpadl_handle: some funky thing
463 */
464int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
465 u32 size, u32 *gpadl_handle)
466{
467 struct vmbus_channel_gpadl_header *gpadlmsg;
468 struct vmbus_channel_gpadl_body *gpadl_body;
469 struct vmbus_channel_msginfo *msginfo = NULL;
470 struct vmbus_channel_msginfo *submsginfo, *tmp;
471 struct list_head *curr;
472 u32 next_gpadl_handle;
473 unsigned long flags;
474 int ret = 0;
475
476 next_gpadl_handle =
477 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
478
479 ret = create_gpadl_header(kbuffer, size, &msginfo);
480 if (ret)
481 return ret;
482
483 init_completion(&msginfo->waitevent);
484 msginfo->waiting_channel = channel;
485
486 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
487 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
488 gpadlmsg->child_relid = channel->offermsg.child_relid;
489 gpadlmsg->gpadl = next_gpadl_handle;
490
491
492 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
493 list_add_tail(&msginfo->msglistentry,
494 &vmbus_connection.chn_msg_list);
495
496 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
497
498 if (channel->rescind) {
499 ret = -ENODEV;
500 goto cleanup;
501 }
502
503 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
504 sizeof(*msginfo), true);
505
506 trace_vmbus_establish_gpadl_header(gpadlmsg, ret);
507
508 if (ret != 0)
509 goto cleanup;
510
511 list_for_each(curr, &msginfo->submsglist) {
512 submsginfo = (struct vmbus_channel_msginfo *)curr;
513 gpadl_body =
514 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
515
516 gpadl_body->header.msgtype =
517 CHANNELMSG_GPADL_BODY;
518 gpadl_body->gpadl = next_gpadl_handle;
519
520 ret = vmbus_post_msg(gpadl_body,
521 submsginfo->msgsize - sizeof(*submsginfo),
522 true);
523
524 trace_vmbus_establish_gpadl_body(gpadl_body, ret);
525
526 if (ret != 0)
527 goto cleanup;
528
529 }
530 wait_for_completion(&msginfo->waitevent);
531
532 if (msginfo->response.gpadl_created.creation_status != 0) {
533 pr_err("Failed to establish GPADL: err = 0x%x\n",
534 msginfo->response.gpadl_created.creation_status);
535
536 ret = -EDQUOT;
537 goto cleanup;
538 }
539
540 if (channel->rescind) {
541 ret = -ENODEV;
542 goto cleanup;
543 }
544
545 /* At this point, we received the gpadl created msg */
546 *gpadl_handle = gpadlmsg->gpadl;
547
548cleanup:
549 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
550 list_del(&msginfo->msglistentry);
551 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
552 list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
553 msglistentry) {
554 kfree(submsginfo);
555 }
556
557 kfree(msginfo);
558 return ret;
559}
560EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
561
562/*
563 * vmbus_teardown_gpadl -Teardown the specified GPADL handle
564 */
565int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
566{
567 struct vmbus_channel_gpadl_teardown *msg;
568 struct vmbus_channel_msginfo *info;
569 unsigned long flags;
570 int ret;
571
572 info = kmalloc(sizeof(*info) +
573 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
574 if (!info)
575 return -ENOMEM;
576
577 init_completion(&info->waitevent);
578 info->waiting_channel = channel;
579
580 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
581
582 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
583 msg->child_relid = channel->offermsg.child_relid;
584 msg->gpadl = gpadl_handle;
585
586 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
587 list_add_tail(&info->msglistentry,
588 &vmbus_connection.chn_msg_list);
589 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
590
591 if (channel->rescind)
592 goto post_msg_err;
593
594 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
595 true);
596
597 trace_vmbus_teardown_gpadl(msg, ret);
598
599 if (ret)
600 goto post_msg_err;
601
602 wait_for_completion(&info->waitevent);
603
604post_msg_err:
605 /*
606 * If the channel has been rescinded;
607 * we will be awakened by the rescind
608 * handler; set the error code to zero so we don't leak memory.
609 */
610 if (channel->rescind)
611 ret = 0;
612
613 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
614 list_del(&info->msglistentry);
615 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
616
617 kfree(info);
618 return ret;
619}
620EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
621
622void vmbus_reset_channel_cb(struct vmbus_channel *channel)
623{
624 unsigned long flags;
625
626 /*
627 * vmbus_on_event(), running in the per-channel tasklet, can race
628 * with vmbus_close_internal() in the case of SMP guest, e.g., when
629 * the former is accessing channel->inbound.ring_buffer, the latter
630 * could be freeing the ring_buffer pages, so here we must stop it
631 * first.
632 *
633 * vmbus_chan_sched() might call the netvsc driver callback function
634 * that ends up scheduling NAPI work that accesses the ring buffer.
635 * At this point, we have to ensure that any such work is completed
636 * and that the channel ring buffer is no longer being accessed, cf.
637 * the calls to napi_disable() in netvsc_device_remove().
