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[mirror_qemu.git] / hw / virtio / virtio.c
1 /*
2 * Virtio Support
3 *
4 * Copyright IBM, Corp. 2007
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 *
12 */
13
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "cpu.h"
17 #include "trace.h"
18 #include "exec/address-spaces.h"
19 #include "qemu/error-report.h"
20 #include "qemu/module.h"
21 #include "hw/virtio/virtio.h"
22 #include "qemu/atomic.h"
23 #include "hw/virtio/virtio-bus.h"
24 #include "hw/virtio/virtio-access.h"
25 #include "sysemu/dma.h"
26
27 /*
28 * The alignment to use between consumer and producer parts of vring.
29 * x86 pagesize again. This is the default, used by transports like PCI
30 * which don't provide a means for the guest to tell the host the alignment.
31 */
32 #define VIRTIO_PCI_VRING_ALIGN 4096
33
34 typedef struct VRingDesc
35 {
36 uint64_t addr;
37 uint32_t len;
38 uint16_t flags;
39 uint16_t next;
40 } VRingDesc;
41
42 typedef struct VRingAvail
43 {
44 uint16_t flags;
45 uint16_t idx;
46 uint16_t ring[0];
47 } VRingAvail;
48
49 typedef struct VRingUsedElem
50 {
51 uint32_t id;
52 uint32_t len;
53 } VRingUsedElem;
54
55 typedef struct VRingUsed
56 {
57 uint16_t flags;
58 uint16_t idx;
59 VRingUsedElem ring[0];
60 } VRingUsed;
61
62 typedef struct VRingMemoryRegionCaches {
63 struct rcu_head rcu;
64 MemoryRegionCache desc;
65 MemoryRegionCache avail;
66 MemoryRegionCache used;
67 } VRingMemoryRegionCaches;
68
69 typedef struct VRing
70 {
71 unsigned int num;
72 unsigned int num_default;
73 unsigned int align;
74 hwaddr desc;
75 hwaddr avail;
76 hwaddr used;
77 VRingMemoryRegionCaches *caches;
78 } VRing;
79
80 struct VirtQueue
81 {
82 VRing vring;
83
84 /* Next head to pop */
85 uint16_t last_avail_idx;
86
87 /* Last avail_idx read from VQ. */
88 uint16_t shadow_avail_idx;
89
90 uint16_t used_idx;
91
92 /* Last used index value we have signalled on */
93 uint16_t signalled_used;
94
95 /* Last used index value we have signalled on */
96 bool signalled_used_valid;
97
98 /* Notification enabled? */
99 bool notification;
100
101 uint16_t queue_index;
102
103 unsigned int inuse;
104
105 uint16_t vector;
106 VirtIOHandleOutput handle_output;
107 VirtIOHandleAIOOutput handle_aio_output;
108 VirtIODevice *vdev;
109 EventNotifier guest_notifier;
110 EventNotifier host_notifier;
111 QLIST_ENTRY(VirtQueue) node;
112 };
113
114 static void virtio_free_region_cache(VRingMemoryRegionCaches *caches)
115 {
116 if (!caches) {
117 return;
118 }
119
120 address_space_cache_destroy(&caches->desc);
121 address_space_cache_destroy(&caches->avail);
122 address_space_cache_destroy(&caches->used);
123 g_free(caches);
124 }
125
126 static void virtio_virtqueue_reset_region_cache(struct VirtQueue *vq)
127 {
128 VRingMemoryRegionCaches *caches;
129
130 caches = atomic_read(&vq->vring.caches);
131 atomic_rcu_set(&vq->vring.caches, NULL);
132 if (caches) {
133 call_rcu(caches, virtio_free_region_cache, rcu);
134 }
135 }
136
137 static void virtio_init_region_cache(VirtIODevice *vdev, int n)
138 {
139 VirtQueue *vq = &vdev->vq[n];
140 VRingMemoryRegionCaches *old = vq->vring.caches;
141 VRingMemoryRegionCaches *new = NULL;
142 hwaddr addr, size;
143 int event_size;
144 int64_t len;
145
146 event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
147
148 addr = vq->vring.desc;
149 if (!addr) {
150 goto out_no_cache;
151 }
152 new = g_new0(VRingMemoryRegionCaches, 1);
153 size = virtio_queue_get_desc_size(vdev, n);
154 len = address_space_cache_init(&new->desc, vdev->dma_as,
155 addr, size, false);
156 if (len < size) {
157 virtio_error(vdev, "Cannot map desc");
158 goto err_desc;
159 }
160
161 size = virtio_queue_get_used_size(vdev, n) + event_size;
162 len = address_space_cache_init(&new->used, vdev->dma_as,
163 vq->vring.used, size, true);
164 if (len < size) {
165 virtio_error(vdev, "Cannot map used");
166 goto err_used;
167 }
168
169 size = virtio_queue_get_avail_size(vdev, n) + event_size;
170 len = address_space_cache_init(&new->avail, vdev->dma_as,
171 vq->vring.avail, size, false);
172 if (len < size) {
173 virtio_error(vdev, "Cannot map avail");
174 goto err_avail;
175 }
176
177 atomic_rcu_set(&vq->vring.caches, new);
178 if (old) {
179 call_rcu(old, virtio_free_region_cache, rcu);
180 }
181 return;
182
183 err_avail:
184 address_space_cache_destroy(&new->avail);
185 err_used:
186 address_space_cache_destroy(&new->used);
187 err_desc:
188 address_space_cache_destroy(&new->desc);
189 out_no_cache:
190 g_free(new);
191 virtio_virtqueue_reset_region_cache(vq);
192 }
193
194 /* virt queue functions */
195 void virtio_queue_update_rings(VirtIODevice *vdev, int n)
196 {
197 VRing *vring = &vdev->vq[n].vring;
198
199 if (!vring->num || !vring->desc || !vring->align) {
200 /* not yet setup -> nothing to do */
201 return;
202 }
203 vring->avail = vring->desc + vring->num * sizeof(VRingDesc);
204 vring->used = vring_align(vring->avail +
205 offsetof(VRingAvail, ring[vring->num]),
206 vring->align);
207 virtio_init_region_cache(vdev, n);
208 }
209
210 /* Called within rcu_read_lock(). */
211 static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc,
212 MemoryRegionCache *cache, int i)
213 {
214 address_space_read_cached(cache, i * sizeof(VRingDesc),
215 desc, sizeof(VRingDesc));
216 virtio_tswap64s(vdev, &desc->addr);
217 virtio_tswap32s(vdev, &desc->len);
218 virtio_tswap16s(vdev, &desc->flags);
219 virtio_tswap16s(vdev, &desc->next);
220 }
221
222 static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq)
223 {
224 VRingMemoryRegionCaches *caches = atomic_rcu_read(&vq->vring.caches);
225 assert(caches != NULL);
226 return caches;
227 }
228 /* Called within rcu_read_lock(). */
229 static inline uint16_t vring_avail_flags(VirtQueue *vq)
230 {
231 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
232 hwaddr pa = offsetof(VRingAvail, flags);
233 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
234 }
235
236 /* Called within rcu_read_lock(). */
237 static inline uint16_t vring_avail_idx(VirtQueue *vq)
238 {
239 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
240 hwaddr pa = offsetof(VRingAvail, idx);
241 vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
242 return vq->shadow_avail_idx;
243 }
244
245 /* Called within rcu_read_lock(). */
246 static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
247 {
248 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
249 hwaddr pa = offsetof(VRingAvail, ring[i]);
250 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
251 }
252
253 /* Called within rcu_read_lock(). */
254 static inline uint16_t vring_get_used_event(VirtQueue *vq)
255 {
256 return vring_avail_ring(vq, vq->vring.num);
257 }
258
259 /* Called within rcu_read_lock(). */
260 static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem,
261 int i)
262 {
263 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
264 hwaddr pa = offsetof(VRingUsed, ring[i]);
265 virtio_tswap32s(vq->vdev, &uelem->id);
266 virtio_tswap32s(vq->vdev, &uelem->len);
267 address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem));
268 address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem));
269 }
270
271 /* Called within rcu_read_lock(). */
272 static uint16_t vring_used_idx(VirtQueue *vq)
273 {
274 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
275 hwaddr pa = offsetof(VRingUsed, idx);
276 return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
277 }
278
279 /* Called within rcu_read_lock(). */
280 static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val)
281 {
282 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
283 hwaddr pa = offsetof(VRingUsed, idx);
284 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
285 address_space_cache_invalidate(&caches->used, pa, sizeof(val));
286 vq->used_idx = val;
287 }
288
289 /* Called within rcu_read_lock(). */
290 static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask)
291 {
292 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
293 VirtIODevice *vdev = vq->vdev;
294 hwaddr pa = offsetof(VRingUsed, flags);
295 uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
296
297 virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask);
298 address_space_cache_invalidate(&caches->used, pa, sizeof(flags));
299 }
300
301 /* Called within rcu_read_lock(). */
302 static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask)
303 {
304 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
305 VirtIODevice *vdev = vq->vdev;
306 hwaddr pa = offsetof(VRingUsed, flags);
307 uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
308
309 virtio_stw_phys_cached(vdev, &caches->used, pa, flags & ~mask);
310 address_space_cache_invalidate(&caches->used, pa, sizeof(flags));
311 }
312
313 /* Called within rcu_read_lock(). */
314 static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val)
315 {
316 VRingMemoryRegionCaches *caches;
317 hwaddr pa;
318 if (!vq->notification) {
319 return;
320 }
321
322 caches = vring_get_region_caches(vq);
323 pa = offsetof(VRingUsed, ring[vq->vring.num]);
324 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
325 address_space_cache_invalidate(&caches->used, pa, sizeof(val));
326 }
327
328 void virtio_queue_set_notification(VirtQueue *vq, int enable)
329 {
330 vq->notification = enable;
331
332 if (!vq->vring.desc) {
333 return;
334 }
335
336 rcu_read_lock();
337 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) {
338 vring_set_avail_event(vq, vring_avail_idx(vq));
339 } else if (enable) {
340 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
341 } else {
342 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
343 }
344 if (enable) {
345 /* Expose avail event/used flags before caller checks the avail idx. */
346 smp_mb();
347 }
348 rcu_read_unlock();
349 }
350
351 int virtio_queue_ready(VirtQueue *vq)
352 {
353 return vq->vring.avail != 0;
354 }
355
356 /* Fetch avail_idx from VQ memory only when we really need to know if
357 * guest has added some buffers.
