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libvhost-user: return early on virtqueue errors
[qemu/kevin.git] / contrib / libvhost-user / libvhost-user.c
blob4ebfa4cc40640f92797d6a34f1530f0886448c69
1 /*
2 * Vhost User library
3 *
4 * Copyright IBM, Corp. 2007
5 * Copyright (c) 2016 Red Hat, Inc.
6 *
7 * Authors:
8 * Anthony Liguori <aliguori@us.ibm.com>
9 * Marc-André Lureau <mlureau@redhat.com>
10 * Victor Kaplansky <victork@redhat.com>
11 *
12 * This work is licensed under the terms of the GNU GPL, version 2 or
13 * later. See the COPYING file in the top-level directory.
14 */
15
16 /* this code avoids GLib dependency */
17 #include <stdlib.h>
18 #include <stdio.h>
19 #include <unistd.h>
20 #include <stdarg.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <assert.h>
24 #include <inttypes.h>
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <sys/eventfd.h>
28 #include <sys/mman.h>
29 #include "qemu/compiler.h"
30
31 #if defined(__linux__)
32 #include <sys/syscall.h>
33 #include <fcntl.h>
34 #include <sys/ioctl.h>
35 #include <linux/vhost.h>
36
37 #ifdef __NR_userfaultfd
38 #include <linux/userfaultfd.h>
39 #endif
40
41 #endif
42
43 #include "qemu/atomic.h"
44 #include "qemu/osdep.h"
45 #include "qemu/bswap.h"
46 #include "qemu/memfd.h"
47
48 #include "libvhost-user.h"
49
50 /* usually provided by GLib */
51 #ifndef MIN
52 #define MIN(x, y) ({ \
53 typeof(x) _min1 = (x); \
54 typeof(y) _min2 = (y); \
55 (void) (&_min1 == &_min2); \
56 _min1 < _min2 ? _min1 : _min2; })
57 #endif
58
59 /* Round number down to multiple */
60 #define ALIGN_DOWN(n, m) ((n) / (m) * (m))
61
62 /* Round number up to multiple */
63 #define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
64
65 /* Align each region to cache line size in inflight buffer */
66 #define INFLIGHT_ALIGNMENT 64
67
68 /* The version of inflight buffer */
69 #define INFLIGHT_VERSION 1
70
71 #define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
72
73 /* The version of the protocol we support */
74 #define VHOST_USER_VERSION 1
75 #define LIBVHOST_USER_DEBUG 0
76
77 #define DPRINT(...) \
78 do { \
79 if (LIBVHOST_USER_DEBUG) { \
80 fprintf(stderr, __VA_ARGS__); \
81 } \
82 } while (0)
83
84 static inline
85 bool has_feature(uint64_t features, unsigned int fbit)
86 {
87 assert(fbit < 64);
88 return !!(features & (1ULL << fbit));
89 }
90
91 static inline
92 bool vu_has_feature(VuDev *dev,
93 unsigned int fbit)
94 {
95 return has_feature(dev->features, fbit);
96 }
97
98 static inline bool vu_has_protocol_feature(VuDev *dev, unsigned int fbit)
99 {
100 return has_feature(dev->protocol_features, fbit);
101 }
102
103 static const char *
104 vu_request_to_string(unsigned int req)
105 {
106 #define REQ(req) [req] = #req
107 static const char *vu_request_str[] = {
108 REQ(VHOST_USER_NONE),
109 REQ(VHOST_USER_GET_FEATURES),
110 REQ(VHOST_USER_SET_FEATURES),
111 REQ(VHOST_USER_SET_OWNER),
112 REQ(VHOST_USER_RESET_OWNER),
113 REQ(VHOST_USER_SET_MEM_TABLE),
114 REQ(VHOST_USER_SET_LOG_BASE),
115 REQ(VHOST_USER_SET_LOG_FD),
116 REQ(VHOST_USER_SET_VRING_NUM),
117 REQ(VHOST_USER_SET_VRING_ADDR),
118 REQ(VHOST_USER_SET_VRING_BASE),
119 REQ(VHOST_USER_GET_VRING_BASE),
120 REQ(VHOST_USER_SET_VRING_KICK),
121 REQ(VHOST_USER_SET_VRING_CALL),
122 REQ(VHOST_USER_SET_VRING_ERR),
123 REQ(VHOST_USER_GET_PROTOCOL_FEATURES),
124 REQ(VHOST_USER_SET_PROTOCOL_FEATURES),
125 REQ(VHOST_USER_GET_QUEUE_NUM),
126 REQ(VHOST_USER_SET_VRING_ENABLE),
127 REQ(VHOST_USER_SEND_RARP),
128 REQ(VHOST_USER_NET_SET_MTU),
129 REQ(VHOST_USER_SET_SLAVE_REQ_FD),
130 REQ(VHOST_USER_IOTLB_MSG),
131 REQ(VHOST_USER_SET_VRING_ENDIAN),
132 REQ(VHOST_USER_GET_CONFIG),
133 REQ(VHOST_USER_SET_CONFIG),
134 REQ(VHOST_USER_POSTCOPY_ADVISE),
135 REQ(VHOST_USER_POSTCOPY_LISTEN),
136 REQ(VHOST_USER_POSTCOPY_END),
137 REQ(VHOST_USER_GET_INFLIGHT_FD),
138 REQ(VHOST_USER_SET_INFLIGHT_FD),
139 REQ(VHOST_USER_GPU_SET_SOCKET),
140 REQ(VHOST_USER_VRING_KICK),
141 REQ(VHOST_USER_GET_MAX_MEM_SLOTS),
142 REQ(VHOST_USER_ADD_MEM_REG),
143 REQ(VHOST_USER_REM_MEM_REG),
144 REQ(VHOST_USER_MAX),
145 };
146 #undef REQ
147
148 if (req < VHOST_USER_MAX) {
149 return vu_request_str[req];
150 } else {
151 return "unknown";
152 }
153 }
154
155 static void
156 vu_panic(VuDev *dev, const char *msg, ...)
157 {
158 char *buf = NULL;
159 va_list ap;
160
161 va_start(ap, msg);
162 if (vasprintf(&buf, msg, ap) < 0) {
163 buf = NULL;
164 }
165 va_end(ap);
166
167 dev->broken = true;
168 dev->panic(dev, buf);
169 free(buf);
170
171 /*
172 * FIXME:
173 * find a way to call virtio_error, or perhaps close the connection?
174 */
175 }
176
177 /* Translate guest physical address to our virtual address. */
178 void *
179 vu_gpa_to_va(VuDev *dev, uint64_t *plen, uint64_t guest_addr)
180 {
181 int i;
182
183 if (*plen == 0) {
184 return NULL;
185 }
186
187 /* Find matching memory region. */
188 for (i = 0; i < dev->nregions; i++) {
189 VuDevRegion *r = &dev->regions[i];
190
191 if ((guest_addr >= r->gpa) && (guest_addr < (r->gpa + r->size))) {
192 if ((guest_addr + *plen) > (r->gpa + r->size)) {
193 *plen = r->gpa + r->size - guest_addr;
194 }
195 return (void *)(uintptr_t)
196 guest_addr - r->gpa + r->mmap_addr + r->mmap_offset;
197 }
198 }
199
200 return NULL;
201 }
202
203 /* Translate qemu virtual address to our virtual address. */
204 static void *
205 qva_to_va(VuDev *dev, uint64_t qemu_addr)
206 {
207 int i;
208
209 /* Find matching memory region. */
210 for (i = 0; i < dev->nregions; i++) {
211 VuDevRegion *r = &dev->regions[i];
212
213 if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
214 return (void *)(uintptr_t)
215 qemu_addr - r->qva + r->mmap_addr + r->mmap_offset;
216 }
217 }
218
219 return NULL;
220 }
221
222 static void
223 vmsg_close_fds(VhostUserMsg *vmsg)
224 {
225 int i;
226
227 for (i = 0; i < vmsg->fd_num; i++) {
228 close(vmsg->fds[i]);
229 }
230 }
231
232 /* Set reply payload.u64 and clear request flags and fd_num */
233 static void vmsg_set_reply_u64(VhostUserMsg *vmsg, uint64_t val)
234 {
235 vmsg->flags = 0; /* defaults will be set by vu_send_reply() */
236 vmsg->size = sizeof(vmsg->payload.u64);
237 vmsg->payload.u64 = val;
238 vmsg->fd_num = 0;
239 }
240
241 /* A test to see if we have userfault available */
242 static bool
243 have_userfault(void)
244 {
245 #if defined(__linux__) && defined(__NR_userfaultfd) &&\
246 defined(UFFD_FEATURE_MISSING_SHMEM) &&\
247 defined(UFFD_FEATURE_MISSING_HUGETLBFS)
248 /* Now test the kernel we're running on really has the features */
249 int ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
250 struct uffdio_api api_struct;
251 if (ufd < 0) {
252 return false;
253 }
254
255 api_struct.api = UFFD_API;
256 api_struct.features = UFFD_FEATURE_MISSING_SHMEM |
257 UFFD_FEATURE_MISSING_HUGETLBFS;
258 if (ioctl(ufd, UFFDIO_API, &api_struct)) {
259 close(ufd);
260 return false;
261 }
262 close(ufd);
263 return true;
264
265 #else
266 return false;
267 #endif
268 }
269
270 static bool
271 vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
272 {
273 char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
274 struct iovec iov = {
275 .iov_base = (char *)vmsg,
276 .iov_len = VHOST_USER_HDR_SIZE,
277 };
278 struct msghdr msg = {
279 .msg_iov = &iov,
280 .msg_iovlen = 1,
281 .msg_control = control,
282 .msg_controllen = sizeof(control),
283 };
284 size_t fd_size;
285 struct cmsghdr *cmsg;
286 int rc;
287
288 do {
289 rc = recvmsg(conn_fd, &msg, 0);
290 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
291
292 if (rc < 0) {
293 vu_panic(dev, "Error while recvmsg: %s", strerror(errno));
294 return false;
295 }
296
297 vmsg->fd_num = 0;
298 for (cmsg = CMSG_FIRSTHDR(&msg);
299 cmsg != NULL;
300 cmsg = CMSG_NXTHDR(&msg, cmsg))
301 {
302 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
303 fd_size = cmsg->cmsg_len - CMSG_LEN(0);
304 vmsg->fd_num = fd_size / sizeof(int);
305 memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
306 break;
307 }
308 }
309
310 if (vmsg->size > sizeof(vmsg->payload)) {
311 vu_panic(dev,
312 "Error: too big message request: %d, size: vmsg->size: %u, "
313 "while sizeof(vmsg->payload) = %zu\n",
314 vmsg->request, vmsg->size, sizeof(vmsg->payload));
315 goto fail;
316 }
317
318 if (vmsg->size) {
319 do {
320 rc = read(conn_fd, &vmsg->payload, vmsg->size);
321 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
322
323 if (rc <= 0) {
324 vu_panic(dev, "Error while reading: %s", strerror(errno));
325 goto fail;
326 }
327
328 assert(rc == vmsg->size);
329 }
330
331 return true;
332
333 fail:
334 vmsg_close_fds(vmsg);
335
336 return false;
337 }
338
339 static bool
340 vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
341 {
342 int rc;
343 uint8_t *p = (uint8_t *)vmsg;
344 char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
345 struct iovec iov = {
346 .iov_base = (char *)vmsg,
347 .iov_len = VHOST_USER_HDR_SIZE,
348 };
349 struct msghdr msg = {
350 .msg_iov = &iov,
351 .msg_iovlen = 1,
352 .msg_control = control,
353 };
354 struct cmsghdr *cmsg;
355
356 memset(control, 0, sizeof(control));
357 assert(vmsg->fd_num <= VHOST_MEMORY_BASELINE_NREGIONS);
358 if (vmsg->fd_num > 0) {
359 size_t fdsize = vmsg->fd_num * sizeof(int);
360 msg.msg_controllen = CMSG_SPACE(fdsize);
361 cmsg = CMSG_FIRSTHDR(&msg);
362 cmsg->cmsg_len = CMSG_LEN(fdsize);
363 cmsg->cmsg_level = SOL_SOCKET;
364 cmsg->cmsg_type = SCM_RIGHTS;
365 memcpy(CMSG_DATA(cmsg), vmsg->fds, fdsize);
366 } else {
367 msg.msg_controllen = 0;
368 }
369
370 do {
371 rc = sendmsg(conn_fd, &msg, 0);
372 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
373
374 if (vmsg->size) {
375 do {
376 if (vmsg->data) {
377 rc = write(conn_fd, vmsg->data, vmsg->size);
378 } else {
379 rc = write(conn_fd, p + VHOST_USER_HDR_SIZE, vmsg->size);
380 }
381 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
382 }
383
384 if (rc <= 0) {
385 vu_panic(dev, "Error while writing: %s", strerror(errno));
386 return false;
387 }
388
389 return true;
390 }
391
392 static bool
393 vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
394 {
395 /* Set the version in the flags when sending the reply */
396 vmsg->flags &= ~VHOST_USER_VERSION_MASK;
397 vmsg->flags |= VHOST_USER_VERSION;
398 vmsg->flags |= VHOST_USER_REPLY_MASK;
399
400 return vu_message_write(dev, conn_fd, vmsg);
401 }
402
403 /*
404 * Processes a reply on the slave channel.