638 */
639 tasklet_disable(&channel->callback_event);
640
641 /* See the inline comments in vmbus_chan_sched(). */
642 spin_lock_irqsave(&channel->sched_lock, flags);
643 channel->onchannel_callback = NULL;
644 spin_unlock_irqrestore(&channel->sched_lock, flags);
645
646 channel->sc_creation_callback = NULL;
647
648 /* Re-enable tasklet for use on re-open */
649 tasklet_enable(&channel->callback_event);
650}
651
652static int vmbus_close_internal(struct vmbus_channel *channel)
653{
654 struct vmbus_channel_close_channel *msg;
655 int ret;
656
657 vmbus_reset_channel_cb(channel);
658
659 /*
660 * In case a device driver's probe() fails (e.g.,
661 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
662 * rescinded later (e.g., we dynamically disable an Integrated Service
663 * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
664 * here we should skip most of the below cleanup work.
665 */
666 if (channel->state != CHANNEL_OPENED_STATE)
667 return -EINVAL;
668
669 channel->state = CHANNEL_OPEN_STATE;
670
671 /* Send a closing message */
672
673 msg = &channel->close_msg.msg;
674
675 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
676 msg->child_relid = channel->offermsg.child_relid;
677
678 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel),
679 true);
680
681 trace_vmbus_close_internal(msg, ret);
682
683 if (ret) {
684 pr_err("Close failed: close post msg return is %d\n", ret);
685 /*
686 * If we failed to post the close msg,
687 * it is perhaps better to leak memory.
688 */
689 }
690
691 /* Tear down the gpadl for the channel's ring buffer */
692 else if (channel->ringbuffer_gpadlhandle) {
693 ret = vmbus_teardown_gpadl(channel,
694 channel->ringbuffer_gpadlhandle);
695 if (ret) {
696 pr_err("Close failed: teardown gpadl return %d\n", ret);
697 /*
698 * If we failed to teardown gpadl,
699 * it is perhaps better to leak memory.
700 */
701 }
702
703 channel->ringbuffer_gpadlhandle = 0;
704 }
705
706 return ret;
707}
708
709/* disconnect ring - close all channels */
710int vmbus_disconnect_ring(struct vmbus_channel *channel)
711{
712 struct vmbus_channel *cur_channel, *tmp;
713 int ret;
714
715 if (channel->primary_channel != NULL)
716 return -EINVAL;
717
718 list_for_each_entry_safe(cur_channel, tmp, &channel->sc_list, sc_list) {
719 if (cur_channel->rescind)
720 wait_for_completion(&cur_channel->rescind_event);
721
722 mutex_lock(&vmbus_connection.channel_mutex);
723 if (vmbus_close_internal(cur_channel) == 0) {
724 vmbus_free_ring(cur_channel);
725
726 if (cur_channel->rescind)
727 hv_process_channel_removal(cur_channel);
728 }
729 mutex_unlock(&vmbus_connection.channel_mutex);
730 }
731
732 /*
733 * Now close the primary.
734 */
735 mutex_lock(&vmbus_connection.channel_mutex);
736 ret = vmbus_close_internal(channel);
737 mutex_unlock(&vmbus_connection.channel_mutex);
738
739 return ret;
740}
741EXPORT_SYMBOL_GPL(vmbus_disconnect_ring);
742
743/*
744 * vmbus_close - Close the specified channel
745 */
746void vmbus_close(struct vmbus_channel *channel)
747{
748 if (vmbus_disconnect_ring(channel) == 0)
749 vmbus_free_ring(channel);
750}
751EXPORT_SYMBOL_GPL(vmbus_close);
752
753/**
754 * vmbus_sendpacket() - Send the specified buffer on the given channel
755 * @channel: Pointer to vmbus_channel structure
756 * @buffer: Pointer to the buffer you want to send the data from.
757 * @bufferlen: Maximum size of what the buffer holds.
758 * @requestid: Identifier of the request
759 * @type: Type of packet that is being sent e.g. negotiate, time
760 * packet etc.
761 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
762 *
763 * Sends data in @buffer directly to Hyper-V via the vmbus.
764 * This will send the data unparsed to Hyper-V.
765 *
766 * Mainly used by Hyper-V drivers.
767 */
768int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
769 u32 bufferlen, u64 requestid,
770 enum vmbus_packet_type type, u32 flags)
771{
772 struct vmpacket_descriptor desc;
773 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
774 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
775 struct kvec bufferlist[3];
776 u64 aligned_data = 0;
777 int num_vecs = ((bufferlen != 0) ? 3 : 1);
778
779
780 /* Setup the descriptor */
781 desc.type = type; /* VmbusPacketTypeDataInBand; */
782 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
783 /* in 8-bytes granularity */
784 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
785 desc.len8 = (u16)(packetlen_aligned >> 3);
786 desc.trans_id = requestid;
787
788 bufferlist[0].iov_base = &desc;
789 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
790 bufferlist[1].iov_base = buffer;
791 bufferlist[1].iov_len = bufferlen;
792 bufferlist[2].iov_base = &aligned_data;
793 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
794
795 return hv_ringbuffer_write(channel, bufferlist, num_vecs);
796}
797EXPORT_SYMBOL(vmbus_sendpacket);
798
799/*
800 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
801 * packets using a GPADL Direct packet type. This interface allows you
802 * to control notifying the host. This will be useful for sending
803 * batched data. Also the sender can control the send flags
804 * explicitly.