358 * Called within rcu_read_lock(). */
359 static int virtio_queue_empty_rcu(VirtQueue *vq)
360 {
361 if (unlikely(vq->vdev->broken)) {
362 return 1;
363 }
364
365 if (unlikely(!vq->vring.avail)) {
366 return 1;
367 }
368
369 if (vq->shadow_avail_idx != vq->last_avail_idx) {
370 return 0;
371 }
372
373 return vring_avail_idx(vq) == vq->last_avail_idx;
374 }
375
376 int virtio_queue_empty(VirtQueue *vq)
377 {
378 bool empty;
379
380 if (unlikely(vq->vdev->broken)) {
381 return 1;
382 }
383
384 if (unlikely(!vq->vring.avail)) {
385 return 1;
386 }
387
388 if (vq->shadow_avail_idx != vq->last_avail_idx) {
389 return 0;
390 }
391
392 rcu_read_lock();
393 empty = vring_avail_idx(vq) == vq->last_avail_idx;
394 rcu_read_unlock();
395 return empty;
396 }
397
398 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem,
399 unsigned int len)
400 {
401 AddressSpace *dma_as = vq->vdev->dma_as;
402 unsigned int offset;
403 int i;
404
405 offset = 0;
406 for (i = 0; i < elem->in_num; i++) {
407 size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
408
409 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base,
410 elem->in_sg[i].iov_len,
411 DMA_DIRECTION_FROM_DEVICE, size);
412
413 offset += size;
414 }
415
416 for (i = 0; i < elem->out_num; i++)
417 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base,
418 elem->out_sg[i].iov_len,
419 DMA_DIRECTION_TO_DEVICE,
420 elem->out_sg[i].iov_len);
421 }
422
423 /* virtqueue_detach_element:
424 * @vq: The #VirtQueue
425 * @elem: The #VirtQueueElement
426 * @len: number of bytes written
427 *
428 * Detach the element from the virtqueue. This function is suitable for device
429 * reset or other situations where a #VirtQueueElement is simply freed and will
430 * not be pushed or discarded.
431 */
432 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
433 unsigned int len)
434 {
435 vq->inuse--;
436 virtqueue_unmap_sg(vq, elem, len);
437 }
438
439 /* virtqueue_unpop:
440 * @vq: The #VirtQueue
441 * @elem: The #VirtQueueElement
442 * @len: number of bytes written
443 *
444 * Pretend the most recent element wasn't popped from the virtqueue. The next
445 * call to virtqueue_pop() will refetch the element.
446 */
447 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
448 unsigned int len)
449 {
450 vq->last_avail_idx--;
451 virtqueue_detach_element(vq, elem, len);
452 }
453
454 /* virtqueue_rewind:
455 * @vq: The #VirtQueue
456 * @num: Number of elements to push back
457 *
458 * Pretend that elements weren't popped from the virtqueue. The next
459 * virtqueue_pop() will refetch the oldest element.
460 *
461 * Use virtqueue_unpop() instead if you have a VirtQueueElement.
462 *
463 * Returns: true on success, false if @num is greater than the number of in use
464 * elements.
465 */
466 bool virtqueue_rewind(VirtQueue *vq, unsigned int num)
467 {
468 if (num > vq->inuse) {
469 return false;
470 }
471 vq->last_avail_idx -= num;
472 vq->inuse -= num;
473 return true;
474 }
475
476 /* Called within rcu_read_lock(). */
477 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
478 unsigned int len, unsigned int idx)
479 {
480 VRingUsedElem uelem;
481
482 trace_virtqueue_fill(vq, elem, len, idx);
483
484 virtqueue_unmap_sg(vq, elem, len);
485
486 if (unlikely(vq->vdev->broken)) {
487 return;
488 }
489
490 if (unlikely(!vq->vring.used)) {
491 return;
492 }
493
494 idx = (idx + vq->used_idx) % vq->vring.num;
495
496 uelem.id = elem->index;
497 uelem.len = len;
498 vring_used_write(vq, &uelem, idx);
499 }
500
501 /* Called within rcu_read_lock(). */
502 void virtqueue_flush(VirtQueue *vq, unsigned int count)
503 {
504 uint16_t old, new;
505
506 if (unlikely(vq->vdev->broken)) {
507 vq->inuse -= count;
508 return;
509 }
510
511 if (unlikely(!vq->vring.used)) {
512 return;
513 }
514
515 /* Make sure buffer is written before we update index. */
516 smp_wmb();
517 trace_virtqueue_flush(vq, count);
518 old = vq->used_idx;
519 new = old + count;
520 vring_used_idx_set(vq, new);
521 vq->inuse -= count;
522 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old)))
523 vq->signalled_used_valid = false;
524 }
525
526 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
527 unsigned int len)
528 {
529 rcu_read_lock();
530 virtqueue_fill(vq, elem, len, 0);
531 virtqueue_flush(vq, 1);
532 rcu_read_unlock();
533 }
534
535 /* Called within rcu_read_lock(). */
536 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx)
537 {
538 uint16_t num_heads = vring_avail_idx(vq) - idx;
539
540 /* Check it isn't doing very strange things with descriptor numbers. */
541 if (num_heads > vq->vring.num) {
542 virtio_error(vq->vdev, "Guest moved used index from %u to %u",
543 idx, vq->shadow_avail_idx);
544 return -EINVAL;
545 }
546 /* On success, callers read a descriptor at vq->last_avail_idx.
547 * Make sure descriptor read does not bypass avail index read. */
548 if (num_heads) {
549 smp_rmb();
550 }
551
552 return num_heads;
553 }
554
555 /* Called within rcu_read_lock(). */
556 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx,
557 unsigned int *head)
558 {
559 /* Grab the next descriptor number they're advertising, and increment
560 * the index we've seen. */
561 *head = vring_avail_ring(vq, idx % vq->vring.num);
562
563 /* If their number is silly, that's a fatal mistake. */
564 if (*head >= vq->vring.num) {
565 virtio_error(vq->vdev, "Guest says index %u is available", *head);
566 return false;
567 }
568
569 return true;
570 }
571
572 enum {
573 VIRTQUEUE_READ_DESC_ERROR = -1,
574 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */
575 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
576 };
577
578 static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc,
579 MemoryRegionCache *desc_cache, unsigned int max,
580 unsigned int *next)
581 {
582 /* If this descriptor says it doesn't chain, we're done. */
583 if (!(desc->flags & VRING_DESC_F_NEXT)) {
584 return VIRTQUEUE_READ_DESC_DONE;
585 }
586
587 /* Check they're not leading us off end of descriptors. */
588 *next = desc->next;
589 /* Make sure compiler knows to grab that: we don't want it changing! */
590 smp_wmb();
591
592 if (*next >= max) {
593 virtio_error(vdev, "Desc next is %u", *next);
594 return VIRTQUEUE_READ_DESC_ERROR;
595 }
596
597 vring_desc_read(vdev, desc, desc_cache, *next);
598 return VIRTQUEUE_READ_DESC_MORE;
599 }
600
601 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
602 unsigned int *out_bytes,
603 unsigned max_in_bytes, unsigned max_out_bytes)
604 {
605 VirtIODevice *vdev = vq->vdev;
606 unsigned int max, idx;
607 unsigned int total_bufs, in_total, out_total;
608 VRingMemoryRegionCaches *caches;
609 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID;
610 int64_t len = 0;
611 int rc;
612
613 if (unlikely(!vq->vring.desc)) {
614 if (in_bytes) {
615 *in_bytes = 0;
616 }
617 if (out_bytes) {
618 *out_bytes = 0;
619 }
620 return;
621 }
622
623 rcu_read_lock();
624 idx = vq->last_avail_idx;
625 total_bufs = in_total = out_total = 0;
626
627 max = vq->vring.num;
628 caches = vring_get_region_caches(vq);
629 if (caches->desc.len < max * sizeof(VRingDesc)) {
630 virtio_error(vdev, "Cannot map descriptor ring");
631 goto err;
632 }
633
634 while ((rc = virtqueue_num_heads(vq, idx)) > 0) {
635 MemoryRegionCache *desc_cache = &caches->desc;
636 unsigned int num_bufs;
637 VRingDesc desc;
638 unsigned int i;
639
640 num_bufs = total_bufs;
641
642 if (!virtqueue_get_head(vq, idx++, &i)) {
643 goto err;
644 }
645
646 vring_desc_read(vdev, &desc, desc_cache, i);
647
648 if (desc.flags & VRING_DESC_F_INDIRECT) {
649 if (!desc.len || (desc.len % sizeof(VRingDesc))) {
650 virtio_error(vdev, "Invalid size for indirect buffer table");
651 goto err;
652 }
653
654 /* If we've got too many, that implies a descriptor loop. */
655 if (num_bufs >= max) {
656 virtio_error(vdev, "Looped descriptor");
657 goto err;
658 }
659
660 /* loop over the indirect descriptor table */
661 len = address_space_cache_init(&indirect_desc_cache,
662 vdev->dma_as,
663 desc.addr, desc.len, false);
664 desc_cache = &indirect_desc_cache;
665 if (len < desc.len) {
666 virtio_error(vdev, "Cannot map indirect buffer");
667 goto err;
668 }
669
670 max = desc.len / sizeof(VRingDesc);
671 num_bufs = i = 0;
672 vring_desc_read(vdev, &desc, desc_cache, i);
673 }
674
675 do {
676 /* If we've got too many, that implies a descriptor loop. */
677 if (++num_bufs > max) {
678 virtio_error(vdev, "Looped descriptor");
679 goto err;
680 }
681
682 if (desc.flags & VRING_DESC_F_WRITE) {
683 in_total += desc.len;
684 } else {
685 out_total += desc.len;
686 }
687 if (in_total >= max_in_bytes && out_total >= max_out_bytes) {
688 goto done;
689 }
690
691 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i);
692 } while (rc == VIRTQUEUE_READ_DESC_MORE);
693
694 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
695 goto err;
696 }
697
698 if (desc_cache == &indirect_desc_cache) {
699 address_space_cache_destroy(&indirect_desc_cache);
700 total_bufs++;
701 } else {
702 total_bufs = num_bufs;
703 }
704 }
705
706 if (rc < 0) {
707 goto err;
708 }
709
710 done:
711 address_space_cache_destroy(&indirect_desc_cache);
712 if (in_bytes) {
713 *in_bytes = in_total;
714 }
715 if (out_bytes) {
716 *out_bytes = out_total;
717 }
718 rcu_read_unlock();
719 return;
720
721 err:
722 in_total = out_total = 0;
723 goto done;
724 }
725
726 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
727 unsigned int out_bytes)
728 {
729 unsigned int in_total, out_total;
730
731 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes);
732 return in_bytes <= in_total && out_bytes <= out_total;
733 }
734
735 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg,
736 hwaddr *addr, struct iovec *iov,
737 unsigned int max_num_sg, bool is_write,
738 hwaddr pa, size_t sz)
739 {
740 bool ok = false;
741 unsigned num_sg = *p_num_sg;
742 assert(num_sg <= max_num_sg);
743
744 if (!sz) {
745 virtio_error(vdev, "virtio: zero sized buffers are not allowed");
746 goto out;
747 }
748
749 while (sz) {
750 hwaddr len = sz;
751
752 if (num_sg == max_num_sg) {
753 virtio_error(vdev, "virtio: too many write descriptors in "
754 "indirect table");
755 goto out;
756 }
757
758 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len,
759 is_write ?