405 * Entered with slave_mutex held and releases it before exit.
406 * Returns true on success.
407 */
408 static bool
409 vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
410 {
411 VhostUserMsg msg_reply;
412 bool result = false;
413
414 if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
415 result = true;
416 goto out;
417 }
418
419 if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) {
420 goto out;
421 }
422
423 if (msg_reply.request != vmsg->request) {
424 DPRINT("Received unexpected msg type. Expected %d received %d",
425 vmsg->request, msg_reply.request);
426 goto out;
427 }
428
429 result = msg_reply.payload.u64 == 0;
430
431 out:
432 pthread_mutex_unlock(&dev->slave_mutex);
433 return result;
434 }
435
436 /* Kick the log_call_fd if required. */
437 static void
438 vu_log_kick(VuDev *dev)
439 {
440 if (dev->log_call_fd != -1) {
441 DPRINT("Kicking the QEMU's log...\n");
442 if (eventfd_write(dev->log_call_fd, 1) < 0) {
443 vu_panic(dev, "Error writing eventfd: %s", strerror(errno));
444 }
445 }
446 }
447
448 static void
449 vu_log_page(uint8_t *log_table, uint64_t page)
450 {
451 DPRINT("Logged dirty guest page: %"PRId64"\n", page);
452 qatomic_or(&log_table[page / 8], 1 << (page % 8));
453 }
454
455 static void
456 vu_log_write(VuDev *dev, uint64_t address, uint64_t length)
457 {
458 uint64_t page;
459
460 if (!(dev->features & (1ULL << VHOST_F_LOG_ALL)) ||
461 !dev->log_table || !length) {
462 return;
463 }
464
465 assert(dev->log_size > ((address + length - 1) / VHOST_LOG_PAGE / 8));
466
467 page = address / VHOST_LOG_PAGE;
468 while (page * VHOST_LOG_PAGE < address + length) {
469 vu_log_page(dev->log_table, page);
470 page += 1;
471 }
472
473 vu_log_kick(dev);
474 }
475
476 static void
477 vu_kick_cb(VuDev *dev, int condition, void *data)
478 {
479 int index = (intptr_t)data;
480 VuVirtq *vq = &dev->vq[index];
481 int sock = vq->kick_fd;
482 eventfd_t kick_data;
483 ssize_t rc;
484
485 rc = eventfd_read(sock, &kick_data);
486 if (rc == -1) {
487 vu_panic(dev, "kick eventfd_read(): %s", strerror(errno));
488 dev->remove_watch(dev, dev->vq[index].kick_fd);
489 } else {
490 DPRINT("Got kick_data: %016"PRIx64" handler:%p idx:%d\n",
491 kick_data, vq->handler, index);
492 if (vq->handler) {
493 vq->handler(dev, index);
494 }
495 }
496 }
497
498 static bool
499 vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg)
500 {
501 vmsg->payload.u64 =
502 /*
503 * The following VIRTIO feature bits are supported by our virtqueue
504 * implementation:
505 */
506 1ULL << VIRTIO_F_NOTIFY_ON_EMPTY |
507 1ULL << VIRTIO_RING_F_INDIRECT_DESC |
508 1ULL << VIRTIO_RING_F_EVENT_IDX |
509 1ULL << VIRTIO_F_VERSION_1 |
510
511 /* vhost-user feature bits */
512 1ULL << VHOST_F_LOG_ALL |
513 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
514
515 if (dev->iface->get_features) {
516 vmsg->payload.u64 |= dev->iface->get_features(dev);
517 }
518
519 vmsg->size = sizeof(vmsg->payload.u64);
520 vmsg->fd_num = 0;
521
522 DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
523
524 return true;
525 }
526
527 static void
528 vu_set_enable_all_rings(VuDev *dev, bool enabled)
529 {
530 uint16_t i;
531
532 for (i = 0; i < dev->max_queues; i++) {
533 dev->vq[i].enable = enabled;
534 }
535 }
536
537 static bool
538 vu_set_features_exec(VuDev *dev, VhostUserMsg *vmsg)
539 {
540 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
541
542 dev->features = vmsg->payload.u64;
543 if (!vu_has_feature(dev, VIRTIO_F_VERSION_1)) {
544 /*
545 * We only support devices conforming to VIRTIO 1.0 or
546 * later
547 */
548 vu_panic(dev, "virtio legacy devices aren't supported by libvhost-user");
549 return false;
550 }
551
552 if (!(dev->features & VHOST_USER_F_PROTOCOL_FEATURES)) {
553 vu_set_enable_all_rings(dev, true);
554 }
555
556 if (dev->iface->set_features) {
557 dev->iface->set_features(dev, dev->features);
558 }
559
560 return false;
561 }
562
563 static bool
564 vu_set_owner_exec(VuDev *dev, VhostUserMsg *vmsg)
565 {
566 return false;
567 }
568
569 static void
570 vu_close_log(VuDev *dev)
571 {
572 if (dev->log_table) {
573 if (munmap(dev->log_table, dev->log_size) != 0) {
574 perror("close log munmap() error");
575 }
576
577 dev->log_table = NULL;
578 }
579 if (dev->log_call_fd != -1) {
580 close(dev->log_call_fd);
581 dev->log_call_fd = -1;
582 }
583 }
584
585 static bool
586 vu_reset_device_exec(VuDev *dev, VhostUserMsg *vmsg)
587 {
588 vu_set_enable_all_rings(dev, false);
589
590 return false;
591 }
592
593 static bool
594 map_ring(VuDev *dev, VuVirtq *vq)
595 {
596 vq->vring.desc = qva_to_va(dev, vq->vra.desc_user_addr);
597 vq->vring.used = qva_to_va(dev, vq->vra.used_user_addr);
598 vq->vring.avail = qva_to_va(dev, vq->vra.avail_user_addr);
599
600 DPRINT("Setting virtq addresses:\n");
601 DPRINT(" vring_desc at %p\n", vq->vring.desc);
602 DPRINT(" vring_used at %p\n", vq->vring.used);
603 DPRINT(" vring_avail at %p\n", vq->vring.avail);
604
605 return !(vq->vring.desc && vq->vring.used && vq->vring.avail);
606 }
607
608 static bool
609 generate_faults(VuDev *dev) {
610 int i;
611 for (i = 0; i < dev->nregions; i++) {
612 VuDevRegion *dev_region = &dev->regions[i];
613 int ret;
614 #ifdef UFFDIO_REGISTER
615 /*
616 * We should already have an open ufd. Mark each memory
617 * range as ufd.
618 * Discard any mapping we have here; note I can't use MADV_REMOVE
619 * or fallocate to make the hole since I don't want to lose
620 * data that's already arrived in the shared process.
621 * TODO: How to do hugepage
622 */
623 ret = madvise((void *)(uintptr_t)dev_region->mmap_addr,
624 dev_region->size + dev_region->mmap_offset,
625 MADV_DONTNEED);
626 if (ret) {
627 fprintf(stderr,
628 "%s: Failed to madvise(DONTNEED) region %d: %s\n",
629 __func__, i, strerror(errno));
630 }
631 /*
632 * Turn off transparent hugepages so we dont get lose wakeups
633 * in neighbouring pages.
634 * TODO: Turn this backon later.
635 */
636 ret = madvise((void *)(uintptr_t)dev_region->mmap_addr,
637 dev_region->size + dev_region->mmap_offset,
638 MADV_NOHUGEPAGE);
639 if (ret) {
640 /*
641 * Note: This can happen legally on kernels that are configured
642 * without madvise'able hugepages
643 */
644 fprintf(stderr,
645 "%s: Failed to madvise(NOHUGEPAGE) region %d: %s\n",
646 __func__, i, strerror(errno));
647 }
648 struct uffdio_register reg_struct;
649 reg_struct.range.start = (uintptr_t)dev_region->mmap_addr;
650 reg_struct.range.len = dev_region->size + dev_region->mmap_offset;
651 reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
652
653 if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER, &reg_struct)) {
654 vu_panic(dev, "%s: Failed to userfault region %d "
655 "@%p + size:%zx offset: %zx: (ufd=%d)%s\n",
656 __func__, i,
657 dev_region->mmap_addr,
658 dev_region->size, dev_region->mmap_offset,
659 dev->postcopy_ufd, strerror(errno));
660 return false;
661 }
662 if (!(reg_struct.ioctls & ((__u64)1 << _UFFDIO_COPY))) {
663 vu_panic(dev, "%s Region (%d) doesn't support COPY",
664 __func__, i);
665 return false;
666 }
667 DPRINT("%s: region %d: Registered userfault for %"
668 PRIx64 " + %" PRIx64 "\n", __func__, i,
669 (uint64_t)reg_struct.range.start,
670 (uint64_t)reg_struct.range.len);
671 /* Now it's registered we can let the client at it */
672 if (mprotect((void *)(uintptr_t)dev_region->mmap_addr,
673 dev_region->size + dev_region->mmap_offset,
674 PROT_READ | PROT_WRITE)) {
675 vu_panic(dev, "failed to mprotect region %d for postcopy (%s)",
676 i, strerror(errno));
677 return false;
678 }
679 /* TODO: Stash 'zero' support flags somewhere */
680 #endif
681 }
682
683 return true;
684 }
685
686 static bool
687 vu_add_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
688 int i;
689 bool track_ramblocks = dev->postcopy_listening;
690 VhostUserMemoryRegion m = vmsg->payload.memreg.region, *msg_region = &m;
691 VuDevRegion *dev_region = &dev->regions[dev->nregions];
692 void *mmap_addr;
693
694 /*
695 * If we are in postcopy mode and we receive a u64 payload with a 0 value
696 * we know all the postcopy client bases have been received, and we
697 * should start generating faults.