805 */
806int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
807 struct hv_page_buffer pagebuffers[],
808 u32 pagecount, void *buffer, u32 bufferlen,
809 u64 requestid)
810{
811 int i;
812 struct vmbus_channel_packet_page_buffer desc;
813 u32 descsize;
814 u32 packetlen;
815 u32 packetlen_aligned;
816 struct kvec bufferlist[3];
817 u64 aligned_data = 0;
818
819 if (pagecount > MAX_PAGE_BUFFER_COUNT)
820 return -EINVAL;
821
822 /*
823 * Adjust the size down since vmbus_channel_packet_page_buffer is the
824 * largest size we support
825 */
826 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
827 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
828 sizeof(struct hv_page_buffer));
829 packetlen = descsize + bufferlen;
830 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
831
832 /* Setup the descriptor */
833 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
834 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
835 desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
836 desc.length8 = (u16)(packetlen_aligned >> 3);
837 desc.transactionid = requestid;
838 desc.reserved = 0;
839 desc.rangecount = pagecount;
840
841 for (i = 0; i < pagecount; i++) {
842 desc.range[i].len = pagebuffers[i].len;
843 desc.range[i].offset = pagebuffers[i].offset;
844 desc.range[i].pfn = pagebuffers[i].pfn;
845 }
846
847 bufferlist[0].iov_base = &desc;
848 bufferlist[0].iov_len = descsize;
849 bufferlist[1].iov_base = buffer;
850 bufferlist[1].iov_len = bufferlen;
851 bufferlist[2].iov_base = &aligned_data;
852 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
853
854 return hv_ringbuffer_write(channel, bufferlist, 3);
855}
856EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
857
858/*
859 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
860 * using a GPADL Direct packet type.
861 * The buffer includes the vmbus descriptor.
862 */
863int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
864 struct vmbus_packet_mpb_array *desc,
865 u32 desc_size,
866 void *buffer, u32 bufferlen, u64 requestid)
867{
868 u32 packetlen;
869 u32 packetlen_aligned;
870 struct kvec bufferlist[3];
871 u64 aligned_data = 0;
872
873 packetlen = desc_size + bufferlen;
874 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
875
876 /* Setup the descriptor */
877 desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
878 desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
879 desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */
880 desc->length8 = (u16)(packetlen_aligned >> 3);
881 desc->transactionid = requestid;
882 desc->reserved = 0;
883 desc->rangecount = 1;
884
885 bufferlist[0].iov_base = desc;
886 bufferlist[0].iov_len = desc_size;
887 bufferlist[1].iov_base = buffer;
888 bufferlist[1].iov_len = bufferlen;
889 bufferlist[2].iov_base = &aligned_data;
890 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
891
892 return hv_ringbuffer_write(channel, bufferlist, 3);
893}
894EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
895
896/**
897 * __vmbus_recvpacket() - Retrieve the user packet on the specified channel
898 * @channel: Pointer to vmbus_channel structure
899 * @buffer: Pointer to the buffer you want to receive the data into.
900 * @bufferlen: Maximum size of what the buffer can hold.
901 * @buffer_actual_len: The actual size of the data after it was received.
902 * @requestid: Identifier of the request
903 * @raw: true means keep the vmpacket_descriptor header in the received data.
904 *
905 * Receives directly from the hyper-v vmbus and puts the data it received
906 * into Buffer. This will receive the data unparsed from hyper-v.
907 *
908 * Mainly used by Hyper-V drivers.
909 */
910static inline int
911__vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
912 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
913 bool raw)
914{
915 return hv_ringbuffer_read(channel, buffer, bufferlen,
916 buffer_actual_len, requestid, raw);
917
918}
919
920int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
921 u32 bufferlen, u32 *buffer_actual_len,
922 u64 *requestid)
923{
924 return __vmbus_recvpacket(channel, buffer, bufferlen,
925 buffer_actual_len, requestid, false);
926}
927EXPORT_SYMBOL(vmbus_recvpacket);
928
929/*
930 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
931 */
932int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
933 u32 bufferlen, u32 *buffer_actual_len,
934 u64 *requestid)
935{
936 return __vmbus_recvpacket(channel, buffer, bufferlen,
937 buffer_actual_len, requestid, true);
938}
939EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
1/*
2 * Copyright (c) 2009, Microsoft Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
16 *
17 * Authors:
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
20 */
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/kernel.h>
24#include <linux/sched.h>
25#include <linux/wait.h>
26#include <linux/mm.h>
27#include <linux/slab.h>
28#include <linux/module.h>
29#include <linux/hyperv.h>
30#include <linux/uio.h>
31#include <linux/interrupt.h>
32
33#include "hyperv_vmbus.h"
34
35#define NUM_PAGES_SPANNED(addr, len) \
36((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
37
38/*
39 * vmbus_setevent- Trigger an event notification on the specified
40 * channel.
41 */
42void vmbus_setevent(struct vmbus_channel *channel)
43{
44 struct hv_monitor_page *monitorpage;
45
46 /*
47 * For channels marked as in "low latency" mode
48 * bypass the monitor page mechanism.
49 */
50 if ((channel->offermsg.monitor_allocated) &&
51 (!channel->low_latency)) {
52 /* Each u32 represents 32 channels */
53 sync_set_bit(channel->offermsg.child_relid & 31,
54 (unsigned long *) vmbus_connection.send_int_page +
55 (channel->offermsg.child_relid >> 5));
56
57 /* Get the child to parent monitor page */
58 monitorpage = vmbus_connection.monitor_pages[1];
59
60 sync_set_bit(channel->monitor_bit,
61 (unsigned long *)&monitorpage->trigger_group
62 [channel->monitor_grp].pending);
63
64 } else {
65 vmbus_set_event(channel);
66 }
67}
68EXPORT_SYMBOL_GPL(vmbus_setevent);
69
70/*
71 * vmbus_open - Open the specified channel.
