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libvhost-user: make it a meson subproject
[qemu/kevin.git] / subprojects / libvhost-user / libvhost-user.c
blobfab7ca17ee1fb27bcfc338527d1aeb9f923aade5
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 <endian.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
45 #include "libvhost-user.h"
46
47 /* usually provided by GLib */
48 #ifndef MIN
49 #define MIN(x, y) ({ \
50 typeof(x) _min1 = (x); \
51 typeof(y) _min2 = (y); \
52 (void) (&_min1 == &_min2); \
53 _min1 < _min2 ? _min1 : _min2; })
54 #endif
55
56 /* Round number down to multiple */
57 #define ALIGN_DOWN(n, m) ((n) / (m) * (m))
58
59 /* Round number up to multiple */
60 #define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
61
62 #ifndef unlikely
63 #define unlikely(x) __builtin_expect(!!(x), 0)
64 #endif
65
66 /* Align each region to cache line size in inflight buffer */
67 #define INFLIGHT_ALIGNMENT 64
68
69 /* The version of inflight buffer */
70 #define INFLIGHT_VERSION 1
71
72 /* The version of the protocol we support */
73 #define VHOST_USER_VERSION 1
74 #define LIBVHOST_USER_DEBUG 0
75
76 #define DPRINT(...) \
77 do { \
78 if (LIBVHOST_USER_DEBUG) { \
79 fprintf(stderr, __VA_ARGS__); \
80 } \
81 } while (0)
82
83 static inline
84 bool has_feature(uint64_t features, unsigned int fbit)
85 {
86 assert(fbit < 64);
87 return !!(features & (1ULL << fbit));
88 }
89
90 static inline
91 bool vu_has_feature(VuDev *dev,
92 unsigned int fbit)
93 {
94 return has_feature(dev->features, fbit);
95 }
96
97 static inline bool vu_has_protocol_feature(VuDev *dev, unsigned int fbit)
98 {
99 return has_feature(dev->protocol_features, fbit);
100 }
101
102 static const char *
103 vu_request_to_string(unsigned int req)
104 {
105 #define REQ(req) [req] = #req
106 static const char *vu_request_str[] = {
107 REQ(VHOST_USER_NONE),
108 REQ(VHOST_USER_GET_FEATURES),
109 REQ(VHOST_USER_SET_FEATURES),
110 REQ(VHOST_USER_SET_OWNER),
111 REQ(VHOST_USER_RESET_OWNER),
112 REQ(VHOST_USER_SET_MEM_TABLE),
113 REQ(VHOST_USER_SET_LOG_BASE),
114 REQ(VHOST_USER_SET_LOG_FD),
115 REQ(VHOST_USER_SET_VRING_NUM),
116 REQ(VHOST_USER_SET_VRING_ADDR),
117 REQ(VHOST_USER_SET_VRING_BASE),
118 REQ(VHOST_USER_GET_VRING_BASE),
119 REQ(VHOST_USER_SET_VRING_KICK),
120 REQ(VHOST_USER_SET_VRING_CALL),
121 REQ(VHOST_USER_SET_VRING_ERR),
122 REQ(VHOST_USER_GET_PROTOCOL_FEATURES),
123 REQ(VHOST_USER_SET_PROTOCOL_FEATURES),
124 REQ(VHOST_USER_GET_QUEUE_NUM),
125 REQ(VHOST_USER_SET_VRING_ENABLE),
126 REQ(VHOST_USER_SEND_RARP),
127 REQ(VHOST_USER_NET_SET_MTU),
128 REQ(VHOST_USER_SET_SLAVE_REQ_FD),
129 REQ(VHOST_USER_IOTLB_MSG),
130 REQ(VHOST_USER_SET_VRING_ENDIAN),
131 REQ(VHOST_USER_GET_CONFIG),
132 REQ(VHOST_USER_SET_CONFIG),
133 REQ(VHOST_USER_POSTCOPY_ADVISE),
134 REQ(VHOST_USER_POSTCOPY_LISTEN),
135 REQ(VHOST_USER_POSTCOPY_END),
136 REQ(VHOST_USER_GET_INFLIGHT_FD),
137 REQ(VHOST_USER_SET_INFLIGHT_FD),
138 REQ(VHOST_USER_GPU_SET_SOCKET),
139 REQ(VHOST_USER_VRING_KICK),
140 REQ(VHOST_USER_GET_MAX_MEM_SLOTS),
141 REQ(VHOST_USER_ADD_MEM_REG),
142 REQ(VHOST_USER_REM_MEM_REG),
143 REQ(VHOST_USER_MAX),
144 };
145 #undef REQ
146
147 if (req < VHOST_USER_MAX) {
148 return vu_request_str[req];
149 } else {
150 return "unknown";
151 }
152 }
153
154 static void
155 vu_panic(VuDev *dev, const char *msg, ...)