698 */
699 if (track_ramblocks &&
700 vmsg->size == sizeof(vmsg->payload.u64) &&
701 vmsg->payload.u64 == 0) {
702 (void)generate_faults(dev);
703 return false;
704 }
705
706 DPRINT("Adding region: %d\n", dev->nregions);
707 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
708 msg_region->guest_phys_addr);
709 DPRINT(" memory_size: 0x%016"PRIx64"\n",
710 msg_region->memory_size);
711 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
712 msg_region->userspace_addr);
713 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
714 msg_region->mmap_offset);
715
716 dev_region->gpa = msg_region->guest_phys_addr;
717 dev_region->size = msg_region->memory_size;
718 dev_region->qva = msg_region->userspace_addr;
719 dev_region->mmap_offset = msg_region->mmap_offset;
720
721 /*
722 * We don't use offset argument of mmap() since the
723 * mapped address has to be page aligned, and we use huge
724 * pages.
725 */
726 if (track_ramblocks) {
727 /*
728 * In postcopy we're using PROT_NONE here to catch anyone
729 * accessing it before we userfault.
730 */
731 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
732 PROT_NONE, MAP_SHARED,
733 vmsg->fds[0], 0);
734 } else {
735 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
736 PROT_READ | PROT_WRITE, MAP_SHARED, vmsg->fds[0],
737 0);
738 }
739
740 if (mmap_addr == MAP_FAILED) {
741 vu_panic(dev, "region mmap error: %s", strerror(errno));
742 } else {
743 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
744 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
745 dev_region->mmap_addr);
746 }
747
748 close(vmsg->fds[0]);
749
750 if (track_ramblocks) {
751 /*
752 * Return the address to QEMU so that it can translate the ufd
753 * fault addresses back.
754 */
755 msg_region->userspace_addr = (uintptr_t)(mmap_addr +
756 dev_region->mmap_offset);
757
758 /* Send the message back to qemu with the addresses filled in. */
759 vmsg->fd_num = 0;
760 if (!vu_send_reply(dev, dev->sock, vmsg)) {
761 vu_panic(dev, "failed to respond to add-mem-region for postcopy");
762 return false;
763 }
764
765 DPRINT("Successfully added new region in postcopy\n");
766 dev->nregions++;
767 return false;
768
769 } else {
770 for (i = 0; i < dev->max_queues; i++) {
771 if (dev->vq[i].vring.desc) {
772 if (map_ring(dev, &dev->vq[i])) {
773 vu_panic(dev, "remapping queue %d for new memory region",
774 i);
775 }
776 }
777 }
778
779 DPRINT("Successfully added new region\n");
780 dev->nregions++;
781 vmsg_set_reply_u64(vmsg, 0);
782 return true;
783 }
784 }
785
786 static inline bool reg_equal(VuDevRegion *vudev_reg,
787 VhostUserMemoryRegion *msg_reg)
788 {
789 if (vudev_reg->gpa == msg_reg->guest_phys_addr &&
790 vudev_reg->qva == msg_reg->userspace_addr &&
791 vudev_reg->size == msg_reg->memory_size) {
792 return true;
793 }
794
795 return false;
796 }
797
798 static bool
799 vu_rem_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
800 int i, j;
801 bool found = false;
802 VuDevRegion shadow_regions[VHOST_USER_MAX_RAM_SLOTS] = {};
803 VhostUserMemoryRegion m = vmsg->payload.memreg.region, *msg_region = &m;
804
805 DPRINT("Removing region:\n");
806 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
807 msg_region->guest_phys_addr);
808 DPRINT(" memory_size: 0x%016"PRIx64"\n",
809 msg_region->memory_size);
810 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
811 msg_region->userspace_addr);
812 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
813 msg_region->mmap_offset);
814
815 for (i = 0, j = 0; i < dev->nregions; i++) {
816 if (!reg_equal(&dev->regions[i], msg_region)) {
817 shadow_regions[j].gpa = dev->regions[i].gpa;
818 shadow_regions[j].size = dev->regions[i].size;
819 shadow_regions[j].qva = dev->regions[i].qva;
820 shadow_regions[j].mmap_offset = dev->regions[i].mmap_offset;
821 j++;
822 } else {
823 found = true;
824 VuDevRegion *r = &dev->regions[i];
825 void *m = (void *) (uintptr_t) r->mmap_addr;
826
827 if (m) {
828 munmap(m, r->size + r->mmap_offset);
829 }
830 }
831 }
832
833 if (found) {
834 memcpy(dev->regions, shadow_regions,
835 sizeof(VuDevRegion) * VHOST_USER_MAX_RAM_SLOTS);
836 DPRINT("Successfully removed a region\n");
837 dev->nregions--;
838 vmsg_set_reply_u64(vmsg, 0);
839 } else {
840 vu_panic(dev, "Specified region not found\n");
841 }
842
843 return true;
844 }
845
846 static bool
847 vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
848 {
849 int i;
850 VhostUserMemory m = vmsg->payload.memory, *memory = &m;
851 dev->nregions = memory->nregions;
852
853 DPRINT("Nregions: %d\n", memory->nregions);
854 for (i = 0; i < dev->nregions; i++) {
855 void *mmap_addr;
856 VhostUserMemoryRegion *msg_region = &memory->regions[i];
857 VuDevRegion *dev_region = &dev->regions[i];
858
859 DPRINT("Region %d\n", i);
860 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
861 msg_region->guest_phys_addr);
862 DPRINT(" memory_size: 0x%016"PRIx64"\n",
863 msg_region->memory_size);
864 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
865 msg_region->userspace_addr);
866 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
867 msg_region->mmap_offset);
868
869 dev_region->gpa = msg_region->guest_phys_addr;
870 dev_region->size = msg_region->memory_size;
871 dev_region->qva = msg_region->userspace_addr;
872 dev_region->mmap_offset = msg_region->mmap_offset;
873
874 /* We don't use offset argument of mmap() since the
875 * mapped address has to be page aligned, and we use huge
876 * pages.
877 * In postcopy we're using PROT_NONE here to catch anyone
878 * accessing it before we userfault
879 */
880 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
881 PROT_NONE, MAP_SHARED,
882 vmsg->fds[i], 0);
883
884 if (mmap_addr == MAP_FAILED) {
885 vu_panic(dev, "region mmap error: %s", strerror(errno));
886 } else {
887 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
888 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
889 dev_region->mmap_addr);
890 }
891
892 /* Return the address to QEMU so that it can translate the ufd
893 * fault addresses back.
894 */
895 msg_region->userspace_addr = (uintptr_t)(mmap_addr +
896 dev_region->mmap_offset);
897 close(vmsg->fds[i]);
898 }
899
900 /* Send the message back to qemu with the addresses filled in */
901 vmsg->fd_num = 0;
902 if (!vu_send_reply(dev, dev->sock, vmsg)) {
903 vu_panic(dev, "failed to respond to set-mem-table for postcopy");
904 return false;
905 }
906
907 /* Wait for QEMU to confirm that it's registered the handler for the
908 * faults.
909 */
910 if (!vu_message_read(dev, dev->sock, vmsg) ||
911 vmsg->size != sizeof(vmsg->payload.u64) ||
912 vmsg->payload.u64 != 0) {
913 vu_panic(dev, "failed to receive valid ack for postcopy set-mem-table");
914 return false;
915 }
916
917 /* OK, now we can go and register the memory and generate faults */
918 (void)generate_faults(dev);
919
920 return false;
921 }
922
923 static bool
924 vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg)
925 {
926 int i;
927 VhostUserMemory m = vmsg->payload.memory, *memory = &m;
928
929 for (i = 0; i < dev->nregions; i++) {
930 VuDevRegion *r = &dev->regions[i];
931 void *m = (void *) (uintptr_t) r->mmap_addr;
932
933 if (m) {
934 munmap(m, r->size + r->mmap_offset);
935 }
936 }
937 dev->nregions = memory->nregions;
938
939 if (dev->postcopy_listening) {
940 return vu_set_mem_table_exec_postcopy(dev, vmsg);
941 }
942
943 DPRINT("Nregions: %d\n", memory->nregions);
944 for (i = 0; i < dev->nregions; i++) {
945 void *mmap_addr;
946 VhostUserMemoryRegion *msg_region = &memory->regions[i];
947 VuDevRegion *dev_region = &dev->regions[i];
948
949 DPRINT("Region %d\n", i);
950 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
951 msg_region->guest_phys_addr);
952 DPRINT(" memory_size: 0x%016"PRIx64"\n",
953 msg_region->memory_size);
954 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
955 msg_region->userspace_addr);
956 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
957 msg_region->mmap_offset);
958
959 dev_region->gpa = msg_region->guest_phys_addr;
960 dev_region->size = msg_region->memory_size;
961 dev_region->qva = msg_region->userspace_addr;
962 dev_region->mmap_offset = msg_region->mmap_offset;
963
964 /* We don't use offset argument of mmap() since the
965 * mapped address has to be page aligned, and we use huge
966 * pages. */
967 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
968 PROT_READ | PROT_WRITE, MAP_SHARED,
969 vmsg->fds[i], 0);
970
971 if (mmap_addr == MAP_FAILED) {
972 vu_panic(dev, "region mmap error: %s", strerror(errno));
973 } else {
974 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
975 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
976 dev_region->mmap_addr);
977 }
978
979 close(vmsg->fds[i]);
980 }
981
982 for (i = 0; i < dev->max_queues; i++) {
983 if (dev->vq[i].vring.desc) {
984 if (map_ring(dev, &dev->vq[i])) {
985 vu_panic(dev, "remapping queue %d during setmemtable", i);
986 }
987 }
988 }
989
990 return false;
991 }
992
993 static bool
994 vu_set_log_base_exec(VuDev *dev, VhostUserMsg *vmsg)
995 {
996 int fd;
997 uint64_t log_mmap_size, log_mmap_offset;
998 void *rc;
999
1000 if (vmsg->fd_num != 1 ||
1001 vmsg->size != sizeof(vmsg->payload.log)) {
1002 vu_panic(dev, "Invalid log_base message");
1003 return true;
1004 }
1005
1006 fd = vmsg->fds[0];
1007 log_mmap_offset = vmsg->payload.log.mmap_offset;
1008 log_mmap_size = vmsg->payload.log.mmap_size;
1009 DPRINT("Log mmap_offset: %"PRId64"\n", log_mmap_offset);
1010 DPRINT("Log mmap_size: %"PRId64"\n", log_mmap_size);
1011
1012 rc = mmap(0, log_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
1013 log_mmap_offset);
1014 close(fd);
1015 if (rc == MAP_FAILED) {
1016 perror("log mmap error");
1017 }
1018
1019 if (dev->log_table) {
1020 munmap(dev->log_table, dev->log_size);
1021 }
1022 dev->log_table = rc;
1023 dev->log_size = log_mmap_size;
1024
1025 vmsg->size = sizeof(vmsg->payload.u64);
1026 vmsg->fd_num = 0;
1027
1028 return true;
1029 }
1030
1031 static bool
1032 vu_set_log_fd_exec(VuDev *dev, VhostUserMsg *vmsg)
1033 {
1034 if (vmsg->fd_num != 1) {
1035 vu_panic(dev, "Invalid log_fd message");
1036 return false;
1037 }
1038
1039 if (dev->log_call_fd != -1) {
1040 close(dev->log_call_fd);