72 */
73int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
74 u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
75 void (*onchannelcallback)(void *context), void *context)
76{
77 struct vmbus_channel_open_channel *open_msg;
78 struct vmbus_channel_msginfo *open_info = NULL;
79 unsigned long flags;
80 int ret, err = 0;
81 struct page *page;
82
83 if (send_ringbuffer_size % PAGE_SIZE ||
84 recv_ringbuffer_size % PAGE_SIZE)
85 return -EINVAL;
86
87 spin_lock_irqsave(&newchannel->lock, flags);
88 if (newchannel->state == CHANNEL_OPEN_STATE) {
89 newchannel->state = CHANNEL_OPENING_STATE;
90 } else {
91 spin_unlock_irqrestore(&newchannel->lock, flags);
92 return -EINVAL;
93 }
94 spin_unlock_irqrestore(&newchannel->lock, flags);
95
96 newchannel->onchannel_callback = onchannelcallback;
97 newchannel->channel_callback_context = context;
98
99 /* Allocate the ring buffer */
100 page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
101 GFP_KERNEL|__GFP_ZERO,
102 get_order(send_ringbuffer_size +
103 recv_ringbuffer_size));
104
105 if (!page)
106 page = alloc_pages(GFP_KERNEL|__GFP_ZERO,
107 get_order(send_ringbuffer_size +
108 recv_ringbuffer_size));
109
110 if (!page) {
111 err = -ENOMEM;
112 goto error_set_chnstate;
113 }
114
115 newchannel->ringbuffer_pages = page_address(page);
116 newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
117 recv_ringbuffer_size) >> PAGE_SHIFT;
118
119 ret = hv_ringbuffer_init(&newchannel->outbound, page,
120 send_ringbuffer_size >> PAGE_SHIFT);
121
122 if (ret != 0) {
123 err = ret;
124 goto error_free_pages;
125 }
126
127 ret = hv_ringbuffer_init(&newchannel->inbound,
128 &page[send_ringbuffer_size >> PAGE_SHIFT],
129 recv_ringbuffer_size >> PAGE_SHIFT);
130 if (ret != 0) {
131 err = ret;
132 goto error_free_pages;
133 }
134
135
136 /* Establish the gpadl for the ring buffer */
137 newchannel->ringbuffer_gpadlhandle = 0;
138
139 ret = vmbus_establish_gpadl(newchannel,
140 page_address(page),
141 send_ringbuffer_size +
142 recv_ringbuffer_size,
143 &newchannel->ringbuffer_gpadlhandle);
144
145 if (ret != 0) {
146 err = ret;
147 goto error_free_pages;
148 }
149
150 /* Create and init the channel open message */
151 open_info = kmalloc(sizeof(*open_info) +
152 sizeof(struct vmbus_channel_open_channel),
153 GFP_KERNEL);
154 if (!open_info) {
155 err = -ENOMEM;
156 goto error_free_gpadl;
157 }
158
159 init_completion(&open_info->waitevent);
160 open_info->waiting_channel = newchannel;
161
162 open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
163 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
164 open_msg->openid = newchannel->offermsg.child_relid;
165 open_msg->child_relid = newchannel->offermsg.child_relid;
166 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
167 open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
168 PAGE_SHIFT;
169 open_msg->target_vp = newchannel->target_vp;
170
171 if (userdatalen > MAX_USER_DEFINED_BYTES) {
172 err = -EINVAL;
173 goto error_free_gpadl;
174 }
175
176 if (userdatalen)
177 memcpy(open_msg->userdata, userdata, userdatalen);
178
179 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
180 list_add_tail(&open_info->msglistentry,
181 &vmbus_connection.chn_msg_list);
182 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
183
184 ret = vmbus_post_msg(open_msg,
185 sizeof(struct vmbus_channel_open_channel), true);
186
187 if (ret != 0) {
188 err = ret;
189 goto error_clean_msglist;
190 }
191
192 wait_for_completion(&open_info->waitevent);
193
194 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
195 list_del(&open_info->msglistentry);
196 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
197
198 if (newchannel->rescind) {
199 err = -ENODEV;
200 goto error_free_gpadl;
201 }
202
203 if (open_info->response.open_result.status) {
204 err = -EAGAIN;
205 goto error_free_gpadl;
206 }
207
208 newchannel->state = CHANNEL_OPENED_STATE;
209 kfree(open_info);
210 return 0;
211
212error_clean_msglist:
213 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
214 list_del(&open_info->msglistentry);
215 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
216
217error_free_gpadl:
218 vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
219 kfree(open_info);
220error_free_pages:
221 hv_ringbuffer_cleanup(&newchannel->outbound);
222 hv_ringbuffer_cleanup(&newchannel->inbound);
223 __free_pages(page,
224 get_order(send_ringbuffer_size + recv_ringbuffer_size));
225error_set_chnstate:
226 newchannel->state = CHANNEL_OPEN_STATE;
227 return err;
228}
229EXPORT_SYMBOL_GPL(vmbus_open);
230
231/* Used for Hyper-V Socket: a guest client's connect() to the host */
232int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
233 const uuid_le *shv_host_servie_id)
234{
235 struct vmbus_channel_tl_connect_request conn_msg;
236
237 memset(&conn_msg, 0, sizeof(conn_msg));
238 conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
239 conn_msg.guest_endpoint_id = *shv_guest_servie_id;
240 conn_msg.host_service_id = *shv_host_servie_id;
241
242 return vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
243}
244EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
245
246/*
247 * create_gpadl_header - Creates a gpadl for the specified buffer
248 */
249static int create_gpadl_header(void *kbuffer, u32 size,
250 struct vmbus_channel_msginfo **msginfo)
251{
252 int i;
253 int pagecount;
254 struct vmbus_channel_gpadl_header *gpadl_header;
255 struct vmbus_channel_gpadl_body *gpadl_body;
256 struct vmbus_channel_msginfo *msgheader;
257 struct vmbus_channel_msginfo *msgbody = NULL;
258 u32 msgsize;
259
260 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
261
262 pagecount = size >> PAGE_SHIFT;
263
264 /* do we need a gpadl body msg */
265 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
266 sizeof(struct vmbus_channel_gpadl_header) -
267 sizeof(struct gpa_range);
268 pfncount = pfnsize / sizeof(u64);
269
270 if (pagecount > pfncount) {
271 /* we need a gpadl body */
272 /* fill in the header */
273 msgsize = sizeof(struct vmbus_channel_msginfo) +
274 sizeof(struct vmbus_channel_gpadl_header) +
275 sizeof(struct gpa_range) + pfncount * sizeof(u64);
276 msgheader = kzalloc(msgsize, GFP_KERNEL);
277 if (!msgheader)
278 goto nomem;
279
280 INIT_LIST_HEAD(&msgheader->submsglist);
281 msgheader->msgsize = msgsize;
282
283 gpadl_header = (struct vmbus_channel_gpadl_header *)
284 msgheader->msg;
285 gpadl_header->rangecount = 1;
286 gpadl_header->range_buflen = sizeof(struct gpa_range) +
287 pagecount * sizeof(u64);
288 gpadl_header->range[0].byte_offset = 0;
289 gpadl_header->range[0].byte_count = size;
290 for (i = 0; i < pfncount; i++)
291 gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
292 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
293 *msginfo = msgheader;
294
295 pfnsum = pfncount;
296 pfnleft = pagecount - pfncount;
297
298 /* how many pfns can we fit */
299 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
300 sizeof(struct vmbus_channel_gpadl_body);
301 pfncount = pfnsize / sizeof(u64);
302
303 /* fill in the body */
304 while (pfnleft) {
305 if (pfnleft > pfncount)
306 pfncurr = pfncount;
307 else
308 pfncurr = pfnleft;
309
310 msgsize = sizeof(struct vmbus_channel_msginfo) +
311 sizeof(struct vmbus_channel_gpadl_body) +
312 pfncurr * sizeof(u64);
313 msgbody = kzalloc(msgsize, GFP_KERNEL);
314
315 if (!msgbody) {
316 struct vmbus_channel_msginfo *pos = NULL;
317 struct vmbus_channel_msginfo *tmp = NULL;
318 /*
319 * Free up all the allocated messages.
320 */
321 list_for_each_entry_safe(pos, tmp,
322 &msgheader->submsglist,
323 msglistentry) {
324
325 list_del(&pos->msglistentry);
326 kfree(pos);
327 }
328
329 goto nomem;
330 }
331
332 msgbody->msgsize = msgsize;
333 gpadl_body =
334 (struct vmbus_channel_gpadl_body *)msgbody->msg;
335
336 /*
337 * Gpadl is u32 and we are using a pointer which could
338 * be 64-bit
339 * This is governed by the guest/host protocol and
340 * so the hypervisor gurantees that this is ok.