156 {
157 char *buf = NULL;
158 va_list ap;
159
160 va_start(ap, msg);
161 if (vasprintf(&buf, msg, ap) < 0) {
162 buf = NULL;
163 }
164 va_end(ap);
165
166 dev->broken = true;
167 dev->panic(dev, buf);
168 free(buf);
169
170 /*
171 * FIXME:
172 * find a way to call virtio_error, or perhaps close the connection?
173 */
174 }
175
176 /* Translate guest physical address to our virtual address. */
177 void *
178 vu_gpa_to_va(VuDev *dev, uint64_t *plen, uint64_t guest_addr)
179 {
180 int i;
181
182 if (*plen == 0) {
183 return NULL;
184 }
185
186 /* Find matching memory region. */
187 for (i = 0; i < dev->nregions; i++) {
188 VuDevRegion *r = &dev->regions[i];
189
190 if ((guest_addr >= r->gpa) && (guest_addr < (r->gpa + r->size))) {
191 if ((guest_addr + *plen) > (r->gpa + r->size)) {
192 *plen = r->gpa + r->size - guest_addr;
193 }
194 return (void *)(uintptr_t)
195 guest_addr - r->gpa + r->mmap_addr + r->mmap_offset;
196 }
197 }
198
199 return NULL;
200 }
201
202 /* Translate qemu virtual address to our virtual address. */
203 static void *
204 qva_to_va(VuDev *dev, uint64_t qemu_addr)
205 {
206 int i;
207
208 /* Find matching memory region. */
209 for (i = 0; i < dev->nregions; i++) {
210 VuDevRegion *r = &dev->regions[i];
211
212 if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
213 return (void *)(uintptr_t)
214 qemu_addr - r->qva + r->mmap_addr + r->mmap_offset;
215 }
216 }
217
218 return NULL;
219 }
220
221 static void
222 vmsg_close_fds(VhostUserMsg *vmsg)
223 {
224 int i;
225
226 for (i = 0; i < vmsg->fd_num; i++) {
227 close(vmsg->fds[i]);
228 }
229 }
230
231 /* Set reply payload.u64 and clear request flags and fd_num */
232 static void vmsg_set_reply_u64(VhostUserMsg *vmsg, uint64_t val)
233 {
234 vmsg->flags = 0; /* defaults will be set by vu_send_reply() */
235 vmsg->size = sizeof(vmsg->payload.u64);
236 vmsg->payload.u64 = val;
237 vmsg->fd_num = 0;
238 }
239
240 /* A test to see if we have userfault available */
241 static bool
242 have_userfault(void)
243 {
244 #if defined(__linux__) && defined(__NR_userfaultfd) &&\
245 defined(UFFD_FEATURE_MISSING_SHMEM) &&\
246 defined(UFFD_FEATURE_MISSING_HUGETLBFS)
247 /* Now test the kernel we're running on really has the features */
248 int ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
249 struct uffdio_api api_struct;
250 if (ufd < 0) {
251 return false;
252 }
253
254 api_struct.api = UFFD_API;
255 api_struct.features = UFFD_FEATURE_MISSING_SHMEM |
256 UFFD_FEATURE_MISSING_HUGETLBFS;
257 if (ioctl(ufd, UFFDIO_API, &api_struct)) {
258 close(ufd);
259 return false;
260 }
261 close(ufd);
262 return true;
263
264 #else
265 return false;
266 #endif
267 }
268
269 static bool
270 vu_message_read_default(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
271 {
272 char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
273 struct iovec iov = {
274 .iov_base = (char *)vmsg,
275 .iov_len = VHOST_USER_HDR_SIZE,
276 };
277 struct msghdr msg = {
278 .msg_iov = &iov,
279 .msg_iovlen = 1,
280 .msg_control = control,
281 .msg_controllen = sizeof(control),
282 };
283 size_t fd_size;
284 struct cmsghdr *cmsg;
285 int rc;
286
287 do {
288 rc = recvmsg(conn_fd, &msg, 0);
289 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
290
291 if (rc < 0) {
292 vu_panic(dev, "Error while recvmsg: %s", strerror(errno));
293 return false;
294 }
295
296 vmsg->fd_num = 0;
297 for (cmsg = CMSG_FIRSTHDR(&msg);
298 cmsg != NULL;
299 cmsg = CMSG_NXTHDR(&msg, cmsg))