1041 }
1042 dev->log_call_fd = vmsg->fds[0];
1043 DPRINT("Got log_call_fd: %d\n", vmsg->fds[0]);
1044
1045 return false;
1046 }
1047
1048 static bool
1049 vu_set_vring_num_exec(VuDev *dev, VhostUserMsg *vmsg)
1050 {
1051 unsigned int index = vmsg->payload.state.index;
1052 unsigned int num = vmsg->payload.state.num;
1053
1054 DPRINT("State.index: %d\n", index);
1055 DPRINT("State.num: %d\n", num);
1056 dev->vq[index].vring.num = num;
1057
1058 return false;
1059 }
1060
1061 static bool
1062 vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg)
1063 {
1064 struct vhost_vring_addr addr = vmsg->payload.addr, *vra = &addr;
1065 unsigned int index = vra->index;
1066 VuVirtq *vq = &dev->vq[index];
1067
1068 DPRINT("vhost_vring_addr:\n");
1069 DPRINT(" index: %d\n", vra->index);
1070 DPRINT(" flags: %d\n", vra->flags);
1071 DPRINT(" desc_user_addr: 0x%016" PRIx64 "\n", vra->desc_user_addr);
1072 DPRINT(" used_user_addr: 0x%016" PRIx64 "\n", vra->used_user_addr);
1073 DPRINT(" avail_user_addr: 0x%016" PRIx64 "\n", vra->avail_user_addr);
1074 DPRINT(" log_guest_addr: 0x%016" PRIx64 "\n", vra->log_guest_addr);
1075
1076 vq->vra = *vra;
1077 vq->vring.flags = vra->flags;
1078 vq->vring.log_guest_addr = vra->log_guest_addr;
1079
1080
1081 if (map_ring(dev, vq)) {
1082 vu_panic(dev, "Invalid vring_addr message");
1083 return false;
1084 }
1085
1086 vq->used_idx = lduw_le_p(&vq->vring.used->idx);
1087
1088 if (vq->last_avail_idx != vq->used_idx) {
1089 bool resume = dev->iface->queue_is_processed_in_order &&
1090 dev->iface->queue_is_processed_in_order(dev, index);
1091
1092 DPRINT("Last avail index != used index: %u != %u%s\n",
1093 vq->last_avail_idx, vq->used_idx,
1094 resume ? ", resuming" : "");
1095
1096 if (resume) {
1097 vq->shadow_avail_idx = vq->last_avail_idx = vq->used_idx;
1098 }
1099 }
1100
1101 return false;
1102 }
1103
1104 static bool
1105 vu_set_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1106 {
1107 unsigned int index = vmsg->payload.state.index;
1108 unsigned int num = vmsg->payload.state.num;
1109
1110 DPRINT("State.index: %d\n", index);
1111 DPRINT("State.num: %d\n", num);
1112 dev->vq[index].shadow_avail_idx = dev->vq[index].last_avail_idx = num;
1113
1114 return false;
1115 }
1116
1117 static bool
1118 vu_get_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1119 {
1120 unsigned int index = vmsg->payload.state.index;
1121
1122 DPRINT("State.index: %d\n", index);
1123 vmsg->payload.state.num = dev->vq[index].last_avail_idx;
1124 vmsg->size = sizeof(vmsg->payload.state);
1125
1126 dev->vq[index].started = false;
1127 if (dev->iface->queue_set_started) {
1128 dev->iface->queue_set_started(dev, index, false);
1129 }
1130
1131 if (dev->vq[index].call_fd != -1) {
1132 close(dev->vq[index].call_fd);
1133 dev->vq[index].call_fd = -1;
1134 }
1135 if (dev->vq[index].kick_fd != -1) {
1136 dev->remove_watch(dev, dev->vq[index].kick_fd);
1137 close(dev->vq[index].kick_fd);
1138 dev->vq[index].kick_fd = -1;
1139 }
1140
1141 return true;
1142 }
1143
1144 static bool
1145 vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
1146 {
1147 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1148 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1149
1150 if (index >= dev->max_queues) {
1151 vmsg_close_fds(vmsg);
1152 vu_panic(dev, "Invalid queue index: %u", index);
1153 return false;
1154 }
1155
1156 if (nofd) {
1157 vmsg_close_fds(vmsg);
1158 return true;
1159 }
1160
1161 if (vmsg->fd_num != 1) {
1162 vmsg_close_fds(vmsg);
1163 vu_panic(dev, "Invalid fds in request: %d", vmsg->request);
1164 return false;
1165 }
1166
1167 return true;
1168 }
1169
1170 static int
1171 inflight_desc_compare(const void *a, const void *b)
1172 {
1173 VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
1174 *desc1 = (VuVirtqInflightDesc *)b;
1175
1176 if (desc1->counter > desc0->counter &&
1177 (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
1178 return 1;
1179 }
1180
1181 return -1;
1182 }
1183
1184 static int
1185 vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
1186 {
1187 int i = 0;
1188
1189 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
1190 return 0;
1191 }
1192
1193 if (unlikely(!vq->inflight)) {
1194 return -1;
1195 }
1196
1197 if (unlikely(!vq->inflight->version)) {
1198 /* initialize the buffer */
1199 vq->inflight->version = INFLIGHT_VERSION;
1200 return 0;
1201 }
1202
1203 vq->used_idx = lduw_le_p(&vq->vring.used->idx);
1204 vq->resubmit_num = 0;
1205 vq->resubmit_list = NULL;
1206 vq->counter = 0;
1207
1208 if (unlikely(vq->inflight->used_idx != vq->used_idx)) {
1209 vq->inflight->desc[vq->inflight->last_batch_head].inflight = 0;
1210
1211 barrier();
1212
1213 vq->inflight->used_idx = vq->used_idx;
1214 }
1215
1216 for (i = 0; i < vq->inflight->desc_num; i++) {
1217 if (vq->inflight->desc[i].inflight == 1) {
1218 vq->inuse++;
1219 }
1220 }
1221
1222 vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
1223
1224 if (vq->inuse) {
1225 vq->resubmit_list = calloc(vq->inuse, sizeof(VuVirtqInflightDesc));
1226 if (!vq->resubmit_list) {
1227 return -1;
1228 }
1229
1230 for (i = 0; i < vq->inflight->desc_num; i++) {
1231 if (vq->inflight->desc[i].inflight) {
1232 vq->resubmit_list[vq->resubmit_num].index = i;
1233 vq->resubmit_list[vq->resubmit_num].counter =
1234 vq->inflight->desc[i].counter;
1235 vq->resubmit_num++;
1236 }
1237 }
1238
1239 if (vq->resubmit_num > 1) {
1240 qsort(vq->resubmit_list, vq->resubmit_num,
1241 sizeof(VuVirtqInflightDesc), inflight_desc_compare);
1242 }
1243 vq->counter = vq->resubmit_list[0].counter + 1;
1244 }
1245
1246 /* in case of I/O hang after reconnecting */
1247 if (eventfd_write(vq->kick_fd, 1)) {
1248 return -1;
1249 }
1250
1251 return 0;
1252 }
1253
1254 static bool
1255 vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
1256 {
1257 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1258 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1259
1260 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1261
1262 if (!vu_check_queue_msg_file(dev, vmsg)) {
1263 return false;
1264 }
1265
1266 if (dev->vq[index].kick_fd != -1) {
1267 dev->remove_watch(dev, dev->vq[index].kick_fd);
1268 close(dev->vq[index].kick_fd);
1269 dev->vq[index].kick_fd = -1;
1270 }
1271
1272 dev->vq[index].kick_fd = nofd ? -1 : vmsg->fds[0];
1273 DPRINT("Got kick_fd: %d for vq: %d\n", dev->vq[index].kick_fd, index);
1274
1275 dev->vq[index].started = true;
1276 if (dev->iface->queue_set_started) {
1277 dev->iface->queue_set_started(dev, index, true);
1278 }
1279
1280 if (dev->vq[index].kick_fd != -1 && dev->vq[index].handler) {
1281 dev->set_watch(dev, dev->vq[index].kick_fd, VU_WATCH_IN,
1282 vu_kick_cb, (void *)(long)index);
1283
1284 DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
1285 dev->vq[index].kick_fd, index);
1286 }
1287
1288 if (vu_check_queue_inflights(dev, &dev->vq[index])) {
1289 vu_panic(dev, "Failed to check inflights for vq: %d\n", index);
1290 }
1291
1292 return false;
1293 }
1294
1295 void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
1296 vu_queue_handler_cb handler)
1297 {
1298 int qidx = vq - dev->vq;
1299
1300 vq->handler = handler;
1301 if (vq->kick_fd >= 0) {
1302 if (handler) {
1303 dev->set_watch(dev, vq->kick_fd, VU_WATCH_IN,
1304 vu_kick_cb, (void *)(long)qidx);
1305 } else {
1306 dev->remove_watch(dev, vq->kick_fd);
1307 }
1308 }
1309 }
1310
1311 bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
1312 int size, int offset)
1313 {
1314 int qidx = vq - dev->vq;
1315 int fd_num = 0;
1316 VhostUserMsg vmsg = {
1317 .request = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
1318 .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1319 .size = sizeof(vmsg.payload.area),
1320 .payload.area = {
1321 .u64 = qidx & VHOST_USER_VRING_IDX_MASK,
1322 .size = size,
1323 .offset = offset,
1324 },
1325 };
1326
1327 if (fd == -1) {
1328 vmsg.payload.area.u64 |= VHOST_USER_VRING_NOFD_MASK;
1329 } else {
1330 vmsg.fds[fd_num++] = fd;
1331 }
1332
1333 vmsg.fd_num = fd_num;
1334
1335 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) {
1336 return false;
1337 }
1338
1339 pthread_mutex_lock(&dev->slave_mutex);
1340 if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {
1341 pthread_mutex_unlock(&dev->slave_mutex);
1342 return false;
1343 }
1344
1345 /* Also unlocks the slave_mutex */
1346 return vu_process_message_reply(dev, &vmsg);
1347 }
1348
1349 static bool
1350 vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
1351 {
1352 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1353 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1354
1355 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1356
1357 if (!vu_check_queue_msg_file(dev, vmsg)) {
1358 return false;
1359 }
1360
1361 if (dev->vq[index].call_fd != -1) {
1362 close(dev->vq[index].call_fd);
1363 dev->vq[index].call_fd = -1;
1364 }
1365
1366 dev->vq[index].call_fd = nofd ? -1 : vmsg->fds[0];
1367
1368 /* in case of I/O hang after reconnecting */
1369 if (dev->vq[index].call_fd != -1 && eventfd_write(vmsg->fds[0], 1)) {
1370 return -1;
1371 }
1372
1373 DPRINT("Got call_fd: %d for vq: %d\n", dev->vq[index].call_fd, index);
1374
1375 return false;
1376 }
1377
1378 static bool
1379 vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg)
1380 {
1381 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1382 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1383
1384 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1385
1386 if (!vu_check_queue_msg_file(dev, vmsg)) {
1387 return false;
1388 }
1389
1390 if (dev->vq[index].err_fd != -1) {
1391 close(dev->vq[index].err_fd);
1392 dev->vq[index].err_fd = -1;
1393 }
1394
1395 dev->vq[index].err_fd = nofd ? -1 : vmsg->fds[0];
1396
1397 return false;
1398 }
1399
1400 static bool
1401 vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
1402 {
1403 /*
1404 * Note that we support, but intentionally do not set,
1405 * VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS. This means that
1406 * a device implementation can return it in its callback
1407 * (get_protocol_features) if it wants to use this for
1408 * simulation, but it is otherwise not desirable (if even
1409 * implemented by the master.)