341 */
342 for (i = 0; i < pfncurr; i++)
343 gpadl_body->pfn[i] = slow_virt_to_phys(
344 kbuffer + PAGE_SIZE * (pfnsum + i)) >>
345 PAGE_SHIFT;
346
347 /* add to msg header */
348 list_add_tail(&msgbody->msglistentry,
349 &msgheader->submsglist);
350 pfnsum += pfncurr;
351 pfnleft -= pfncurr;
352 }
353 } else {
354 /* everything fits in a header */
355 msgsize = sizeof(struct vmbus_channel_msginfo) +
356 sizeof(struct vmbus_channel_gpadl_header) +
357 sizeof(struct gpa_range) + pagecount * sizeof(u64);
358 msgheader = kzalloc(msgsize, GFP_KERNEL);
359 if (msgheader == NULL)
360 goto nomem;
361
362 INIT_LIST_HEAD(&msgheader->submsglist);
363 msgheader->msgsize = msgsize;
364
365 gpadl_header = (struct vmbus_channel_gpadl_header *)
366 msgheader->msg;
367 gpadl_header->rangecount = 1;
368 gpadl_header->range_buflen = sizeof(struct gpa_range) +
369 pagecount * sizeof(u64);
370 gpadl_header->range[0].byte_offset = 0;
371 gpadl_header->range[0].byte_count = size;
372 for (i = 0; i < pagecount; i++)
373 gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
374 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
375
376 *msginfo = msgheader;
377 }
378
379 return 0;
380nomem:
381 kfree(msgheader);
382 kfree(msgbody);
383 return -ENOMEM;
384}
385
386/*
387 * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
388 *
389 * @channel: a channel
390 * @kbuffer: from kmalloc or vmalloc
391 * @size: page-size multiple
392 * @gpadl_handle: some funky thing
393 */
394int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
395 u32 size, u32 *gpadl_handle)
396{
397 struct vmbus_channel_gpadl_header *gpadlmsg;
398 struct vmbus_channel_gpadl_body *gpadl_body;
399 struct vmbus_channel_msginfo *msginfo = NULL;
400 struct vmbus_channel_msginfo *submsginfo, *tmp;
401 struct list_head *curr;
402 u32 next_gpadl_handle;
403 unsigned long flags;
404 int ret = 0;
405
406 next_gpadl_handle =
407 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
408
409 ret = create_gpadl_header(kbuffer, size, &msginfo);
410 if (ret)
411 return ret;
412
413 init_completion(&msginfo->waitevent);
414 msginfo->waiting_channel = channel;
415
416 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
417 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
418 gpadlmsg->child_relid = channel->offermsg.child_relid;
419 gpadlmsg->gpadl = next_gpadl_handle;
420
421
422 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
423 list_add_tail(&msginfo->msglistentry,
424 &vmbus_connection.chn_msg_list);
425
426 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
427
428 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
429 sizeof(*msginfo), true);
430 if (ret != 0)
431 goto cleanup;
432
433 list_for_each(curr, &msginfo->submsglist) {
434 submsginfo = (struct vmbus_channel_msginfo *)curr;
435 gpadl_body =
436 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
437
438 gpadl_body->header.msgtype =
439 CHANNELMSG_GPADL_BODY;
440 gpadl_body->gpadl = next_gpadl_handle;
441
442 ret = vmbus_post_msg(gpadl_body,
443 submsginfo->msgsize - sizeof(*submsginfo),
444 true);
445 if (ret != 0)
446 goto cleanup;
447
448 }
449 wait_for_completion(&msginfo->waitevent);
450
451 if (channel->rescind) {
452 ret = -ENODEV;
453 goto cleanup;
454 }
455
456 /* At this point, we received the gpadl created msg */
457 *gpadl_handle = gpadlmsg->gpadl;
458
459cleanup:
460 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
461 list_del(&msginfo->msglistentry);
462 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
463 list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
464 msglistentry) {
465 kfree(submsginfo);
466 }
467
468 kfree(msginfo);
469 return ret;
470}
471EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
472
473/*
474 * vmbus_teardown_gpadl -Teardown the specified GPADL handle
475 */
476int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
477{
478 struct vmbus_channel_gpadl_teardown *msg;
479 struct vmbus_channel_msginfo *info;
480 unsigned long flags;
481 int ret;
482
483 info = kmalloc(sizeof(*info) +
484 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
485 if (!info)
486 return -ENOMEM;
487
488 init_completion(&info->waitevent);
489 info->waiting_channel = channel;
490
491 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
492
493 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
494 msg->child_relid = channel->offermsg.child_relid;
495 msg->gpadl = gpadl_handle;
496
497 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
498 list_add_tail(&info->msglistentry,
499 &vmbus_connection.chn_msg_list);
500 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
501 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
502 true);
503
504 if (ret)
505 goto post_msg_err;
506
507 wait_for_completion(&info->waitevent);
508
509post_msg_err:
510 /*
511 * If the channel has been rescinded;
512 * we will be awakened by the rescind
513 * handler; set the error code to zero so we don't leak memory.
514 */
515 if (channel->rescind)
516 ret = 0;
517
518 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
519 list_del(&info->msglistentry);
520 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
521
522 kfree(info);
523 return ret;
524}
525EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
526
527static void reset_channel_cb(void *arg)
528{
529 struct vmbus_channel *channel = arg;
530
531 channel->onchannel_callback = NULL;
532}
533
534static int vmbus_close_internal(struct vmbus_channel *channel)
535{
536 struct vmbus_channel_close_channel *msg;
537 int ret;
538
539 /*
540 * process_chn_event(), running in the tasklet, can race
541 * with vmbus_close_internal() in the case of SMP guest, e.g., when
542 * the former is accessing channel->inbound.ring_buffer, the latter
543 * could be freeing the ring_buffer pages.
544 *
545 * To resolve the race, we can serialize them by disabling the
546 * tasklet when the latter is running here.
547 */
548 hv_event_tasklet_disable(channel);
549
550 /*
551 * In case a device driver's probe() fails (e.g.,
552 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
553 * rescinded later (e.g., we dynamically disble an Integrated Service
554 * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
555 * here we should skip most of the below cleanup work.
556 */
557 if (channel->state != CHANNEL_OPENED_STATE) {
558 ret = -EINVAL;
559 goto out;
560 }
561
562 channel->state = CHANNEL_OPEN_STATE;
563 channel->sc_creation_callback = NULL;
564 /* Stop callback and cancel the timer asap */
565 if (channel->target_cpu != get_cpu()) {
566 put_cpu();
567 smp_call_function_single(channel->target_cpu, reset_channel_cb,
568 channel, true);
569 } else {
570 reset_channel_cb(channel);
571 put_cpu();
572 }
573
574 /* Send a closing message */
575
576 msg = &channel->close_msg.msg;
577
578 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
579 msg->child_relid = channel->offermsg.child_relid;
580
581 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel),
582 true);
583
584 if (ret) {
585 pr_err("Close failed: close post msg return is %d\n", ret);
586 /*
587 * If we failed to post the close msg,
588 * it is perhaps better to leak memory.