760 DMA_DIRECTION_FROM_DEVICE :
761 DMA_DIRECTION_TO_DEVICE);
762 if (!iov[num_sg].iov_base) {
763 virtio_error(vdev, "virtio: bogus descriptor or out of resources");
764 goto out;
765 }
766
767 iov[num_sg].iov_len = len;
768 addr[num_sg] = pa;
769
770 sz -= len;
771 pa += len;
772 num_sg++;
773 }
774 ok = true;
775
776 out:
777 *p_num_sg = num_sg;
778 return ok;
779 }
780
781 /* Only used by error code paths before we have a VirtQueueElement (therefore
782 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to
783 * yet.
784 */
785 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num,
786 struct iovec *iov)
787 {
788 unsigned int i;
789
790 for (i = 0; i < out_num + in_num; i++) {
791 int is_write = i >= out_num;
792
793 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0);
794 iov++;
795 }
796 }
797
798 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg,
799 hwaddr *addr, unsigned int num_sg,
800 int is_write)
801 {
802 unsigned int i;
803 hwaddr len;
804
805 for (i = 0; i < num_sg; i++) {
806 len = sg[i].iov_len;
807 sg[i].iov_base = dma_memory_map(vdev->dma_as,
808 addr[i], &len, is_write ?
809 DMA_DIRECTION_FROM_DEVICE :
810 DMA_DIRECTION_TO_DEVICE);
811 if (!sg[i].iov_base) {
812 error_report("virtio: error trying to map MMIO memory");
813 exit(1);
814 }
815 if (len != sg[i].iov_len) {
816 error_report("virtio: unexpected memory split");
817 exit(1);
818 }
819 }
820 }
821
822 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem)
823 {
824 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, 1);
825 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 0);
826 }
827
828 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num)
829 {
830 VirtQueueElement *elem;
831 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0]));
832 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]);
833 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]);
834 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0]));
835 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]);
836 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]);
837
838 assert(sz >= sizeof(VirtQueueElement));
839 elem = g_malloc(out_sg_end);
840 trace_virtqueue_alloc_element(elem, sz, in_num, out_num);
841 elem->out_num = out_num;
842 elem->in_num = in_num;
843 elem->in_addr = (void *)elem + in_addr_ofs;
844 elem->out_addr = (void *)elem + out_addr_ofs;
845 elem->in_sg = (void *)elem + in_sg_ofs;
846 elem->out_sg = (void *)elem + out_sg_ofs;
847 return elem;
848 }
849
850 void *virtqueue_pop(VirtQueue *vq, size_t sz)
851 {
852 unsigned int i, head, max;
853 VRingMemoryRegionCaches *caches;
854 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID;
855 MemoryRegionCache *desc_cache;
856 int64_t len;
857 VirtIODevice *vdev = vq->vdev;
858 VirtQueueElement *elem = NULL;
859 unsigned out_num, in_num, elem_entries;
860 hwaddr addr[VIRTQUEUE_MAX_SIZE];
861 struct iovec iov[VIRTQUEUE_MAX_SIZE];
862 VRingDesc desc;
863 int rc;
864
865 if (unlikely(vdev->broken)) {
866 return NULL;
867 }
868 rcu_read_lock();
869 if (virtio_queue_empty_rcu(vq)) {
870 goto done;
871 }
872 /* Needed after virtio_queue_empty(), see comment in
873 * virtqueue_num_heads(). */
874 smp_rmb();
875
876 /* When we start there are none of either input nor output. */
877 out_num = in_num = elem_entries = 0;
878
879 max = vq->vring.num;
880
881 if (vq->inuse >= vq->vring.num) {
882 virtio_error(vdev, "Virtqueue size exceeded");
883 goto done;
884 }
885
886 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) {
887 goto done;
888 }
889
890 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
891 vring_set_avail_event(vq, vq->last_avail_idx);
892 }
893
894 i = head;
895
896 caches = vring_get_region_caches(vq);
897 if (caches->desc.len < max * sizeof(VRingDesc)) {
898 virtio_error(vdev, "Cannot map descriptor ring");
899 goto done;
900 }
901
902 desc_cache = &caches->desc;
903 vring_desc_read(vdev, &desc, desc_cache, i);
904 if (desc.flags & VRING_DESC_F_INDIRECT) {
905 if (!desc.len || (desc.len % sizeof(VRingDesc))) {
906 virtio_error(vdev, "Invalid size for indirect buffer table");
907 goto done;
908 }
909
910 /* loop over the indirect descriptor table */
911 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as,
912 desc.addr, desc.len, false);
913 desc_cache = &indirect_desc_cache;
914 if (len < desc.len) {
915 virtio_error(vdev, "Cannot map indirect buffer");
916 goto done;
917 }
918
919 max = desc.len / sizeof(VRingDesc);
920 i = 0;
921 vring_desc_read(vdev, &desc, desc_cache, i);
922 }
923
924 /* Collect all the descriptors */
925 do {
926 bool map_ok;
927
928 if (desc.flags & VRING_DESC_F_WRITE) {
929 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num,
930 iov + out_num,
931 VIRTQUEUE_MAX_SIZE - out_num, true,
932 desc.addr, desc.len);
933 } else {
934 if (in_num) {
935 virtio_error(vdev, "Incorrect order for descriptors");
936 goto err_undo_map;
937 }
938 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov,
939 VIRTQUEUE_MAX_SIZE, false,
940 desc.addr, desc.len);
941 }
942 if (!map_ok) {
943 goto err_undo_map;
944 }
945
946 /* If we've got too many, that implies a descriptor loop. */
947 if (++elem_entries > max) {
948 virtio_error(vdev, "Looped descriptor");
949 goto err_undo_map;
950 }
951
952 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i);
953 } while (rc == VIRTQUEUE_READ_DESC_MORE);
954
955 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
956 goto err_undo_map;
957 }
958
959 /* Now copy what we have collected and mapped */
960 elem = virtqueue_alloc_element(sz, out_num, in_num);
961 elem->index = head;
962 for (i = 0; i < out_num; i++) {
963 elem->out_addr[i] = addr[i];
964 elem->out_sg[i] = iov[i];
965 }
966 for (i = 0; i < in_num; i++) {
967 elem->in_addr[i] = addr[out_num + i];
968 elem->in_sg[i] = iov[out_num + i];
969 }
970
971 vq->inuse++;
972
973 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
974 done:
975 address_space_cache_destroy(&indirect_desc_cache);
976 rcu_read_unlock();
977
978 return elem;
979
980 err_undo_map:
981 virtqueue_undo_map_desc(out_num, in_num, iov);
982 goto done;
983 }
984
985 /* virtqueue_drop_all:
986 * @vq: The #VirtQueue
987 * Drops all queued buffers and indicates them to the guest
988 * as if they are done. Useful when buffers can not be
989 * processed but must be returned to the guest.
990 */
991 unsigned int virtqueue_drop_all(VirtQueue *vq)
992 {
993 unsigned int dropped = 0;
994 VirtQueueElement elem = {};
995 VirtIODevice *vdev = vq->vdev;
996 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
997
998 if (unlikely(vdev->broken)) {
999 return 0;
1000 }
1001
1002 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) {
1003 /* works similar to virtqueue_pop but does not map buffers
1004 * and does not allocate any memory */
1005 smp_rmb();
1006 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) {
1007 break;
1008 }
1009 vq->inuse++;
1010 vq->last_avail_idx++;
1011 if (fEventIdx) {
1012 vring_set_avail_event(vq, vq->last_avail_idx);
1013 }
1014 /* immediately push the element, nothing to unmap
1015 * as both in_num and out_num are set to 0 */
1016 virtqueue_push(vq, &elem, 0);
1017 dropped++;
1018 }
1019
1020 return dropped;
1021 }
1022
1023 /* Reading and writing a structure directly to QEMUFile is *awful*, but
1024 * it is what QEMU has always done by mistake. We can change it sooner
1025 * or later by bumping the version number of the affected vm states.
1026 * In the meanwhile, since the in-memory layout of VirtQueueElement
1027 * has changed, we need to marshal to and from the layout that was
1028 * used before the change.
1029 */
1030 typedef struct VirtQueueElementOld {
1031 unsigned int index;
1032 unsigned int out_num;
1033 unsigned int in_num;
1034 hwaddr in_addr[VIRTQUEUE_MAX_SIZE];
1035 hwaddr out_addr[VIRTQUEUE_MAX_SIZE];
1036 struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
1037 struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
1038 } VirtQueueElementOld;
1039
1040 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz)
1041 {
1042 VirtQueueElement *elem;
1043 VirtQueueElementOld data;
1044 int i;
1045
1046 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld));
1047
1048 /* TODO: teach all callers that this can fail, and return failure instead
1049 * of asserting here.
1050 * This is just one thing (there are probably more) that must be
1051 * fixed before we can allow NDEBUG compilation.