1410 */
1411 uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_MQ |
1412 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
1413 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ |
1414 1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER |
1415 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD |
1416 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |
1417 1ULL << VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS;
1418
1419 if (have_userfault()) {
1420 features |= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;
1421 }
1422
1423 if (dev->iface->get_config && dev->iface->set_config) {
1424 features |= 1ULL << VHOST_USER_PROTOCOL_F_CONFIG;
1425 }
1426
1427 if (dev->iface->get_protocol_features) {
1428 features |= dev->iface->get_protocol_features(dev);
1429 }
1430
1431 vmsg_set_reply_u64(vmsg, features);
1432 return true;
1433 }
1434
1435 static bool
1436 vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
1437 {
1438 uint64_t features = vmsg->payload.u64;
1439
1440 DPRINT("u64: 0x%016"PRIx64"\n", features);
1441
1442 dev->protocol_features = vmsg->payload.u64;
1443
1444 if (vu_has_protocol_feature(dev,
1445 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
1446 (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_REQ) ||
1447 !vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1448 /*
1449 * The use case for using messages for kick/call is simulation, to make
1450 * the kick and call synchronous. To actually get that behaviour, both
1451 * of the other features are required.
1452 * Theoretically, one could use only kick messages, or do them without
1453 * having F_REPLY_ACK, but too many (possibly pending) messages on the
1454 * socket will eventually cause the master to hang, to avoid this in
1455 * scenarios where not desired enforce that the settings are in a way
1456 * that actually enables the simulation case.
1457 */
1458 vu_panic(dev,
1459 "F_IN_BAND_NOTIFICATIONS requires F_SLAVE_REQ && F_REPLY_ACK");
1460 return false;
1461 }
1462
1463 if (dev->iface->set_protocol_features) {
1464 dev->iface->set_protocol_features(dev, features);
1465 }
1466
1467 return false;
1468 }
1469
1470 static bool
1471 vu_get_queue_num_exec(VuDev *dev, VhostUserMsg *vmsg)
1472 {
1473 vmsg_set_reply_u64(vmsg, dev->max_queues);
1474 return true;
1475 }
1476
1477 static bool
1478 vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
1479 {
1480 unsigned int index = vmsg->payload.state.index;
1481 unsigned int enable = vmsg->payload.state.num;
1482
1483 DPRINT("State.index: %d\n", index);
1484 DPRINT("State.enable: %d\n", enable);
1485
1486 if (index >= dev->max_queues) {
1487 vu_panic(dev, "Invalid vring_enable index: %u", index);
1488 return false;
1489 }
1490
1491 dev->vq[index].enable = enable;
1492 return false;
1493 }
1494
1495 static bool
1496 vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
1497 {
1498 if (vmsg->fd_num != 1) {
1499 vu_panic(dev, "Invalid slave_req_fd message (%d fd's)", vmsg->fd_num);
1500 return false;
1501 }
1502
1503 if (dev->slave_fd != -1) {
1504 close(dev->slave_fd);
1505 }
1506 dev->slave_fd = vmsg->fds[0];
1507 DPRINT("Got slave_fd: %d\n", vmsg->fds[0]);
1508
1509 return false;
1510 }
1511
1512 static bool
1513 vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
1514 {
1515 int ret = -1;
1516
1517 if (dev->iface->get_config) {
1518 ret = dev->iface->get_config(dev, vmsg->payload.config.region,
1519 vmsg->payload.config.size);
1520 }
1521
1522 if (ret) {
1523 /* resize to zero to indicate an error to master */
1524 vmsg->size = 0;
1525 }
1526
1527 return true;
1528 }
1529
1530 static bool
1531 vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
1532 {
1533 int ret = -1;
1534
1535 if (dev->iface->set_config) {
1536 ret = dev->iface->set_config(dev, vmsg->payload.config.region,
1537 vmsg->payload.config.offset,
1538 vmsg->payload.config.size,
1539 vmsg->payload.config.flags);
1540 if (ret) {
1541 vu_panic(dev, "Set virtio configuration space failed");
1542 }
1543 }
1544
1545 return false;
1546 }
1547
1548 static bool
1549 vu_set_postcopy_advise(VuDev *dev, VhostUserMsg *vmsg)
1550 {
1551 dev->postcopy_ufd = -1;
1552 #ifdef UFFDIO_API
1553 struct uffdio_api api_struct;
1554
1555 dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
1556 vmsg->size = 0;
1557 #endif
1558
1559 if (dev->postcopy_ufd == -1) {
1560 vu_panic(dev, "Userfaultfd not available: %s", strerror(errno));
1561 goto out;
1562 }
1563
1564 #ifdef UFFDIO_API
1565 api_struct.api = UFFD_API;
1566 api_struct.features = 0;
1567 if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) {
1568 vu_panic(dev, "Failed UFFDIO_API: %s", strerror(errno));
1569 close(dev->postcopy_ufd);
1570 dev->postcopy_ufd = -1;
1571 goto out;
1572 }
1573 /* TODO: Stash feature flags somewhere */
1574 #endif
1575
1576 out:
1577 /* Return a ufd to the QEMU */
1578 vmsg->fd_num = 1;
1579 vmsg->fds[0] = dev->postcopy_ufd;
1580 return true; /* = send a reply */
1581 }
1582
1583 static bool
1584 vu_set_postcopy_listen(VuDev *dev, VhostUserMsg *vmsg)
1585 {
1586 if (dev->nregions) {
1587 vu_panic(dev, "Regions already registered at postcopy-listen");
1588 vmsg_set_reply_u64(vmsg, -1);
1589 return true;
1590 }
1591 dev->postcopy_listening = true;
1592
1593 vmsg_set_reply_u64(vmsg, 0);
1594 return true;
1595 }
1596
1597 static bool
1598 vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
1599 {
1600 DPRINT("%s: Entry\n", __func__);
1601 dev->postcopy_listening = false;
1602 if (dev->postcopy_ufd > 0) {
1603 close(dev->postcopy_ufd);
1604 dev->postcopy_ufd = -1;
1605 DPRINT("%s: Done close\n", __func__);
1606 }
1607
1608 vmsg_set_reply_u64(vmsg, 0);
1609 DPRINT("%s: exit\n", __func__);
1610 return true;
1611 }
1612
1613 static inline uint64_t
1614 vu_inflight_queue_size(uint16_t queue_size)
1615 {
1616 return ALIGN_UP(sizeof(VuDescStateSplit) * queue_size +
1617 sizeof(uint16_t), INFLIGHT_ALIGNMENT);
1618 }
1619
1620 static bool
1621 vu_get_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
1622 {
1623 int fd;
1624 void *addr;
1625 uint64_t mmap_size;
1626 uint16_t num_queues, queue_size;
1627
1628 if (vmsg->size != sizeof(vmsg->payload.inflight)) {
1629 vu_panic(dev, "Invalid get_inflight_fd message:%d", vmsg->size);
1630 vmsg->payload.inflight.mmap_size = 0;
1631 return true;
1632 }
1633
1634 num_queues = vmsg->payload.inflight.num_queues;
1635 queue_size = vmsg->payload.inflight.queue_size;
1636
1637 DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
1638 DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
1639
1640 mmap_size = vu_inflight_queue_size(queue_size) * num_queues;
1641
1642 addr = qemu_memfd_alloc("vhost-inflight", mmap_size,
1643 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL,
1644 &fd, NULL);
1645
1646 if (!addr) {
1647 vu_panic(dev, "Failed to alloc vhost inflight area");
1648 vmsg->payload.inflight.mmap_size = 0;
1649 return true;
1650 }
1651
1652 memset(addr, 0, mmap_size);
1653
1654 dev->inflight_info.addr = addr;
1655 dev->inflight_info.size = vmsg->payload.inflight.mmap_size = mmap_size;
1656 dev->inflight_info.fd = vmsg->fds[0] = fd;
1657 vmsg->fd_num = 1;
1658 vmsg->payload.inflight.mmap_offset = 0;
1659
1660 DPRINT("send inflight mmap_size: %"PRId64"\n",
1661 vmsg->payload.inflight.mmap_size);
1662 DPRINT("send inflight mmap offset: %"PRId64"\n",
1663 vmsg->payload.inflight.mmap_offset);
1664
1665 return true;
1666 }
1667
1668 static bool
1669 vu_set_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
1670 {
1671 int fd, i;
1672 uint64_t mmap_size, mmap_offset;
1673 uint16_t num_queues, queue_size;
1674 void *rc;
1675
1676 if (vmsg->fd_num != 1 ||
1677 vmsg->size != sizeof(vmsg->payload.inflight)) {
1678 vu_panic(dev, "Invalid set_inflight_fd message size:%d fds:%d",
1679 vmsg->size, vmsg->fd_num);
1680 return false;
1681 }
1682
1683 fd = vmsg->fds[0];
1684 mmap_size = vmsg->payload.inflight.mmap_size;
1685 mmap_offset = vmsg->payload.inflight.mmap_offset;
1686 num_queues = vmsg->payload.inflight.num_queues;
1687 queue_size = vmsg->payload.inflight.queue_size;
1688
1689 DPRINT("set_inflight_fd mmap_size: %"PRId64"\n", mmap_size);
1690 DPRINT("set_inflight_fd mmap_offset: %"PRId64"\n", mmap_offset);
1691 DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
1692 DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
1693
1694 rc = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
1695 fd, mmap_offset);
1696
1697 if (rc == MAP_FAILED) {
1698 vu_panic(dev, "set_inflight_fd mmap error: %s", strerror(errno));
1699 return false;
1700 }
1701
1702 if (dev->inflight_info.fd) {
1703 close(dev->inflight_info.fd);
1704 }
1705
1706 if (dev->inflight_info.addr) {
1707 munmap(dev->inflight_info.addr, dev->inflight_info.size);
1708 }
1709
1710 dev->inflight_info.fd = fd;
1711 dev->inflight_info.addr = rc;
1712 dev->inflight_info.size = mmap_size;
1713
1714 for (i = 0; i < num_queues; i++) {
1715 dev->vq[i].inflight = (VuVirtqInflight *)rc;
1716 dev->vq[i].inflight->desc_num = queue_size;
1717 rc = (void *)((char *)rc + vu_inflight_queue_size(queue_size));
1718 }
1719
1720 return false;
1721 }
1722
1723 static bool