589 */
590 goto out;
591 }
592
593 /* Tear down the gpadl for the channel's ring buffer */
594 if (channel->ringbuffer_gpadlhandle) {
595 ret = vmbus_teardown_gpadl(channel,
596 channel->ringbuffer_gpadlhandle);
597 if (ret) {
598 pr_err("Close failed: teardown gpadl return %d\n", ret);
599 /*
600 * If we failed to teardown gpadl,
601 * it is perhaps better to leak memory.
602 */
603 goto out;
604 }
605 }
606
607 /* Cleanup the ring buffers for this channel */
608 hv_ringbuffer_cleanup(&channel->outbound);
609 hv_ringbuffer_cleanup(&channel->inbound);
610
611 free_pages((unsigned long)channel->ringbuffer_pages,
612 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
613
614out:
615 hv_event_tasklet_enable(channel);
616
617 return ret;
618}
619
620/*
621 * vmbus_close - Close the specified channel
622 */
623void vmbus_close(struct vmbus_channel *channel)
624{
625 struct list_head *cur, *tmp;
626 struct vmbus_channel *cur_channel;
627
628 if (channel->primary_channel != NULL) {
629 /*
630 * We will only close sub-channels when
631 * the primary is closed.
632 */
633 return;
634 }
635 /*
636 * Close all the sub-channels first and then close the
637 * primary channel.
638 */
639 list_for_each_safe(cur, tmp, &channel->sc_list) {
640 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
641 if (cur_channel->state != CHANNEL_OPENED_STATE)
642 continue;
643 vmbus_close_internal(cur_channel);
644 }
645 /*
646 * Now close the primary.
647 */
648 vmbus_close_internal(channel);
649}
650EXPORT_SYMBOL_GPL(vmbus_close);
651
652int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
653 u32 bufferlen, u64 requestid,
654 enum vmbus_packet_type type, u32 flags, bool kick_q)
655{
656 struct vmpacket_descriptor desc;
657 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
658 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
659 struct kvec bufferlist[3];
660 u64 aligned_data = 0;
661 bool lock = channel->acquire_ring_lock;
662 int num_vecs = ((bufferlen != 0) ? 3 : 1);
663
664
665 /* Setup the descriptor */
666 desc.type = type; /* VmbusPacketTypeDataInBand; */
667 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
668 /* in 8-bytes granularity */
669 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
670 desc.len8 = (u16)(packetlen_aligned >> 3);
671 desc.trans_id = requestid;
672
673 bufferlist[0].iov_base = &desc;
674 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
675 bufferlist[1].iov_base = buffer;
676 bufferlist[1].iov_len = bufferlen;
677 bufferlist[2].iov_base = &aligned_data;
678 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
679
680 return hv_ringbuffer_write(channel, bufferlist, num_vecs,
681 lock, kick_q);
682
683}
684EXPORT_SYMBOL(vmbus_sendpacket_ctl);
685
686/**
687 * vmbus_sendpacket() - Send the specified buffer on the given channel
688 * @channel: Pointer to vmbus_channel structure.
689 * @buffer: Pointer to the buffer you want to receive the data into.
690 * @bufferlen: Maximum size of what the the buffer will hold
691 * @requestid: Identifier of the request
692 * @type: Type of packet that is being send e.g. negotiate, time
693 * packet etc.
694 *
695 * Sends data in @buffer directly to hyper-v via the vmbus
696 * This will send the data unparsed to hyper-v.
697 *
698 * Mainly used by Hyper-V drivers.
699 */
700int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
701 u32 bufferlen, u64 requestid,
702 enum vmbus_packet_type type, u32 flags)
703{
704 return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
705 type, flags, true);
706}
707EXPORT_SYMBOL(vmbus_sendpacket);
708
709/*
710 * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
711 * packets using a GPADL Direct packet type. This interface allows you
712 * to control notifying the host. This will be useful for sending
713 * batched data. Also the sender can control the send flags
714 * explicitly.
715 */
716int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
717 struct hv_page_buffer pagebuffers[],
718 u32 pagecount, void *buffer, u32 bufferlen,
719 u64 requestid,
720 u32 flags,
721 bool kick_q)
722{
723 int i;
724 struct vmbus_channel_packet_page_buffer desc;
725 u32 descsize;
726 u32 packetlen;
727 u32 packetlen_aligned;
728 struct kvec bufferlist[3];
729 u64 aligned_data = 0;
730 bool lock = channel->acquire_ring_lock;
731
732 if (pagecount > MAX_PAGE_BUFFER_COUNT)
733 return -EINVAL;
734
735
736 /*
737 * Adjust the size down since vmbus_channel_packet_page_buffer is the
738 * largest size we support
739 */
740 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
741 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
742 sizeof(struct hv_page_buffer));
743 packetlen = descsize + bufferlen;
744 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
745
746 /* Setup the descriptor */
747 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
748 desc.flags = flags;
749 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
750 desc.length8 = (u16)(packetlen_aligned >> 3);
751 desc.transactionid = requestid;
752 desc.rangecount = pagecount;
753
754 for (i = 0; i < pagecount; i++) {
755 desc.range[i].len = pagebuffers[i].len;
756 desc.range[i].offset = pagebuffers[i].offset;
757 desc.range[i].pfn = pagebuffers[i].pfn;
758 }
759
760 bufferlist[0].iov_base = &desc;
761 bufferlist[0].iov_len = descsize;
762 bufferlist[1].iov_base = buffer;
763 bufferlist[1].iov_len = bufferlen;
764 bufferlist[2].iov_base = &aligned_data;
765 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
766
767 return hv_ringbuffer_write(channel, bufferlist, 3,
768 lock, kick_q);
769}
770EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
771
772/*
773 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
774 * packets using a GPADL Direct packet type.