1052 */
1053 assert(ARRAY_SIZE(data.in_addr) >= data.in_num);
1054 assert(ARRAY_SIZE(data.out_addr) >= data.out_num);
1055
1056 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num);
1057 elem->index = data.index;
1058
1059 for (i = 0; i < elem->in_num; i++) {
1060 elem->in_addr[i] = data.in_addr[i];
1061 }
1062
1063 for (i = 0; i < elem->out_num; i++) {
1064 elem->out_addr[i] = data.out_addr[i];
1065 }
1066
1067 for (i = 0; i < elem->in_num; i++) {
1068 /* Base is overwritten by virtqueue_map. */
1069 elem->in_sg[i].iov_base = 0;
1070 elem->in_sg[i].iov_len = data.in_sg[i].iov_len;
1071 }
1072
1073 for (i = 0; i < elem->out_num; i++) {
1074 /* Base is overwritten by virtqueue_map. */
1075 elem->out_sg[i].iov_base = 0;
1076 elem->out_sg[i].iov_len = data.out_sg[i].iov_len;
1077 }
1078
1079 virtqueue_map(vdev, elem);
1080 return elem;
1081 }
1082
1083 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem)
1084 {
1085 VirtQueueElementOld data;
1086 int i;
1087
1088 memset(&data, 0, sizeof(data));
1089 data.index = elem->index;
1090 data.in_num = elem->in_num;
1091 data.out_num = elem->out_num;
1092
1093 for (i = 0; i < elem->in_num; i++) {
1094 data.in_addr[i] = elem->in_addr[i];
1095 }
1096
1097 for (i = 0; i < elem->out_num; i++) {
1098 data.out_addr[i] = elem->out_addr[i];
1099 }
1100
1101 for (i = 0; i < elem->in_num; i++) {
1102 /* Base is overwritten by virtqueue_map when loading. Do not
1103 * save it, as it would leak the QEMU address space layout. */
1104 data.in_sg[i].iov_len = elem->in_sg[i].iov_len;
1105 }
1106
1107 for (i = 0; i < elem->out_num; i++) {
1108 /* Do not save iov_base as above. */
1109 data.out_sg[i].iov_len = elem->out_sg[i].iov_len;
1110 }
1111 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld));
1112 }
1113
1114 /* virtio device */
1115 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector)
1116 {
1117 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
1118 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1119
1120 if (unlikely(vdev->broken)) {
1121 return;
1122 }
1123
1124 if (k->notify) {
1125 k->notify(qbus->parent, vector);
1126 }
1127 }
1128
1129 void virtio_update_irq(VirtIODevice *vdev)
1130 {
1131 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR);
1132 }
1133
1134 static int virtio_validate_features(VirtIODevice *vdev)
1135 {
1136 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1137
1138 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) &&
1139 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {
1140 return -EFAULT;
1141 }
1142
1143 if (k->validate_features) {
1144 return k->validate_features(vdev);
1145 } else {
1146 return 0;
1147 }
1148 }
1149
1150 int virtio_set_status(VirtIODevice *vdev, uint8_t val)
1151 {
1152 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1153 trace_virtio_set_status(vdev, val);
1154
1155 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1156 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) &&
1157 val & VIRTIO_CONFIG_S_FEATURES_OK) {
1158 int ret = virtio_validate_features(vdev);
1159
1160 if (ret) {
1161 return ret;
1162 }
1163 }
1164 }
1165 vdev->started = val & VIRTIO_CONFIG_S_DRIVER_OK;
1166 if (unlikely(vdev->start_on_kick && vdev->started)) {
1167 vdev->start_on_kick = false;
1168 }
1169
1170 if (k->set_status) {
1171 k->set_status(vdev, val);
1172 }
1173 vdev->status = val;
1174
1175 return 0;
1176 }
1177
1178 static enum virtio_device_endian virtio_default_endian(void)
1179 {
1180 if (target_words_bigendian()) {
1181 return VIRTIO_DEVICE_ENDIAN_BIG;
1182 } else {
1183 return VIRTIO_DEVICE_ENDIAN_LITTLE;
1184 }
1185 }
1186
1187 static enum virtio_device_endian virtio_current_cpu_endian(void)
1188 {
1189 CPUClass *cc = CPU_GET_CLASS(current_cpu);
1190
1191 if (cc->virtio_is_big_endian(current_cpu)) {
1192 return VIRTIO_DEVICE_ENDIAN_BIG;
1193 } else {
1194 return VIRTIO_DEVICE_ENDIAN_LITTLE;
1195 }
1196 }
1197
1198 void virtio_reset(void *opaque)
1199 {
1200 VirtIODevice *vdev = opaque;
1201 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1202 int i;
1203
1204 virtio_set_status(vdev, 0);
1205 if (current_cpu) {
1206 /* Guest initiated reset */
1207 vdev->device_endian = virtio_current_cpu_endian();
1208 } else {
1209 /* System reset */
1210 vdev->device_endian = virtio_default_endian();
1211 }
1212
1213 if (k->reset) {
1214 k->reset(vdev);
1215 }
1216
1217 vdev->start_on_kick = (virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
1218 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1));
1219 vdev->started = false;
1220 vdev->broken = false;
1221 vdev->guest_features = 0;
1222 vdev->queue_sel = 0;
1223 vdev->status = 0;
1224 atomic_set(&vdev->isr, 0);
1225 vdev->config_vector = VIRTIO_NO_VECTOR;
1226 virtio_notify_vector(vdev, vdev->config_vector);
1227
1228 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1229 vdev->vq[i].vring.desc = 0;
1230 vdev->vq[i].vring.avail = 0;
1231 vdev->vq[i].vring.used = 0;
1232 vdev->vq[i].last_avail_idx = 0;
1233 vdev->vq[i].shadow_avail_idx = 0;
1234 vdev->vq[i].used_idx = 0;
1235 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR);
1236 vdev->vq[i].signalled_used = 0;
1237 vdev->vq[i].signalled_used_valid = false;
1238 vdev->vq[i].notification = true;
1239 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default;
1240 vdev->vq[i].inuse = 0;
1241 virtio_virtqueue_reset_region_cache(&vdev->vq[i]);
1242 }
1243 }
1244
1245 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr)
1246 {
1247 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1248 uint8_t val;
1249
1250 if (addr + sizeof(val) > vdev->config_len) {
1251 return (uint32_t)-1;
1252 }
1253
1254 k->get_config(vdev, vdev->config);
1255
1256 val = ldub_p(vdev->config + addr);
1257 return val;
1258 }
1259
1260 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr)
1261 {
1262 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1263 uint16_t val;
1264
1265 if (addr + sizeof(val) > vdev->config_len) {
1266 return (uint32_t)-1;
1267 }
1268
1269 k->get_config(vdev, vdev->config);
1270
1271 val = lduw_p(vdev->config + addr);
1272 return val;
1273 }
1274
1275 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr)
1276 {
1277 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1278 uint32_t val;
1279
1280 if (addr + sizeof(val) > vdev->config_len) {
1281 return (uint32_t)-1;
1282 }
1283
1284 k->get_config(vdev, vdev->config);
1285
1286 val = ldl_p(vdev->config + addr);
1287 return val;
1288 }
1289
1290 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data)
1291 {
1292 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1293 uint8_t val = data;
1294
1295 if (addr + sizeof(val) > vdev->config_len) {
1296 return;
1297 }
1298
1299 stb_p(vdev->config + addr, val);
1300
1301 if (k->set_config) {
1302 k->set_config(vdev, vdev->config);
1303 }
1304 }
1305
1306 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data)
1307 {
1308 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1309 uint16_t val = data;
1310
1311 if (addr + sizeof(val) > vdev->config_len) {
1312 return;
1313 }
1314
1315 stw_p(vdev->config + addr, val);
1316
1317 if (k->set_config) {
1318 k->set_config(vdev, vdev->config);
1319 }
1320 }
1321
1322 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data)
1323 {
1324 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1325 uint32_t val = data;
1326
1327 if (addr + sizeof(val) > vdev->config_len) {
1328 return;
1329 }
1330
1331 stl_p(vdev->config + addr, val);
1332
1333 if (k->set_config) {
1334 k->set_config(vdev, vdev->config);
1335 }
1336 }
1337
1338 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr)
1339 {
1340 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1341 uint8_t val;
1342
1343 if (addr + sizeof(val) > vdev->config_len) {
1344 return (uint32_t)-1;
1345 }
1346
1347 k->get_config(vdev, vdev->config);
1348
1349 val = ldub_p(vdev->config + addr);
1350 return val;
1351 }
1352
1353 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr)
1354 {
1355 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1356 uint16_t val;
1357
1358 if (addr + sizeof(val) > vdev->config_len) {
1359 return (uint32_t)-1;
1360 }
1361
1362 k->get_config(vdev, vdev->config);
1363
1364 val = lduw_le_p(vdev->config + addr);
1365 return val;
1366 }
1367
1368 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr)
1369 {
1370 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1371 uint32_t val;
1372
1373 if (addr + sizeof(val) > vdev->config_len) {
1374 return (uint32_t)-1;
1375 }
1376
1377 k->get_config(vdev, vdev->config);
1378
1379 val = ldl_le_p(vdev->config + addr);
1380 return val;
1381 }
1382
1383 void virtio_config_modern_writeb(VirtIODevice *vdev,
1384 uint32_t addr, uint32_t data)
1385 {
1386 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1387 uint8_t val = data;
1388
1389 if (addr + sizeof(val) > vdev->config_len) {
1390 return;
1391 }
1392
1393 stb_p(vdev->config + addr, val);
1394
1395 if (k->set_config) {
1396 k->set_config(vdev, vdev->config);
1397 }
1398 }
1399
1400 void virtio_config_modern_writew(VirtIODevice *vdev,
1401 uint32_t addr, uint32_t data)
1402 {
1403 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1404 uint16_t val = data;
1405
1406 if (addr + sizeof(val) > vdev->config_len) {
1407 return;
1408 }
1409
1410 stw_le_p(vdev->config + addr, val);
1411
1412 if (k->set_config) {
1413 k->set_config(vdev, vdev->config);
1414 }
1415 }
1416
1417 void virtio_config_modern_writel(VirtIODevice *vdev,
1418 uint32_t addr, uint32_t data)
1419 {
1420 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1421 uint32_t val = data;
1422
1423 if (addr + sizeof(val) > vdev->config_len) {
1424 return;
1425 }
1426
1427 stl_le_p(vdev->config + addr, val);
1428
1429 if (k->set_config) {
1430 k->set_config(vdev, vdev->config);
1431 }
1432 }
1433
1434 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)
1435 {
1436 if (!vdev->vq[n].vring.num) {
1437 return;
1438 }
1439 vdev->vq[n].vring.desc = addr;
1440 virtio_queue_update_rings(vdev, n);
1441 }
1442
1443 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n)
1444 {
1445 return vdev->vq[n].vring.desc;
1446 }
1447
1448 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
1449 hwaddr avail, hwaddr used)
1450 {
1451 if (!vdev->vq[n].vring.num) {
1452 return;
1453 }
1454 vdev->vq[n].vring.desc = desc;
1455 vdev->vq[n].vring.avail = avail;
1456 vdev->vq[n].vring.used = used;
1457 virtio_init_region_cache(vdev, n);
1458 }
1459
1460 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
1461 {
1462 /* Don't allow guest to flip queue between existent and
1463 * nonexistent states, or to set it to an invalid size.