1724 vu_handle_vring_kick(VuDev *dev, VhostUserMsg *vmsg)
1725 {
1726 unsigned int index = vmsg->payload.state.index;
1727
1728 if (index >= dev->max_queues) {
1729 vu_panic(dev, "Invalid queue index: %u", index);
1730 return false;
1731 }
1732
1733 DPRINT("Got kick message: handler:%p idx:%d\n",
1734 dev->vq[index].handler, index);
1735
1736 if (!dev->vq[index].started) {
1737 dev->vq[index].started = true;
1738
1739 if (dev->iface->queue_set_started) {
1740 dev->iface->queue_set_started(dev, index, true);
1741 }
1742 }
1743
1744 if (dev->vq[index].handler) {
1745 dev->vq[index].handler(dev, index);
1746 }
1747
1748 return false;
1749 }
1750
1751 static bool vu_handle_get_max_memslots(VuDev *dev, VhostUserMsg *vmsg)
1752 {
1753 vmsg->flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
1754 vmsg->size = sizeof(vmsg->payload.u64);
1755 vmsg->payload.u64 = VHOST_USER_MAX_RAM_SLOTS;
1756 vmsg->fd_num = 0;
1757
1758 if (!vu_message_write(dev, dev->sock, vmsg)) {
1759 vu_panic(dev, "Failed to send max ram slots: %s\n", strerror(errno));
1760 }
1761
1762 DPRINT("u64: 0x%016"PRIx64"\n", (uint64_t) VHOST_USER_MAX_RAM_SLOTS);
1763
1764 return false;
1765 }
1766
1767 static bool
1768 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
1769 {
1770 int do_reply = 0;
1771
1772 /* Print out generic part of the request. */
1773 DPRINT("================ Vhost user message ================\n");
1774 DPRINT("Request: %s (%d)\n", vu_request_to_string(vmsg->request),
1775 vmsg->request);
1776 DPRINT("Flags: 0x%x\n", vmsg->flags);
1777 DPRINT("Size: %d\n", vmsg->size);
1778
1779 if (vmsg->fd_num) {
1780 int i;
1781 DPRINT("Fds:");
1782 for (i = 0; i < vmsg->fd_num; i++) {
1783 DPRINT(" %d", vmsg->fds[i]);
1784 }
1785 DPRINT("\n");
1786 }
1787
1788 if (dev->iface->process_msg &&
1789 dev->iface->process_msg(dev, vmsg, &do_reply)) {
1790 return do_reply;
1791 }
1792
1793 switch (vmsg->request) {
1794 case VHOST_USER_GET_FEATURES:
1795 return vu_get_features_exec(dev, vmsg);
1796 case VHOST_USER_SET_FEATURES:
1797 return vu_set_features_exec(dev, vmsg);
1798 case VHOST_USER_GET_PROTOCOL_FEATURES:
1799 return vu_get_protocol_features_exec(dev, vmsg);
1800 case VHOST_USER_SET_PROTOCOL_FEATURES:
1801 return vu_set_protocol_features_exec(dev, vmsg);
1802 case VHOST_USER_SET_OWNER:
1803 return vu_set_owner_exec(dev, vmsg);
1804 case VHOST_USER_RESET_OWNER:
1805 return vu_reset_device_exec(dev, vmsg);
1806 case VHOST_USER_SET_MEM_TABLE:
1807 return vu_set_mem_table_exec(dev, vmsg);
1808 case VHOST_USER_SET_LOG_BASE:
1809 return vu_set_log_base_exec(dev, vmsg);
1810 case VHOST_USER_SET_LOG_FD:
1811 return vu_set_log_fd_exec(dev, vmsg);
1812 case VHOST_USER_SET_VRING_NUM:
1813 return vu_set_vring_num_exec(dev, vmsg);
1814 case VHOST_USER_SET_VRING_ADDR:
1815 return vu_set_vring_addr_exec(dev, vmsg);
1816 case VHOST_USER_SET_VRING_BASE:
1817 return vu_set_vring_base_exec(dev, vmsg);
1818 case VHOST_USER_GET_VRING_BASE:
1819 return vu_get_vring_base_exec(dev, vmsg);
1820 case VHOST_USER_SET_VRING_KICK:
1821 return vu_set_vring_kick_exec(dev, vmsg);
1822 case VHOST_USER_SET_VRING_CALL:
1823 return vu_set_vring_call_exec(dev, vmsg);
1824 case VHOST_USER_SET_VRING_ERR:
1825 return vu_set_vring_err_exec(dev, vmsg);
1826 case VHOST_USER_GET_QUEUE_NUM:
1827 return vu_get_queue_num_exec(dev, vmsg);
1828 case VHOST_USER_SET_VRING_ENABLE:
1829 return vu_set_vring_enable_exec(dev, vmsg);
1830 case VHOST_USER_SET_SLAVE_REQ_FD:
1831 return vu_set_slave_req_fd(dev, vmsg);
1832 case VHOST_USER_GET_CONFIG:
1833 return vu_get_config(dev, vmsg);
1834 case VHOST_USER_SET_CONFIG:
1835 return vu_set_config(dev, vmsg);
1836 case VHOST_USER_NONE:
1837 /* if you need processing before exit, override iface->process_msg */
1838 exit(0);
1839 case VHOST_USER_POSTCOPY_ADVISE:
1840 return vu_set_postcopy_advise(dev, vmsg);
1841 case VHOST_USER_POSTCOPY_LISTEN:
1842 return vu_set_postcopy_listen(dev, vmsg);
1843 case VHOST_USER_POSTCOPY_END:
1844 return vu_set_postcopy_end(dev, vmsg);
1845 case VHOST_USER_GET_INFLIGHT_FD:
1846 return vu_get_inflight_fd(dev, vmsg);
1847 case VHOST_USER_SET_INFLIGHT_FD:
1848 return vu_set_inflight_fd(dev, vmsg);
1849 case VHOST_USER_VRING_KICK:
1850 return vu_handle_vring_kick(dev, vmsg);
1851 case VHOST_USER_GET_MAX_MEM_SLOTS:
1852 return vu_handle_get_max_memslots(dev, vmsg);
1853 case VHOST_USER_ADD_MEM_REG:
1854 return vu_add_mem_reg(dev, vmsg);
1855 case VHOST_USER_REM_MEM_REG:
1856 return vu_rem_mem_reg(dev, vmsg);
1857 default:
1858 vmsg_close_fds(vmsg);
1859 vu_panic(dev, "Unhandled request: %d", vmsg->request);
1860 }
1861
1862 return false;
1863 }
1864
1865 bool
1866 vu_dispatch(VuDev *dev)
1867 {
1868 VhostUserMsg vmsg = { 0, };
1869 int reply_requested;
1870 bool need_reply, success = false;
1871
1872 if (!vu_message_read(dev, dev->sock, &vmsg)) {
1873 goto end;
1874 }
1875
1876 need_reply = vmsg.flags & VHOST_USER_NEED_REPLY_MASK;
1877
1878 reply_requested = vu_process_message(dev, &vmsg);
1879 if (!reply_requested && need_reply) {
1880 vmsg_set_reply_u64(&vmsg, 0);
1881 reply_requested = 1;
1882 }
1883
1884 if (!reply_requested) {
1885 success = true;
1886 goto end;
1887 }
1888
1889 if (!vu_send_reply(dev, dev->sock, &vmsg)) {
1890 goto end;
1891 }
1892
1893 success = true;
1894
1895 end:
1896 free(vmsg.data);
1897 return success;
1898 }
1899
1900 void
1901 vu_deinit(VuDev *dev)
1902 {
1903 int i;
1904
1905 for (i = 0; i < dev->nregions; i++) {
1906 VuDevRegion *r = &dev->regions[i];
1907 void *m = (void *) (uintptr_t) r->mmap_addr;
1908 if (m != MAP_FAILED) {
1909 munmap(m, r->size + r->mmap_offset);
1910 }
1911 }
1912 dev->nregions = 0;
1913
1914 for (i = 0; i < dev->max_queues; i++) {
1915 VuVirtq *vq = &dev->vq[i];
1916
1917 if (vq->call_fd != -1) {
1918 close(vq->call_fd);
1919 vq->call_fd = -1;
1920 }
1921
1922 if (vq->kick_fd != -1) {
1923 close(vq->kick_fd);
1924 vq->kick_fd = -1;
1925 }
1926
1927 if (vq->err_fd != -1) {
1928 close(vq->err_fd);
1929 vq->err_fd = -1;
1930 }
1931
1932 if (vq->resubmit_list) {
1933 free(vq->resubmit_list);
1934 vq->resubmit_list = NULL;
1935 }
1936
1937 vq->inflight = NULL;
1938 }
1939
1940 if (dev->inflight_info.addr) {
1941 munmap(dev->inflight_info.addr, dev->inflight_info.size);
1942 dev->inflight_info.addr = NULL;
1943 }
1944
1945 if (dev->inflight_info.fd > 0) {
1946 close(dev->inflight_info.fd);
1947 dev->inflight_info.fd = -1;
1948 }
1949
1950 vu_close_log(dev);
1951 if (dev->slave_fd != -1) {
1952 close(dev->slave_fd);
1953 dev->slave_fd = -1;
1954 }
1955 pthread_mutex_destroy(&dev->slave_mutex);
1956
1957 if (dev->sock != -1) {
1958 close(dev->sock);
1959 }
1960
1961 free(dev->vq);
1962 dev->vq = NULL;
1963 }
1964
1965 bool
1966 vu_init(VuDev *dev,
1967 uint16_t max_queues,
1968 int socket,
1969 vu_panic_cb panic,
1970 vu_set_watch_cb set_watch,
1971 vu_remove_watch_cb remove_watch,
1972 const VuDevIface *iface)
1973 {
1974 uint16_t i;
1975
1976 assert(max_queues > 0);
1977 assert(socket >= 0);
1978 assert(set_watch);
1979 assert(remove_watch);
1980 assert(iface);
1981 assert(panic);
1982
1983 memset(dev, 0, sizeof(*dev));
1984
1985 dev->sock = socket;
1986 dev->panic = panic;
1987 dev->set_watch = set_watch;
1988 dev->remove_watch = remove_watch;
1989 dev->iface = iface;
1990 dev->log_call_fd = -1;
1991 pthread_mutex_init(&dev->slave_mutex, NULL);
1992 dev->slave_fd = -1;
1993 dev->max_queues = max_queues;
1994
1995 dev->vq = malloc(max_queues * sizeof(dev->vq[0]));
1996 if (!dev->vq) {
1997 DPRINT("%s: failed to malloc virtqueues\n", __func__);
1998 return false;
1999 }
2000
2001 for (i = 0; i < max_queues; i++) {
2002 dev->vq[i] = (VuVirtq) {
2003 .call_fd = -1, .kick_fd = -1, .err_fd = -1,
2004 .notification = true,
2005 };
2006 }
2007
2008 return true;
2009 }
2010
2011 VuVirtq *
2012 vu_get_queue(VuDev *dev, int qidx)
2013 {
2014 assert(qidx < dev->max_queues);
2015 return &dev->vq[qidx];
2016 }
2017
2018 bool
2019 vu_queue_enabled(VuDev *dev, VuVirtq *vq)
2020 {
2021 return vq->enable;
2022 }
2023
2024 bool
2025 vu_queue_started(const VuDev *dev, const VuVirtq *vq)
2026 {
2027 return vq->started;
2028 }
2029
2030 static inline uint16_t
2031 vring_avail_flags(VuVirtq *vq)
2032 {
2033 return lduw_le_p(&vq->vring.avail->flags);
2034 }
2035
2036 static inline uint16_t
2037 vring_avail_idx(VuVirtq *vq)
2038 {
2039 vq->shadow_avail_idx = lduw_le_p(&vq->vring.avail->idx);
2040
2041 return vq->shadow_avail_idx;
2042 }
2043
2044 static inline uint16_t
2045 vring_avail_ring(VuVirtq *vq, int i)
2046 {
2047 return lduw_le_p(&vq->vring.avail->ring[i]);
2048 }
2049
2050 static inline uint16_t
2051 vring_get_used_event(VuVirtq *vq)
2052 {
2053 return vring_avail_ring(vq, vq->vring.num);
2054 }
2055
2056 static int
2057 virtqueue_num_heads(VuDev *dev, VuVirtq *vq, unsigned int idx)
2058 {
2059 uint16_t num_heads = vring_avail_idx(vq) - idx;
2060
2061 /* Check it isn't doing very strange things with descriptor numbers. */
2062 if (num_heads > vq->vring.num) {
2063 vu_panic(dev, "Guest moved used index from %u to %u",
2064 idx, vq->shadow_avail_idx);
2065 return -1;
2066 }
2067 if (num_heads) {
2068 /* On success, callers read a descriptor at vq->last_avail_idx.