775 */
776int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
777 struct hv_page_buffer pagebuffers[],
778 u32 pagecount, void *buffer, u32 bufferlen,
779 u64 requestid)
780{
781 u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
782 return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
783 buffer, bufferlen, requestid,
784 flags, true);
785
786}
787EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
788
789/*
790 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
791 * using a GPADL Direct packet type.
792 * The buffer includes the vmbus descriptor.
793 */
794int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
795 struct vmbus_packet_mpb_array *desc,
796 u32 desc_size,
797 void *buffer, u32 bufferlen, u64 requestid)
798{
799 u32 packetlen;
800 u32 packetlen_aligned;
801 struct kvec bufferlist[3];
802 u64 aligned_data = 0;
803 bool lock = channel->acquire_ring_lock;
804
805 packetlen = desc_size + bufferlen;
806 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
807
808 /* Setup the descriptor */
809 desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
810 desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
811 desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
812 desc->length8 = (u16)(packetlen_aligned >> 3);
813 desc->transactionid = requestid;
814 desc->rangecount = 1;
815
816 bufferlist[0].iov_base = desc;
817 bufferlist[0].iov_len = desc_size;
818 bufferlist[1].iov_base = buffer;
819 bufferlist[1].iov_len = bufferlen;
820 bufferlist[2].iov_base = &aligned_data;
821 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
822
823 return hv_ringbuffer_write(channel, bufferlist, 3,
824 lock, true);
825}
826EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
827
828/*
829 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
830 * using a GPADL Direct packet type.
831 */
832int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
833 struct hv_multipage_buffer *multi_pagebuffer,
834 void *buffer, u32 bufferlen, u64 requestid)
835{
836 struct vmbus_channel_packet_multipage_buffer desc;
837 u32 descsize;
838 u32 packetlen;
839 u32 packetlen_aligned;
840 struct kvec bufferlist[3];
841 u64 aligned_data = 0;
842 bool lock = channel->acquire_ring_lock;
843 u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
844 multi_pagebuffer->len);
845
846 if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
847 return -EINVAL;
848
849 /*
850 * Adjust the size down since vmbus_channel_packet_multipage_buffer is
851 * the largest size we support
852 */
853 descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
854 ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
855 sizeof(u64));
856 packetlen = descsize + bufferlen;
857 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
858
859
860 /* Setup the descriptor */
861 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
862 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
863 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
864 desc.length8 = (u16)(packetlen_aligned >> 3);
865 desc.transactionid = requestid;
866 desc.rangecount = 1;
867
868 desc.range.len = multi_pagebuffer->len;
869 desc.range.offset = multi_pagebuffer->offset;
870
871 memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
872 pfncount * sizeof(u64));
873
874 bufferlist[0].iov_base = &desc;
875 bufferlist[0].iov_len = descsize;
876 bufferlist[1].iov_base = buffer;
877 bufferlist[1].iov_len = bufferlen;
878 bufferlist[2].iov_base = &aligned_data;
879 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
880
881 return hv_ringbuffer_write(channel, bufferlist, 3,
882 lock, true);
883}
884EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
885
886/**
887 * vmbus_recvpacket() - Retrieve the user packet on the specified channel
888 * @channel: Pointer to vmbus_channel structure.
889 * @buffer: Pointer to the buffer you want to receive the data into.
890 * @bufferlen: Maximum size of what the the buffer will hold
891 * @buffer_actual_len: The actual size of the data after it was received
892 * @requestid: Identifier of the request
893 *
894 * Receives directly from the hyper-v vmbus and puts the data it received
895 * into Buffer. This will receive the data unparsed from hyper-v.
896 *
897 * Mainly used by Hyper-V drivers.
898 */
899static inline int
900__vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
901 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
902 bool raw)
903{
904 return hv_ringbuffer_read(channel, buffer, bufferlen,
905 buffer_actual_len, requestid, raw);
906
907}
908
909int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
910 u32 bufferlen, u32 *buffer_actual_len,
911 u64 *requestid)
912{
913 return __vmbus_recvpacket(channel, buffer, bufferlen,
914 buffer_actual_len, requestid, false);
915}
916EXPORT_SYMBOL(vmbus_recvpacket);
917
918/*
919 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
920 */
921int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
922 u32 bufferlen, u32 *buffer_actual_len,
923 u64 *requestid)
924{
925 return __vmbus_recvpacket(channel, buffer, bufferlen,
926 buffer_actual_len, requestid, true);
927}
928EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);