1464 */
1465 if (!!num != !!vdev->vq[n].vring.num ||
1466 num > VIRTQUEUE_MAX_SIZE ||
1467 num < 0) {
1468 return;
1469 }
1470 vdev->vq[n].vring.num = num;
1471 }
1472
1473 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector)
1474 {
1475 return QLIST_FIRST(&vdev->vector_queues[vector]);
1476 }
1477
1478 VirtQueue *virtio_vector_next_queue(VirtQueue *vq)
1479 {
1480 return QLIST_NEXT(vq, node);
1481 }
1482
1483 int virtio_queue_get_num(VirtIODevice *vdev, int n)
1484 {
1485 return vdev->vq[n].vring.num;
1486 }
1487
1488 int virtio_queue_get_max_num(VirtIODevice *vdev, int n)
1489 {
1490 return vdev->vq[n].vring.num_default;
1491 }
1492
1493 int virtio_get_num_queues(VirtIODevice *vdev)
1494 {
1495 int i;
1496
1497 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1498 if (!virtio_queue_get_num(vdev, i)) {
1499 break;
1500 }
1501 }
1502
1503 return i;
1504 }
1505
1506 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align)
1507 {
1508 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
1509 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1510
1511 /* virtio-1 compliant devices cannot change the alignment */
1512 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1513 error_report("tried to modify queue alignment for virtio-1 device");
1514 return;
1515 }
1516 /* Check that the transport told us it was going to do this
1517 * (so a buggy transport will immediately assert rather than
1518 * silently failing to migrate this state)
1519 */
1520 assert(k->has_variable_vring_alignment);
1521
1522 if (align) {
1523 vdev->vq[n].vring.align = align;
1524 virtio_queue_update_rings(vdev, n);
1525 }
1526 }
1527
1528 static bool virtio_queue_notify_aio_vq(VirtQueue *vq)
1529 {
1530 bool ret = false;
1531
1532 if (vq->vring.desc && vq->handle_aio_output) {
1533 VirtIODevice *vdev = vq->vdev;
1534
1535 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq);
1536 ret = vq->handle_aio_output(vdev, vq);
1537
1538 if (unlikely(vdev->start_on_kick)) {
1539 vdev->started = true;
1540 vdev->start_on_kick = false;
1541 }
1542 }
1543
1544 return ret;
1545 }
1546
1547 static void virtio_queue_notify_vq(VirtQueue *vq)
1548 {
1549 if (vq->vring.desc && vq->handle_output) {
1550 VirtIODevice *vdev = vq->vdev;
1551
1552 if (unlikely(vdev->broken)) {
1553 return;
1554 }
1555
1556 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq);
1557 vq->handle_output(vdev, vq);
1558
1559 if (unlikely(vdev->start_on_kick)) {
1560 vdev->started = true;
1561 vdev->start_on_kick = false;
1562 }
1563 }
1564 }
1565
1566 void virtio_queue_notify(VirtIODevice *vdev, int n)
1567 {
1568 VirtQueue *vq = &vdev->vq[n];
1569
1570 if (unlikely(!vq->vring.desc || vdev->broken)) {
1571 return;
1572 }
1573
1574 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq);
1575 if (vq->handle_aio_output) {
1576 event_notifier_set(&vq->host_notifier);
1577 } else if (vq->handle_output) {
1578 vq->handle_output(vdev, vq);
1579 }
1580
1581 if (unlikely(vdev->start_on_kick)) {
1582 vdev->started = true;
1583 vdev->start_on_kick = false;
1584 }
1585 }
1586
1587 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n)
1588 {
1589 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector :
1590 VIRTIO_NO_VECTOR;
1591 }
1592
1593 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector)
1594 {
1595 VirtQueue *vq = &vdev->vq[n];
1596
1597 if (n < VIRTIO_QUEUE_MAX) {
1598 if (vdev->vector_queues &&
1599 vdev->vq[n].vector != VIRTIO_NO_VECTOR) {
1600 QLIST_REMOVE(vq, node);
1601 }
1602 vdev->vq[n].vector = vector;
1603 if (vdev->vector_queues &&
1604 vector != VIRTIO_NO_VECTOR) {
1605 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node);
1606 }
1607 }
1608 }
1609
1610 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
1611 VirtIOHandleOutput handle_output)
1612 {
1613 int i;
1614
1615 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1616 if (vdev->vq[i].vring.num == 0)
1617 break;
1618 }
1619
1620 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE)
1621 abort();
1622
1623 vdev->vq[i].vring.num = queue_size;
1624 vdev->vq[i].vring.num_default = queue_size;
1625 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN;
1626 vdev->vq[i].handle_output = handle_output;
1627 vdev->vq[i].handle_aio_output = NULL;
1628
1629 return &vdev->vq[i];
1630 }
1631
1632 void virtio_del_queue(VirtIODevice *vdev, int n)
1633 {
1634 if (n < 0 || n >= VIRTIO_QUEUE_MAX) {
1635 abort();
1636 }
1637
1638 vdev->vq[n].vring.num = 0;
1639 vdev->vq[n].vring.num_default = 0;
1640 vdev->vq[n].handle_output = NULL;
1641 vdev->vq[n].handle_aio_output = NULL;
1642 }
1643
1644 static void virtio_set_isr(VirtIODevice *vdev, int value)
1645 {
1646 uint8_t old = atomic_read(&vdev->isr);
1647
1648 /* Do not write ISR if it does not change, so that its cacheline remains
1649 * shared in the common case where the guest does not read it.
1650 */
1651 if ((old & value) != value) {
1652 atomic_or(&vdev->isr, value);
1653 }
1654 }
1655
1656 /* Called within rcu_read_lock(). */
1657 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq)
1658 {
1659 uint16_t old, new;
1660 bool v;
1661 /* We need to expose used array entries before checking used event. */
1662 smp_mb();
1663 /* Always notify when queue is empty (when feature acknowledge) */
1664 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
1665 !vq->inuse && virtio_queue_empty(vq)) {
1666 return true;
1667 }
1668
1669 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
1670 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
1671 }
1672
1673 v = vq->signalled_used_valid;
1674 vq->signalled_used_valid = true;
1675 old = vq->signalled_used;
1676 new = vq->signalled_used = vq->used_idx;
1677 return !v || vring_need_event(vring_get_used_event(vq), new, old);
1678 }
1679
1680 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq)
1681 {
1682 bool should_notify;
1683 rcu_read_lock();
1684 should_notify = virtio_should_notify(vdev, vq);
1685 rcu_read_unlock();
1686
1687 if (!should_notify) {
1688 return;
1689 }
1690
1691 trace_virtio_notify_irqfd(vdev, vq);
1692
1693 /*
1694 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but
1695 * windows drivers included in virtio-win 1.8.0 (circa 2015) are
1696 * incorrectly polling this bit during crashdump and hibernation
1697 * in MSI mode, causing a hang if this bit is never updated.
1698 * Recent releases of Windows do not really shut down, but rather
1699 * log out and hibernate to make the next startup faster. Hence,
1700 * this manifested as a more serious hang during shutdown with
1701 *
1702 * Next driver release from 2016 fixed this problem, so working around it
1703 * is not a must, but it's easy to do so let's do it here.
1704 *
1705 * Note: it's safe to update ISR from any thread as it was switched
1706 * to an atomic operation.