2069 * Make sure descriptor read does not bypass avail index read. */
2070 smp_rmb();
2071 }
2072
2073 return num_heads;
2074 }
2075
2076 static bool
2077 virtqueue_get_head(VuDev *dev, VuVirtq *vq,
2078 unsigned int idx, unsigned int *head)
2079 {
2080 /* Grab the next descriptor number they're advertising, and increment
2081 * the index we've seen. */
2082 *head = vring_avail_ring(vq, idx % vq->vring.num);
2083
2084 /* If their number is silly, that's a fatal mistake. */
2085 if (*head >= vq->vring.num) {
2086 vu_panic(dev, "Guest says index %u is available", *head);
2087 return false;
2088 }
2089
2090 return true;
2091 }
2092
2093 static int
2094 virtqueue_read_indirect_desc(VuDev *dev, struct vring_desc *desc,
2095 uint64_t addr, size_t len)
2096 {
2097 struct vring_desc *ori_desc;
2098 uint64_t read_len;
2099
2100 if (len > (VIRTQUEUE_MAX_SIZE * sizeof(struct vring_desc))) {
2101 return -1;
2102 }
2103
2104 if (len == 0) {
2105 return -1;
2106 }
2107
2108 while (len) {
2109 read_len = len;
2110 ori_desc = vu_gpa_to_va(dev, &read_len, addr);
2111 if (!ori_desc) {
2112 return -1;
2113 }
2114
2115 memcpy(desc, ori_desc, read_len);
2116 len -= read_len;
2117 addr += read_len;
2118 desc += read_len;
2119 }
2120
2121 return 0;
2122 }
2123
2124 enum {
2125 VIRTQUEUE_READ_DESC_ERROR = -1,
2126 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */
2127 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
2128 };
2129
2130 static int
2131 virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc,
2132 int i, unsigned int max, unsigned int *next)
2133 {
2134 /* If this descriptor says it doesn't chain, we're done. */
2135 if (!(lduw_le_p(&desc[i].flags) & VRING_DESC_F_NEXT)) {
2136 return VIRTQUEUE_READ_DESC_DONE;
2137 }
2138
2139 /* Check they're not leading us off end of descriptors. */
2140 *next = lduw_le_p(&desc[i].next);
2141 /* Make sure compiler knows to grab that: we don't want it changing! */
2142 smp_wmb();
2143
2144 if (*next >= max) {
2145 vu_panic(dev, "Desc next is %u", *next);
2146 return VIRTQUEUE_READ_DESC_ERROR;
2147 }
2148
2149 return VIRTQUEUE_READ_DESC_MORE;
2150 }
2151
2152 void
2153 vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes,
2154 unsigned int *out_bytes,
2155 unsigned max_in_bytes, unsigned max_out_bytes)
2156 {
2157 unsigned int idx;
2158 unsigned int total_bufs, in_total, out_total;
2159 int rc;
2160
2161 idx = vq->last_avail_idx;
2162
2163 total_bufs = in_total = out_total = 0;
2164 if (unlikely(dev->broken) ||
2165 unlikely(!vq->vring.avail)) {
2166 goto done;
2167 }
2168
2169 while ((rc = virtqueue_num_heads(dev, vq, idx)) > 0) {
2170 unsigned int max, desc_len, num_bufs, indirect = 0;
2171 uint64_t desc_addr, read_len;
2172 struct vring_desc *desc;
2173 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2174 unsigned int i;
2175
2176 max = vq->vring.num;
2177 num_bufs = total_bufs;
2178 if (!virtqueue_get_head(dev, vq, idx++, &i)) {
2179 goto err;
2180 }
2181 desc = vq->vring.desc;
2182
2183 if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) {
2184 if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) {
2185 vu_panic(dev, "Invalid size for indirect buffer table");
2186 goto err;
2187 }
2188
2189 /* If we've got too many, that implies a descriptor loop. */
2190 if (num_bufs >= max) {
2191 vu_panic(dev, "Looped descriptor");
2192 goto err;
2193 }
2194
2195 /* loop over the indirect descriptor table */
2196 indirect = 1;
2197 desc_addr = ldq_le_p(&desc[i].addr);
2198 desc_len = ldl_le_p(&desc[i].len);
2199 max = desc_len / sizeof(struct vring_desc);
2200 read_len = desc_len;
2201 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2202 if (unlikely(desc && read_len != desc_len)) {
2203 /* Failed to use zero copy */
2204 desc = NULL;
2205 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2206 desc_addr,
2207 desc_len)) {
2208 desc = desc_buf;
2209 }
2210 }
2211 if (!desc) {
2212 vu_panic(dev, "Invalid indirect buffer table");
2213 goto err;
2214 }
2215 num_bufs = i = 0;
2216 }
2217
2218 do {
2219 /* If we've got too many, that implies a descriptor loop. */
2220 if (++num_bufs > max) {
2221 vu_panic(dev, "Looped descriptor");
2222 goto err;
2223 }
2224
2225 if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) {
2226 in_total += ldl_le_p(&desc[i].len);
2227 } else {
2228 out_total += ldl_le_p(&desc[i].len);
2229 }
2230 if (in_total >= max_in_bytes && out_total >= max_out_bytes) {
2231 goto done;
2232 }
2233 rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
2234 } while (rc == VIRTQUEUE_READ_DESC_MORE);
2235
2236 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
2237 goto err;
2238 }
2239
2240 if (!indirect) {
2241 total_bufs = num_bufs;
2242 } else {
2243 total_bufs++;
2244 }
2245 }
2246 if (rc < 0) {
2247 goto err;
2248 }
2249 done:
2250 if (in_bytes) {
2251 *in_bytes = in_total;
2252 }
2253 if (out_bytes) {
2254 *out_bytes = out_total;
2255 }
2256 return;
2257
2258 err:
2259 in_total = out_total = 0;
2260 goto done;
2261 }
2262
2263 bool
2264 vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes,
2265 unsigned int out_bytes)
2266 {
2267 unsigned int in_total, out_total;
2268
2269 vu_queue_get_avail_bytes(dev, vq, &in_total, &out_total,
2270 in_bytes, out_bytes);
2271
2272 return in_bytes <= in_total && out_bytes <= out_total;
2273 }
2274
2275 /* Fetch avail_idx from VQ memory only when we really need to know if
2276 * guest has added some buffers. */
2277 bool
2278 vu_queue_empty(VuDev *dev, VuVirtq *vq)
2279 {
2280 if (unlikely(dev->broken) ||
2281 unlikely(!vq->vring.avail)) {
2282 return true;
2283 }
2284
2285 if (vq->shadow_avail_idx != vq->last_avail_idx) {
2286 return false;
2287 }
2288
2289 return vring_avail_idx(vq) == vq->last_avail_idx;
2290 }
2291
2292 static bool
2293 vring_notify(VuDev *dev, VuVirtq *vq)
2294 {
2295 uint16_t old, new;
2296 bool v;
2297
2298 /* We need to expose used array entries before checking used event. */
2299 smp_mb();
2300
2301 /* Always notify when queue is empty (when feature acknowledge) */
2302 if (vu_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
2303 !vq->inuse && vu_queue_empty(dev, vq)) {
2304 return true;
2305 }
2306
2307 if (!vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2308 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
2309 }
2310
2311 v = vq->signalled_used_valid;
2312 vq->signalled_used_valid = true;
2313 old = vq->signalled_used;
2314 new = vq->signalled_used = vq->used_idx;
2315 return !v || vring_need_event(vring_get_used_event(vq), new, old);
2316 }
2317
2318 static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
2319 {
2320 if (unlikely(dev->broken) ||
2321 unlikely(!vq->vring.avail)) {
2322 return;
2323 }
2324
2325 if (!vring_notify(dev, vq)) {
2326 DPRINT("skipped notify...\n");
2327 return;
2328 }
2329
2330 if (vq->call_fd < 0 &&
2331 vu_has_protocol_feature(dev,
2332 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
2333 vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
2334 VhostUserMsg vmsg = {
2335 .request = VHOST_USER_SLAVE_VRING_CALL,
2336 .flags = VHOST_USER_VERSION,
2337 .size = sizeof(vmsg.payload.state),
2338 .payload.state = {
2339 .index = vq - dev->vq,
2340 },
2341 };
2342 bool ack = sync &&
2343 vu_has_protocol_feature(dev,
2344 VHOST_USER_PROTOCOL_F_REPLY_ACK);
2345
2346 if (ack) {
2347 vmsg.flags |= VHOST_USER_NEED_REPLY_MASK;
2348 }
2349
2350 vu_message_write(dev, dev->slave_fd, &vmsg);
2351 if (ack) {
2352 vu_message_read(dev, dev->slave_fd, &vmsg);
2353 }
2354 return;
2355 }
2356
2357 if (eventfd_write(vq->call_fd, 1) < 0) {
2358 vu_panic(dev, "Error writing eventfd: %s", strerror(errno));
2359 }
2360 }
2361
2362 void vu_queue_notify(VuDev *dev, VuVirtq *vq)
2363 {
2364 _vu_queue_notify(dev, vq, false);
2365 }
2366
2367 void vu_queue_notify_sync(VuDev *dev, VuVirtq *vq)
2368 {
2369 _vu_queue_notify(dev, vq, true);
2370 }
2371
2372 static inline void
2373 vring_used_flags_set_bit(VuVirtq *vq, int mask)
2374 {
2375 uint16_t *flags;
2376
2377 flags = (uint16_t *)((char*)vq->vring.used +
2378 offsetof(struct vring_used, flags));
2379 stw_le_p(flags, lduw_le_p(flags) | mask);
2380 }
2381
2382 static inline void
2383 vring_used_flags_unset_bit(VuVirtq *vq, int mask)
2384 {
2385 uint16_t *flags;
2386
2387 flags = (uint16_t *)((char*)vq->vring.used +
2388 offsetof(struct vring_used, flags));
2389 stw_le_p(flags, lduw_le_p(flags) & ~mask);
2390 }
2391
2392 static inline void
2393 vring_set_avail_event(VuVirtq *vq, uint16_t val)
2394 {
2395 if (!vq->notification) {
2396 return;
2397 }
2398
2399 stw_le_p(&vq->vring.used->ring[vq->vring.num], val);
2400 }
2401
2402 void
2403 vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int enable)
2404 {
2405 vq->notification = enable;
2406 if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2407 vring_set_avail_event(vq, vring_avail_idx(vq));
2408 } else if (enable) {
2409 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
2410 } else {
2411 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
2412 }
2413 if (enable) {
2414 /* Expose avail event/used flags before caller checks the avail idx. */
2415 smp_mb();
2416 }
2417 }
2418
2419 static bool
2420 virtqueue_map_desc(VuDev *dev,
2421 unsigned int *p_num_sg, struct iovec *iov,
2422 unsigned int max_num_sg, bool is_write,
2423 uint64_t pa, size_t sz)
2424 {
2425 unsigned num_sg = *p_num_sg;
2426
2427 assert(num_sg <= max_num_sg);
2428
2429 if (!sz) {
2430 vu_panic(dev, "virtio: zero sized buffers are not allowed");
2431 return false;
2432 }
2433
2434 while (sz) {
2435 uint64_t len = sz;
2436
2437 if (num_sg == max_num_sg) {
2438 vu_panic(dev, "virtio: too many descriptors in indirect table");
2439 return false;
2440 }
2441
2442 iov[num_sg].iov_base = vu_gpa_to_va(dev, &len, pa);
2443 if (iov[num_sg].iov_base == NULL) {
2444 vu_panic(dev, "virtio: invalid address for buffers");
2445 return false;
2446 }
2447 iov[num_sg].iov_len = len;
2448 num_sg++;
2449 sz -= len;