1707 */
1708 virtio_set_isr(vq->vdev, 0x1);
1709 event_notifier_set(&vq->guest_notifier);
1710 }
1711
1712 static void virtio_irq(VirtQueue *vq)
1713 {
1714 virtio_set_isr(vq->vdev, 0x1);
1715 virtio_notify_vector(vq->vdev, vq->vector);
1716 }
1717
1718 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
1719 {
1720 bool should_notify;
1721 rcu_read_lock();
1722 should_notify = virtio_should_notify(vdev, vq);
1723 rcu_read_unlock();
1724
1725 if (!should_notify) {
1726 return;
1727 }
1728
1729 trace_virtio_notify(vdev, vq);
1730 virtio_irq(vq);
1731 }
1732
1733 void virtio_notify_config(VirtIODevice *vdev)
1734 {
1735 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
1736 return;
1737
1738 virtio_set_isr(vdev, 0x3);
1739 vdev->generation++;
1740 virtio_notify_vector(vdev, vdev->config_vector);
1741 }
1742
1743 static bool virtio_device_endian_needed(void *opaque)
1744 {
1745 VirtIODevice *vdev = opaque;
1746
1747 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
1748 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1749 return vdev->device_endian != virtio_default_endian();
1750 }
1751 /* Devices conforming to VIRTIO 1.0 or later are always LE. */
1752 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE;
1753 }
1754
1755 static bool virtio_64bit_features_needed(void *opaque)
1756 {
1757 VirtIODevice *vdev = opaque;
1758
1759 return (vdev->host_features >> 32) != 0;
1760 }
1761
1762 static bool virtio_virtqueue_needed(void *opaque)
1763 {
1764 VirtIODevice *vdev = opaque;
1765
1766 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1);
1767 }
1768
1769 static bool virtio_ringsize_needed(void *opaque)
1770 {
1771 VirtIODevice *vdev = opaque;
1772 int i;
1773
1774 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1775 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) {
1776 return true;
1777 }
1778 }
1779 return false;
1780 }
1781
1782 static bool virtio_extra_state_needed(void *opaque)
1783 {
1784 VirtIODevice *vdev = opaque;
1785 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
1786 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1787
1788 return k->has_extra_state &&
1789 k->has_extra_state(qbus->parent);
1790 }
1791
1792 static bool virtio_broken_needed(void *opaque)
1793 {
1794 VirtIODevice *vdev = opaque;
1795
1796 return vdev->broken;
1797 }
1798
1799 static bool virtio_started_needed(void *opaque)
1800 {
1801 VirtIODevice *vdev = opaque;
1802
1803 return vdev->started;
1804 }
1805
1806 static const VMStateDescription vmstate_virtqueue = {
1807 .name = "virtqueue_state",
1808 .version_id = 1,
1809 .minimum_version_id = 1,
1810 .fields = (VMStateField[]) {
1811 VMSTATE_UINT64(vring.avail, struct VirtQueue),
1812 VMSTATE_UINT64(vring.used, struct VirtQueue),
1813 VMSTATE_END_OF_LIST()
1814 }
1815 };
1816
1817 static const VMStateDescription vmstate_virtio_virtqueues = {
1818 .name = "virtio/virtqueues",
1819 .version_id = 1,
1820 .minimum_version_id = 1,
1821 .needed = &virtio_virtqueue_needed,
1822 .fields = (VMStateField[]) {
1823 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice,
1824 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue),
1825 VMSTATE_END_OF_LIST()
1826 }
1827 };
1828
1829 static const VMStateDescription vmstate_ringsize = {
1830 .name = "ringsize_state",
1831 .version_id = 1,
1832 .minimum_version_id = 1,
1833 .fields = (VMStateField[]) {
1834 VMSTATE_UINT32(vring.num_default, struct VirtQueue),
1835 VMSTATE_END_OF_LIST()
1836 }
1837 };
1838
1839 static const VMStateDescription vmstate_virtio_ringsize = {
1840 .name = "virtio/ringsize",
1841 .version_id = 1,
1842 .minimum_version_id = 1,
1843 .needed = &virtio_ringsize_needed,
1844 .fields = (VMStateField[]) {
1845 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice,
1846 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue),
1847 VMSTATE_END_OF_LIST()
1848 }
1849 };
1850
1851 static int get_extra_state(QEMUFile *f, void *pv, size_t size,
1852 const VMStateField *field)
1853 {
1854 VirtIODevice *vdev = pv;
1855 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
1856 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1857
1858 if (!k->load_extra_state) {
1859 return -1;
1860 } else {
1861 return k->load_extra_state(qbus->parent, f);
1862 }
1863 }
1864
1865 static int put_extra_state(QEMUFile *f, void *pv, size_t size,
1866 const VMStateField *field, QJSON *vmdesc)
1867 {
1868 VirtIODevice *vdev = pv;
1869 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
1870 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1871
1872 k->save_extra_state(qbus->parent, f);
1873 return 0;
1874 }
1875
1876 static const VMStateInfo vmstate_info_extra_state = {
1877 .name = "virtqueue_extra_state",
1878 .get = get_extra_state,
1879 .put = put_extra_state,
1880 };
1881
1882 static const VMStateDescription vmstate_virtio_extra_state = {
1883 .name = "virtio/extra_state",
1884 .version_id = 1,
1885 .minimum_version_id = 1,
1886 .needed = &virtio_extra_state_needed,
1887 .fields = (VMStateField[]) {
1888 {
1889 .name = "extra_state",
1890 .version_id = 0,
1891 .field_exists = NULL,
1892 .size = 0,
1893 .info = &vmstate_info_extra_state,
1894 .flags = VMS_SINGLE,
1895 .offset = 0,
1896 },
1897 VMSTATE_END_OF_LIST()
1898 }
1899 };
1900
1901 static const VMStateDescription vmstate_virtio_device_endian = {
1902 .name = "virtio/device_endian",
1903 .version_id = 1,
1904 .minimum_version_id = 1,
1905 .needed = &virtio_device_endian_needed,
1906 .fields = (VMStateField[]) {
1907 VMSTATE_UINT8(device_endian, VirtIODevice),
1908 VMSTATE_END_OF_LIST()
1909 }
1910 };
1911
1912 static const VMStateDescription vmstate_virtio_64bit_features = {
1913 .name = "virtio/64bit_features",
1914 .version_id = 1,
1915 .minimum_version_id = 1,
1916 .needed = &virtio_64bit_features_needed,
1917 .fields = (VMStateField[]) {
1918 VMSTATE_UINT64(guest_features, VirtIODevice),
1919 VMSTATE_END_OF_LIST()
1920 }
1921 };
1922
1923 static const VMStateDescription vmstate_virtio_broken = {
1924 .name = "virtio/broken",
1925 .version_id = 1,
1926 .minimum_version_id = 1,
1927 .needed = &virtio_broken_needed,
1928 .fields = (VMStateField[]) {
1929 VMSTATE_BOOL(broken, VirtIODevice),
1930 VMSTATE_END_OF_LIST()
1931 }
1932 };
1933
1934 static const VMStateDescription vmstate_virtio_started = {
1935 .name = "virtio/started",
1936 .version_id = 1,
1937 .minimum_version_id = 1,
1938 .needed = &virtio_started_needed,
1939 .fields = (VMStateField[]) {
1940 VMSTATE_BOOL(started, VirtIODevice),
1941 VMSTATE_END_OF_LIST()
1942 }
1943 };
1944
1945 static const VMStateDescription vmstate_virtio = {
1946 .name = "virtio",
1947 .version_id = 1,
1948 .minimum_version_id = 1,
1949 .minimum_version_id_old = 1,
1950 .fields = (VMStateField[]) {
1951 VMSTATE_END_OF_LIST()
1952 },
1953 .subsections = (const VMStateDescription*[]) {
1954 &vmstate_virtio_device_endian,
1955 &vmstate_virtio_64bit_features,
1956 &vmstate_virtio_virtqueues,
1957 &vmstate_virtio_ringsize,
1958 &vmstate_virtio_broken,
1959 &vmstate_virtio_extra_state,
1960 &vmstate_virtio_started,
1961 NULL
1962 }
1963 };
1964
1965 int virtio_save(VirtIODevice *vdev, QEMUFile *f)
1966 {
1967 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
1968 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1969 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
1970 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff);
1971 int i;
1972
1973 if (k->save_config) {
1974 k->save_config(qbus->parent, f);
1975 }
1976
1977 qemu_put_8s(f, &vdev->status);
1978 qemu_put_8s(f, &vdev->isr);
1979 qemu_put_be16s(f, &vdev->queue_sel);
1980 qemu_put_be32s(f, &guest_features_lo);
1981 qemu_put_be32(f, vdev->config_len);
1982 qemu_put_buffer(f, vdev->config, vdev->config_len);
1983
1984 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1985 if (vdev->vq[i].vring.num == 0)
1986 break;
1987 }
1988
1989 qemu_put_be32(f, i);
1990
1991 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1992 if (vdev->vq[i].vring.num == 0)
1993 break;
1994
1995 qemu_put_be32(f, vdev->vq[i].vring.num);
1996 if (k->has_variable_vring_alignment) {
1997 qemu_put_be32(f, vdev->vq[i].vring.align);
1998 }
1999 /*
2000 * Save desc now, the rest of the ring addresses are saved in
2001 * subsections for VIRTIO-1 devices.
2002 */
2003 qemu_put_be64(f, vdev->vq[i].vring.desc);
2004 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx);
2005 if (k->save_queue) {
2006 k->save_queue(qbus->parent, i, f);
2007 }
2008 }
2009
2010 if (vdc->save != NULL) {
2011 vdc->save(vdev, f);
2012 }
2013
2014 if (vdc->vmsd) {
2015 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL);
2016 if (ret) {
2017 return ret;
2018 }
2019 }
2020
2021 /* Subsections */
2022 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL);
2023 }
2024
2025 /* A wrapper for use as a VMState .put function */
2026 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size,
2027 const VMStateField *field, QJSON *vmdesc)
2028 {
2029 return virtio_save(VIRTIO_DEVICE(opaque), f);
2030 }
2031
2032 /* A wrapper for use as a VMState .get function */
2033 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size,
2034 const VMStateField *field)
2035 {
2036 VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
2037 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev));
2038
2039 return virtio_load(vdev, f, dc->vmsd->version_id);
2040 }
2041
2042 const VMStateInfo virtio_vmstate_info = {
2043 .name = "virtio",
2044 .get = virtio_device_get,
2045 .put = virtio_device_put,
2046 };
2047
2048 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val)
2049 {
2050 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
2051 bool bad = (val & ~(vdev->host_features)) != 0;
2052
2053 val &= vdev->host_features;
2054 if (k->set_features) {
2055 k->set_features(vdev, val);
2056 }
2057 vdev->guest_features = val;
2058 return bad ? -1 : 0;
2059 }
2060
2061 int virtio_set_features(VirtIODevice *vdev, uint64_t val)
2062 {
2063 int ret;
2064 /*
2065 * The driver must not attempt to set features after feature negotiation
2066 * has finished.
2067 */
2068 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) {
2069 return -EINVAL;
2070 }
2071 ret = virtio_set_features_nocheck(vdev, val);
2072 if (!ret && virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
2073 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */
2074 int i;
2075 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
2076 if (vdev->vq[i].vring.num != 0) {
2077 virtio_init_region_cache(vdev, i);
2078 }
2079 }
2080 }
2081 return ret;
2082 }
2083
2084 size_t virtio_feature_get_config_size(VirtIOFeature *feature_sizes,
2085 uint64_t host_features)
2086 {
2087 size_t config_size = 0;
2088 int i;
2089
2090 for (i = 0; feature_sizes[i].flags != 0; i++) {
2091 if (host_features & feature_sizes[i].flags) {
2092 config_size = MAX(feature_sizes[i].end, config_size);
2093 }
2094 }
2095
2096 return config_size;
2097 }
2098
2099 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
2100 {
2101 int i, ret;
2102 int32_t config_len;
2103 uint32_t num;
2104 uint32_t features;
2105 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2106 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
2107 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
2108
2109 /*
2110 * We poison the endianness to ensure it does not get used before
2111 * subsections have been loaded.
2112 */
2113 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN;
2114
2115 if (k->load_config) {
2116 ret = k->load_config(qbus->parent, f);
2117 if (ret)
2118 return ret;
2119 }
2120
2121 qemu_get_8s(f, &vdev->status);
2122 qemu_get_8s(f, &vdev->isr);
2123 qemu_get_be16s(f, &vdev->queue_sel);
2124 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) {
2125 return -1;
2126 }
2127 qemu_get_be32s(f, &features);
2128
2129 /*
2130 * Temporarily set guest_features low bits - needed by
2131 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
2132 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ.
2133 *
2134 * Note: devices should always test host features in future - don't create
2135 * new dependencies like this.
2136 */
2137 vdev->guest_features = features;
2138
2139 config_len = qemu_get_be32(f);
2140
2141 /*
2142 * There are cases where the incoming config can be bigger or smaller
2143 * than what we have; so load what we have space for, and skip
2144 * any excess that's in the stream.
2145 */
2146 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len));
2147
2148 while (config_len > vdev->config_len) {
2149 qemu_get_byte(f);
2150 config_len--;
2151 }
2152
2153 num = qemu_get_be32(f);
2154
2155 if (num > VIRTIO_QUEUE_MAX) {
2156 error_report("Invalid number of virtqueues: 0x%x", num);
2157 return -1;
2158 }
2159
2160 for (i = 0; i < num; i++) {
2161 vdev->vq[i].vring.num = qemu_get_be32(f);
2162 if (k->has_variable_vring_alignment) {
2163 vdev->vq[i].vring.align = qemu_get_be32(f);
2164 }
2165 vdev->vq[i].vring.desc = qemu_get_be64(f);
2166 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx);
2167 vdev->vq[i].signalled_used_valid = false;
2168 vdev->vq[i].notification = true;
2169
2170 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) {
2171 error_report("VQ %d address 0x0 "
2172 "inconsistent with Host index 0x%x",
2173 i, vdev->vq[i].last_avail_idx);
2174 return -1;
2175 }
2176 if (k->load_queue) {
2177 ret = k->load_queue(qbus->parent, i, f);
2178 if (ret)
2179 return ret;
2180 }
2181 }
2182
2183 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR);
2184
2185 if (vdc->load != NULL) {
2186 ret = vdc->load(vdev, f, version_id);
2187 if (ret) {
2188 return ret;
2189 }
2190 }
2191
2192 if (vdc->vmsd) {
2193 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id);
2194 if (ret) {
2195 return ret;
2196 }
2197 }
2198
2199 /* Subsections */
2200 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1);
2201 if (ret) {
2202 return ret;
2203 }
2204
2205 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) {
2206 vdev->device_endian = virtio_default_endian();
2207 }
2208
2209 if (virtio_64bit_features_needed(vdev)) {
2210 /*
2211 * Subsection load filled vdev->guest_features. Run them
2212 * through virtio_set_features to sanity-check them against
2213 * host_features.
2214 */
2215 uint64_t features64 = vdev->guest_features;
2216 if (virtio_set_features_nocheck(vdev, features64) < 0) {
2217 error_report("Features 0x%" PRIx64 " unsupported. "
2218 "Allowed features: 0x%" PRIx64,
2219 features64, vdev->host_features);
2220 return -1;
2221 }
2222 } else {
2223 if (virtio_set_features_nocheck(vdev, features) < 0) {
2224 error_report("Features 0x%x unsupported. "
2225 "Allowed features: 0x%" PRIx64,
2226 features, vdev->host_features);
2227 return -1;
2228 }
2229 }
2230
2231 rcu_read_lock();
2232 for (i = 0; i < num; i++) {
2233 if (vdev->vq[i].vring.desc) {
2234 uint16_t nheads;
2235
2236 /*
2237 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so
2238 * only the region cache needs to be set up. Legacy devices need
2239 * to calculate used and avail ring addresses based on the desc
2240 * address.
2241 */
2242 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
2243 virtio_init_region_cache(vdev, i);
2244 } else {
2245 virtio_queue_update_rings(vdev, i);
2246 }
2247
2248 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx;
2249 /* Check it isn't doing strange things with descriptor numbers. */
2250 if (nheads > vdev->vq[i].vring.num) {
2251 error_report("VQ %d size 0x%x Guest index 0x%x "
2252 "inconsistent with Host index 0x%x: delta 0x%x",
2253 i, vdev->vq[i].vring.num,
2254 vring_avail_idx(&vdev->vq[i]),
2255 vdev->vq[i].last_avail_idx, nheads);
2256 return -1;
2257 }
2258 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]);
2259 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]);
2260
2261 /*
2262 * Some devices migrate VirtQueueElements that have been popped
2263 * from the avail ring but not yet returned to the used ring.
2264 * Since max ring size < UINT16_MAX it's safe to use modulo
2265 * UINT16_MAX + 1 subtraction.
2266 */
2267 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx -
2268 vdev->vq[i].used_idx);
2269 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) {
2270 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - "
2271 "used_idx 0x%x",
2272 i, vdev->vq[i].vring.num,
2273 vdev->vq[i].last_avail_idx,
2274 vdev->vq[i].used_idx);
2275 return -1;
2276 }
2277 }
2278 }
2279 rcu_read_unlock();
2280
2281 return 0;
2282 }
2283
2284 void virtio_cleanup(VirtIODevice *vdev)
2285 {
2286 qemu_del_vm_change_state_handler(vdev->vmstate);
2287 }
2288
2289 static void virtio_vmstate_change(void *opaque, int running, RunState state)
2290 {
2291 VirtIODevice *vdev = opaque;
2292 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2293 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
2294 bool backend_run = running && vdev->started;
2295 vdev->vm_running = running;
2296
2297 if (backend_run) {
2298 virtio_set_status(vdev, vdev->status);
2299 }
2300
2301 if (k->vmstate_change) {
2302 k->vmstate_change(qbus->parent, backend_run);
2303 }
2304
2305 if (!backend_run) {
2306 virtio_set_status(vdev, vdev->status);
2307 }
2308 }
2309
2310 void virtio_instance_init_common(Object *proxy_obj, void *data,
2311 size_t vdev_size, const char *vdev_name)
2312 {
2313 DeviceState *vdev = data;
2314
2315 object_initialize_child(proxy_obj, "virtio-backend", vdev, vdev_size,
2316 vdev_name, &error_abort, NULL);
2317 qdev_alias_all_properties(vdev, proxy_obj);
2318 }
2319
2320 void virtio_init(VirtIODevice *vdev, const char *name,
2321 uint16_t device_id, size_t config_size)
2322 {
2323 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2324 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
2325 int i;
2326 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0;
2327
2328 if (nvectors) {
2329 vdev->vector_queues =
2330 g_malloc0(sizeof(*vdev->vector_queues) * nvectors);
2331 }
2332
2333 vdev->start_on_kick = (virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
2334 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1));
2335 vdev->started = false;
2336 vdev->device_id = device_id;
2337 vdev->status = 0;
2338 atomic_set(&vdev->isr, 0);
2339 vdev->queue_sel = 0;
2340 vdev->config_vector = VIRTIO_NO_VECTOR;
2341 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX);
2342 vdev->vm_running = runstate_is_running();
2343 vdev->broken = false;
2344 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
2345 vdev->vq[i].vector = VIRTIO_NO_VECTOR;
2346 vdev->vq[i].vdev = vdev;
2347 vdev->vq[i].queue_index = i;
2348 }
2349
2350 vdev->name = name;
2351 vdev->config_len = config_size;
2352 if (vdev->config_len) {
2353 vdev->config = g_malloc0(config_size);
2354 } else {
2355 vdev->config = NULL;
2356 }
2357 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change,
2358 vdev);
2359 vdev->device_endian = virtio_default_endian();
2360 vdev->use_guest_notifier_mask = true;
2361 }
2362
2363 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)
2364 {
2365 return vdev->vq[n].vring.desc;
2366 }
2367
2368 bool virtio_queue_enabled(VirtIODevice *vdev, int n)
2369 {
2370 return virtio_queue_get_desc_addr(vdev, n) != 0;
2371 }
2372
2373 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n)
2374 {
2375 return vdev->vq[n].vring.avail;
2376 }
2377
2378 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n)
2379 {
2380 return vdev->vq[n].vring.used;
2381 }
2382
2383 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
2384 {
2385 return sizeof(VRingDesc) * vdev->vq[n].vring.num;
2386 }
2387
2388 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
2389 {
2390 return offsetof(VRingAvail, ring) +
2391 sizeof(uint16_t) * vdev->vq[n].vring.num;
2392 }
2393
2394 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
2395 {
2396 return offsetof(VRingUsed, ring) +
2397 sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
2398 }
2399
2400 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
2401 {
2402 return vdev->vq[n].last_avail_idx;
2403 }
2404
2405 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx)
2406 {
2407 vdev->vq[n].last_avail_idx = idx;
2408 vdev->vq[n].shadow_avail_idx = idx;
2409 }
2410
2411 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n)
2412 {
2413 rcu_read_lock();
2414 if (vdev->vq[n].vring.desc) {
2415 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]);
2416 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx;
2417 }
2418 rcu_read_unlock();
2419 }
2420
2421 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)
2422 {
2423 rcu_read_lock();
2424 if (vdev->vq[n].vring.desc) {
2425 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]);
2426 }
2427 rcu_read_unlock();
2428 }
2429
2430 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n)
2431 {
2432 vdev->vq[n].signalled_used_valid = false;
2433 }
2434
2435 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n)
2436 {
2437 return vdev->vq + n;
2438 }
2439
2440 uint16_t virtio_get_queue_index(VirtQueue *vq)
2441 {
2442 return vq->queue_index;
2443 }
2444
2445 static void virtio_queue_guest_notifier_read(EventNotifier *n)
2446 {
2447 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier);
2448 if (event_notifier_test_and_clear(n)) {
2449 virtio_irq(vq);
2450 }
2451 }
2452
2453 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
2454 bool with_irqfd)
2455 {
2456 if (assign && !with_irqfd) {
2457 event_notifier_set_handler(&vq->guest_notifier,
2458 virtio_queue_guest_notifier_read);
2459 } else {
2460 event_notifier_set_handler(&vq->guest_notifier, NULL);
2461 }
2462 if (!assign) {
2463 /* Test and clear notifier before closing it,
2464 * in case poll callback didn't have time to run. */
2465 virtio_queue_guest_notifier_read(&vq->guest_notifier);
2466 }
2467 }
2468
2469 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq)
2470 {
2471 return &vq->guest_notifier;
2472 }
2473
2474 static void virtio_queue_host_notifier_aio_read(EventNotifier *n)
2475 {
2476 VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
2477 if (event_notifier_test_and_clear(n)) {
2478 virtio_queue_notify_aio_vq(vq);
2479 }
2480 }
2481
2482 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n)
2483 {
2484 VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
2485
2486 virtio_queue_set_notification(vq, 0);
2487 }
2488
2489 static bool virtio_queue_host_notifier_aio_poll(void *opaque)
2490 {
2491 EventNotifier *n = opaque;
2492 VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
2493 bool progress;
2494
2495 if (!vq->vring.desc || virtio_queue_empty(vq)) {
2496 return false;
2497 }
2498
2499 progress = virtio_queue_notify_aio_vq(vq);
2500
2501 /* In case the handler function re-enabled notifications */
2502 virtio_queue_set_notification(vq, 0);
2503 return progress;
2504 }
2505
2506 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n)
2507 {
2508 VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
2509
2510 /* Caller polls once more after this to catch requests that race with us */
2511 virtio_queue_set_notification(vq, 1);
2512 }
2513
2514 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
2515 VirtIOHandleAIOOutput handle_output)
2516 {
2517 if (handle_output) {
2518 vq->handle_aio_output = handle_output;
2519 aio_set_event_notifier(ctx, &vq->host_notifier, true,
2520 virtio_queue_host_notifier_aio_read,
2521 virtio_queue_host_notifier_aio_poll);
2522 aio_set_event_notifier_poll(ctx, &vq->host_notifier,
2523 virtio_queue_host_notifier_aio_poll_begin,
2524 virtio_queue_host_notifier_aio_poll_end);
2525 } else {
2526 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL);
2527 /* Test and clear notifier before after disabling event,
2528 * in case poll callback didn't have time to run. */
2529 virtio_queue_host_notifier_aio_read(&vq->host_notifier);
2530 vq->handle_aio_output = NULL;
2531 }
2532 }
2533
2534 void virtio_queue_host_notifier_read(EventNotifier *n)
2535 {
2536 VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
2537 if (event_notifier_test_and_clear(n)) {
2538 virtio_queue_notify_vq(vq);
2539 }
2540 }
2541
2542 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
2543 {
2544 return &vq->host_notifier;
2545 }
2546
2547 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
2548 MemoryRegion *mr, bool assign)
2549 {
2550 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2551 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
2552
2553 if (k->set_host_notifier_mr) {
2554 return k->set_host_notifier_mr(qbus->parent, n, mr, assign);
2555 }
2556
2557 return -1;
2558 }
2559
2560 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name)
2561 {
2562 g_free(vdev->bus_name);
2563 vdev->bus_name = g_strdup(bus_name);
2564 }
2565
2566 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...)