2450 pa += len;
2451 }
2452
2453 *p_num_sg = num_sg;
2454 return true;
2455 }
2456
2457 static void *
2458 virtqueue_alloc_element(size_t sz,
2459 unsigned out_num, unsigned in_num)
2460 {
2461 VuVirtqElement *elem;
2462 size_t in_sg_ofs = ALIGN_UP(sz, __alignof__(elem->in_sg[0]));
2463 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]);
2464 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]);
2465
2466 assert(sz >= sizeof(VuVirtqElement));
2467 elem = malloc(out_sg_end);
2468 elem->out_num = out_num;
2469 elem->in_num = in_num;
2470 elem->in_sg = (void *)elem + in_sg_ofs;
2471 elem->out_sg = (void *)elem + out_sg_ofs;
2472 return elem;
2473 }
2474
2475 static void *
2476 vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz)
2477 {
2478 struct vring_desc *desc = vq->vring.desc;
2479 uint64_t desc_addr, read_len;
2480 unsigned int desc_len;
2481 unsigned int max = vq->vring.num;
2482 unsigned int i = idx;
2483 VuVirtqElement *elem;
2484 unsigned int out_num = 0, in_num = 0;
2485 struct iovec iov[VIRTQUEUE_MAX_SIZE];
2486 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2487 int rc;
2488
2489 if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) {
2490 if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) {
2491 vu_panic(dev, "Invalid size for indirect buffer table");
2492 return NULL;
2493 }
2494
2495 /* loop over the indirect descriptor table */
2496 desc_addr = ldq_le_p(&desc[i].addr);
2497 desc_len = ldl_le_p(&desc[i].len);
2498 max = desc_len / sizeof(struct vring_desc);
2499 read_len = desc_len;
2500 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2501 if (unlikely(desc && read_len != desc_len)) {
2502 /* Failed to use zero copy */
2503 desc = NULL;
2504 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2505 desc_addr,
2506 desc_len)) {
2507 desc = desc_buf;
2508 }
2509 }
2510 if (!desc) {
2511 vu_panic(dev, "Invalid indirect buffer table");
2512 return NULL;
2513 }
2514 i = 0;
2515 }
2516
2517 /* Collect all the descriptors */
2518 do {
2519 if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) {
2520 if (!virtqueue_map_desc(dev, &in_num, iov + out_num,
2521 VIRTQUEUE_MAX_SIZE - out_num, true,
2522 ldq_le_p(&desc[i].addr),
2523 ldl_le_p(&desc[i].len))) {
2524 return NULL;
2525 }
2526 } else {
2527 if (in_num) {
2528 vu_panic(dev, "Incorrect order for descriptors");
2529 return NULL;
2530 }
2531 if (!virtqueue_map_desc(dev, &out_num, iov,
2532 VIRTQUEUE_MAX_SIZE, false,
2533 ldq_le_p(&desc[i].addr),
2534 ldl_le_p(&desc[i].len))) {
2535 return NULL;
2536 }
2537 }
2538
2539 /* If we've got too many, that implies a descriptor loop. */
2540 if ((in_num + out_num) > max) {
2541 vu_panic(dev, "Looped descriptor");
2542 return NULL;
2543 }
2544 rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
2545 } while (rc == VIRTQUEUE_READ_DESC_MORE);
2546
2547 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
2548 vu_panic(dev, "read descriptor error");
2549 return NULL;
2550 }
2551
2552 /* Now copy what we have collected and mapped */
2553 elem = virtqueue_alloc_element(sz, out_num, in_num);
2554 elem->index = idx;
2555 for (i = 0; i < out_num; i++) {
2556 elem->out_sg[i] = iov[i];
2557 }
2558 for (i = 0; i < in_num; i++) {
2559 elem->in_sg[i] = iov[out_num + i];
2560 }
2561
2562 return elem;
2563 }
2564
2565 static int
2566 vu_queue_inflight_get(VuDev *dev, VuVirtq *vq, int desc_idx)
2567 {
2568 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2569 return 0;
2570 }
2571
2572 if (unlikely(!vq->inflight)) {
2573 return -1;
2574 }
2575
2576 vq->inflight->desc[desc_idx].counter = vq->counter++;
2577 vq->inflight->desc[desc_idx].inflight = 1;
2578
2579 return 0;
2580 }
2581
2582 static int
2583 vu_queue_inflight_pre_put(VuDev *dev, VuVirtq *vq, int desc_idx)
2584 {
2585 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2586 return 0;
2587 }
2588
2589 if (unlikely(!vq->inflight)) {
2590 return -1;
2591 }
2592
2593 vq->inflight->last_batch_head = desc_idx;
2594
2595 return 0;
2596 }
2597
2598 static int
2599 vu_queue_inflight_post_put(VuDev *dev, VuVirtq *vq, int desc_idx)
2600 {
2601 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2602 return 0;
2603 }
2604
2605 if (unlikely(!vq->inflight)) {
2606 return -1;
2607 }
2608
2609 barrier();
2610
2611 vq->inflight->desc[desc_idx].inflight = 0;
2612
2613 barrier();
2614
2615 vq->inflight->used_idx = vq->used_idx;
2616
2617 return 0;
2618 }
2619
2620 void *
2621 vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
2622 {
2623 int i;
2624 unsigned int head;
2625 VuVirtqElement *elem;
2626
2627 if (unlikely(dev->broken) ||
2628 unlikely(!vq->vring.avail)) {
2629 return NULL;
2630 }
2631
2632 if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
2633 i = (--vq->resubmit_num);
2634 elem = vu_queue_map_desc(dev, vq, vq->resubmit_list[i].index, sz);
2635
2636 if (!vq->resubmit_num) {
2637 free(vq->resubmit_list);
2638 vq->resubmit_list = NULL;
2639 }
2640
2641 return elem;
2642 }
2643
2644 if (vu_queue_empty(dev, vq)) {
2645 return NULL;
2646 }
2647 /*
2648 * Needed after virtio_queue_empty(), see comment in
2649 * virtqueue_num_heads().
2650 */
2651 smp_rmb();
2652
2653 if (vq->inuse >= vq->vring.num) {
2654 vu_panic(dev, "Virtqueue size exceeded");
2655 return NULL;
2656 }
2657
2658 if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
2659 return NULL;
2660 }
2661
2662 if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2663 vring_set_avail_event(vq, vq->last_avail_idx);
2664 }
2665
2666 elem = vu_queue_map_desc(dev, vq, head, sz);
2667
2668 if (!elem) {
2669 return NULL;
2670 }
2671
2672 vq->inuse++;
2673
2674 vu_queue_inflight_get(dev, vq, head);
2675
2676 return elem;
2677 }
2678
2679 static void
2680 vu_queue_detach_element(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
2681 size_t len)
2682 {
2683 vq->inuse--;
2684 /* unmap, when DMA support is added */
2685 }
2686
2687 void
2688 vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
2689 size_t len)
2690 {
2691 vq->last_avail_idx--;
2692 vu_queue_detach_element(dev, vq, elem, len);
2693 }
2694
2695 bool
2696 vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num)
2697 {
2698 if (num > vq->inuse) {
2699 return false;
2700 }
2701 vq->last_avail_idx -= num;
2702 vq->inuse -= num;
2703 return true;
2704 }
2705
2706 static inline
2707 void vring_used_write(VuDev *dev, VuVirtq *vq,
2708 struct vring_used_elem *uelem, int i)
2709 {
2710 struct vring_used *used = vq->vring.used;
2711
2712 used->ring[i] = *uelem;
2713 vu_log_write(dev, vq->vring.log_guest_addr +
2714 offsetof(struct vring_used, ring[i]),
2715 sizeof(used->ring[i]));
2716 }
2717
2718
2719 static void
2720 vu_log_queue_fill(VuDev *dev, VuVirtq *vq,
2721 const VuVirtqElement *elem,
2722 unsigned int len)
2723 {
2724 struct vring_desc *desc = vq->vring.desc;
2725 unsigned int i, max, min, desc_len;
2726 uint64_t desc_addr, read_len;
2727 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2728 unsigned num_bufs = 0;
2729
2730 max = vq->vring.num;
2731 i = elem->index;
2732
2733 if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) {
2734 if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) {
2735 vu_panic(dev, "Invalid size for indirect buffer table");
2736 }
2737
2738 /* loop over the indirect descriptor table */
2739 desc_addr = ldq_le_p(&desc[i].addr);
2740 desc_len = ldl_le_p(&desc[i].len);
2741 max = desc_len / sizeof(struct vring_desc);
2742 read_len = desc_len;
2743 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2744 if (unlikely(desc && read_len != desc_len)) {
2745 /* Failed to use zero copy */
2746 desc = NULL;
2747 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2748 desc_addr,
2749 desc_len)) {
2750 desc = desc_buf;
2751 }
2752 }
2753 if (!desc) {
2754 vu_panic(dev, "Invalid indirect buffer table");
2755 return;
2756 }
2757 i = 0;
2758 }
2759
2760 do {
2761 if (++num_bufs > max) {
2762 vu_panic(dev, "Looped descriptor");
2763 return;
2764 }
2765
2766 if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) {
2767 min = MIN(ldl_le_p(&desc[i].len), len);
2768 vu_log_write(dev, ldq_le_p(&desc[i].addr), min);
2769 len -= min;
2770 }
2771
2772 } while (len > 0 &&
2773 (virtqueue_read_next_desc(dev, desc, i, max, &i)
2774 == VIRTQUEUE_READ_DESC_MORE));
2775 }
2776
2777 void
2778 vu_queue_fill(VuDev *dev, VuVirtq *vq,
2779 const VuVirtqElement *elem,
2780 unsigned int len, unsigned int idx)
2781 {
2782 struct vring_used_elem uelem;
2783
2784 if (unlikely(dev->broken) ||
2785 unlikely(!vq->vring.avail)) {
2786 return;
2787 }
2788
2789 vu_log_queue_fill(dev, vq, elem, len);
2790
2791 idx = (idx + vq->used_idx) % vq->vring.num;
2792
2793 stl_le_p(&uelem.id, elem->index);
2794 stl_le_p(&uelem.len, len);
2795 vring_used_write(dev, vq, &uelem, idx);
2796 }
2797
2798 static inline
2799 void vring_used_idx_set(VuDev *dev, VuVirtq *vq, uint16_t val)
2800 {
2801 stw_le_p(&vq->vring.used->idx, val);
2802 vu_log_write(dev,
2803 vq->vring.log_guest_addr + offsetof(struct vring_used, idx),
2804 sizeof(vq->vring.used->idx));
2805
2806 vq->used_idx = val;
2807 }
2808
2809 void
2810 vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int count)
2811 {
2812 uint16_t old, new;
2813
2814 if (unlikely(dev->broken) ||
2815 unlikely(!vq->vring.avail)) {
2816 return;
2817 }
2818
2819 /* Make sure buffer is written before we update index. */
2820 smp_wmb();
2821
2822 old = vq->used_idx;
2823 new = old + count;
2824 vring_used_idx_set(dev, vq, new);
2825 vq->inuse -= count;
2826 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) {
2827 vq->signalled_used_valid = false;
2828 }
2829 }
2830
2831 void
2832 vu_queue_push(VuDev *dev, VuVirtq *vq,
2833 const VuVirtqElement *elem, unsigned int len)
2834 {
2835 vu_queue_fill(dev, vq, elem, len, 0);
2836 vu_queue_inflight_pre_put(dev, vq, elem->index);
2837 vu_queue_flush(dev, vq, 1);
2838 vu_queue_inflight_post_put(dev, vq, elem->index);
2839 }
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