2567 {
2568 va_list ap;
2569
2570 va_start(ap, fmt);
2571 error_vreport(fmt, ap);
2572 va_end(ap);
2573
2574 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
2575 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET;
2576 virtio_notify_config(vdev);
2577 }
2578
2579 vdev->broken = true;
2580 }
2581
2582 static void virtio_memory_listener_commit(MemoryListener *listener)
2583 {
2584 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener);
2585 int i;
2586
2587 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
2588 if (vdev->vq[i].vring.num == 0) {
2589 break;
2590 }
2591 virtio_init_region_cache(vdev, i);
2592 }
2593 }
2594
2595 static void virtio_device_realize(DeviceState *dev, Error **errp)
2596 {
2597 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
2598 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
2599 Error *err = NULL;
2600
2601 /* Devices should either use vmsd or the load/save methods */
2602 assert(!vdc->vmsd || !vdc->load);
2603
2604 if (vdc->realize != NULL) {
2605 vdc->realize(dev, &err);
2606 if (err != NULL) {
2607 error_propagate(errp, err);
2608 return;
2609 }
2610 }
2611
2612 virtio_bus_device_plugged(vdev, &err);
2613 if (err != NULL) {
2614 error_propagate(errp, err);
2615 vdc->unrealize(dev, NULL);
2616 return;
2617 }
2618
2619 vdev->listener.commit = virtio_memory_listener_commit;
2620 memory_listener_register(&vdev->listener, vdev->dma_as);
2621 }
2622
2623 static void virtio_device_unrealize(DeviceState *dev, Error **errp)
2624 {
2625 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
2626 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
2627 Error *err = NULL;
2628
2629 virtio_bus_device_unplugged(vdev);
2630
2631 if (vdc->unrealize != NULL) {
2632 vdc->unrealize(dev, &err);
2633 if (err != NULL) {
2634 error_propagate(errp, err);
2635 return;
2636 }
2637 }
2638
2639 g_free(vdev->bus_name);
2640 vdev->bus_name = NULL;
2641 }
2642
2643 static void virtio_device_free_virtqueues(VirtIODevice *vdev)
2644 {
2645 int i;
2646 if (!vdev->vq) {
2647 return;
2648 }
2649
2650 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
2651 if (vdev->vq[i].vring.num == 0) {
2652 break;
2653 }
2654 virtio_virtqueue_reset_region_cache(&vdev->vq[i]);
2655 }
2656 g_free(vdev->vq);
2657 }
2658
2659 static void virtio_device_instance_finalize(Object *obj)
2660 {
2661 VirtIODevice *vdev = VIRTIO_DEVICE(obj);
2662
2663 memory_listener_unregister(&vdev->listener);
2664 virtio_device_free_virtqueues(vdev);
2665
2666 g_free(vdev->config);
2667 g_free(vdev->vector_queues);
2668 }
2669
2670 static Property virtio_properties[] = {
2671 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features),
2672 DEFINE_PROP_END_OF_LIST(),
2673 };
2674
2675 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
2676 {
2677 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
2678 int i, n, r, err;
2679
2680 memory_region_transaction_begin();
2681 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
2682 VirtQueue *vq = &vdev->vq[n];
2683 if (!virtio_queue_get_num(vdev, n)) {
2684 continue;
2685 }
2686 r = virtio_bus_set_host_notifier(qbus, n, true);
2687 if (r < 0) {
2688 err = r;
2689 goto assign_error;
2690 }
2691 event_notifier_set_handler(&vq->host_notifier,
2692 virtio_queue_host_notifier_read);
2693 }
2694
2695 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
2696 /* Kick right away to begin processing requests already in vring */
2697 VirtQueue *vq = &vdev->vq[n];
2698 if (!vq->vring.num) {
2699 continue;
2700 }
2701 event_notifier_set(&vq->host_notifier);
2702 }
2703 memory_region_transaction_commit();
2704 return 0;
2705
2706 assign_error:
2707 i = n; /* save n for a second iteration after transaction is committed. */
2708 while (--n >= 0) {
2709 VirtQueue *vq = &vdev->vq[n];
2710 if (!virtio_queue_get_num(vdev, n)) {
2711 continue;
2712 }
2713
2714 event_notifier_set_handler(&vq->host_notifier, NULL);
2715 r = virtio_bus_set_host_notifier(qbus, n, false);
2716 assert(r >= 0);
2717 }
2718 memory_region_transaction_commit();
2719
2720 while (--i >= 0) {
2721 if (!virtio_queue_get_num(vdev, i)) {
2722 continue;
2723 }
2724 virtio_bus_cleanup_host_notifier(qbus, i);
2725 }
2726 return err;
2727 }
2728
2729 int virtio_device_start_ioeventfd(VirtIODevice *vdev)
2730 {
2731 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2732 VirtioBusState *vbus = VIRTIO_BUS(qbus);
2733
2734 return virtio_bus_start_ioeventfd(vbus);
2735 }
2736
2737 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
2738 {
2739 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
2740 int n, r;
2741
2742 memory_region_transaction_begin();
2743 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
2744 VirtQueue *vq = &vdev->vq[n];
2745
2746 if (!virtio_queue_get_num(vdev, n)) {
2747 continue;
2748 }
2749 event_notifier_set_handler(&vq->host_notifier, NULL);
2750 r = virtio_bus_set_host_notifier(qbus, n, false);
2751 assert(r >= 0);
2752 }
2753 memory_region_transaction_commit();
2754
2755 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
2756 if (!virtio_queue_get_num(vdev, n)) {
2757 continue;
2758 }
2759 virtio_bus_cleanup_host_notifier(qbus, n);
2760 }
2761 }
2762
2763 void virtio_device_stop_ioeventfd(VirtIODevice *vdev)
2764 {
2765 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2766 VirtioBusState *vbus = VIRTIO_BUS(qbus);
2767
2768 virtio_bus_stop_ioeventfd(vbus);
2769 }
2770
2771 int virtio_device_grab_ioeventfd(VirtIODevice *vdev)
2772 {
2773 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2774 VirtioBusState *vbus = VIRTIO_BUS(qbus);
2775
2776 return virtio_bus_grab_ioeventfd(vbus);
2777 }
2778
2779 void virtio_device_release_ioeventfd(VirtIODevice *vdev)
2780 {
2781 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2782 VirtioBusState *vbus = VIRTIO_BUS(qbus);
2783
2784 virtio_bus_release_ioeventfd(vbus);
2785 }
2786
2787 static void virtio_device_class_init(ObjectClass *klass, void *data)
2788 {
2789 /* Set the default value here. */
2790 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
2791 DeviceClass *dc = DEVICE_CLASS(klass);
2792
2793 dc->realize = virtio_device_realize;
2794 dc->unrealize = virtio_device_unrealize;
2795 dc->bus_type = TYPE_VIRTIO_BUS;
2796 dc->props = virtio_properties;
2797 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl;
2798 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl;
2799
2800 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES;
2801 }
2802
2803 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev)
2804 {
2805 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
2806 VirtioBusState *vbus = VIRTIO_BUS(qbus);
2807
2808 return virtio_bus_ioeventfd_enabled(vbus);
2809 }
2810
2811 static const TypeInfo virtio_device_info = {
2812 .name = TYPE_VIRTIO_DEVICE,
2813 .parent = TYPE_DEVICE,
2814 .instance_size = sizeof(VirtIODevice),
2815 .class_init = virtio_device_class_init,
2816 .instance_finalize = virtio_device_instance_finalize,
2817 .abstract = true,
2818 .class_size = sizeof(VirtioDeviceClass),
2819 };
2820
2821 static void virtio_register_types(void)
2822 {
2823 type_register_static(&virtio_device_info);
2824 }
2825
2826 type_init(virtio_register_types)
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