300 {
301 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
302 fd_size = cmsg->cmsg_len - CMSG_LEN(0);
303 vmsg->fd_num = fd_size / sizeof(int);
304 memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
305 break;
306 }
307 }
308
309 if (vmsg->size > sizeof(vmsg->payload)) {
310 vu_panic(dev,
311 "Error: too big message request: %d, size: vmsg->size: %u, "
312 "while sizeof(vmsg->payload) = %zu\n",
313 vmsg->request, vmsg->size, sizeof(vmsg->payload));
314 goto fail;
315 }
316
317 if (vmsg->size) {
318 do {
319 rc = read(conn_fd, &vmsg->payload, vmsg->size);
320 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
321
322 if (rc <= 0) {
323 vu_panic(dev, "Error while reading: %s", strerror(errno));
324 goto fail;
325 }
326
327 assert(rc == vmsg->size);
328 }
329
330 return true;
331
332 fail:
333 vmsg_close_fds(vmsg);
334
335 return false;
336 }
337
338 static bool
339 vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
340 {
341 int rc;
342 uint8_t *p = (uint8_t *)vmsg;
343 char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
344 struct iovec iov = {
345 .iov_base = (char *)vmsg,
346 .iov_len = VHOST_USER_HDR_SIZE,
347 };
348 struct msghdr msg = {
349 .msg_iov = &iov,
350 .msg_iovlen = 1,
351 .msg_control = control,
352 };
353 struct cmsghdr *cmsg;
354
355 memset(control, 0, sizeof(control));
356 assert(vmsg->fd_num <= VHOST_MEMORY_BASELINE_NREGIONS);
357 if (vmsg->fd_num > 0) {
358 size_t fdsize = vmsg->fd_num * sizeof(int);
359 msg.msg_controllen = CMSG_SPACE(fdsize);
360 cmsg = CMSG_FIRSTHDR(&msg);
361 cmsg->cmsg_len = CMSG_LEN(fdsize);
362 cmsg->cmsg_level = SOL_SOCKET;
363 cmsg->cmsg_type = SCM_RIGHTS;
364 memcpy(CMSG_DATA(cmsg), vmsg->fds, fdsize);
365 } else {
366 msg.msg_controllen = 0;
367 }
368
369 do {
370 rc = sendmsg(conn_fd, &msg, 0);
371 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
372
373 if (vmsg->size) {
374 do {
375 if (vmsg->data) {
376 rc = write(conn_fd, vmsg->data, vmsg->size);
377 } else {
378 rc = write(conn_fd, p + VHOST_USER_HDR_SIZE, vmsg->size);
379 }
380 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
381 }
382
383 if (rc <= 0) {
384 vu_panic(dev, "Error while writing: %s", strerror(errno));
385 return false;
386 }
387
388 return true;
389 }
390
391 static bool
392 vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
393 {
394 /* Set the version in the flags when sending the reply */
395 vmsg->flags &= ~VHOST_USER_VERSION_MASK;
396 vmsg->flags |= VHOST_USER_VERSION;
397 vmsg->flags |= VHOST_USER_REPLY_MASK;
398
399 return vu_message_write(dev, conn_fd, vmsg);
400 }
401
402 /*
403 * Processes a reply on the slave channel.
404 * Entered with slave_mutex held and releases it before exit.
405 * Returns true on success.
406 */
407 static bool
408 vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
409 {
410 VhostUserMsg msg_reply;
411 bool result = false;
412
413 if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
414 result = true;
415 goto out;
416 }
417
418 if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
419 goto out;
420 }
421
422 if (msg_reply.request != vmsg->request) {
423 DPRINT("Received unexpected msg type. Expected %d received %d",
424 vmsg->request, msg_reply.request);
425 goto out;
426 }
427
428 result = msg_reply.payload.u64 == 0;
429
430 out:
431 pthread_mutex_unlock(&dev->slave_mutex);
432 return result;
433 }
434
435 /* Kick the log_call_fd if required. */
436 static void
437 vu_log_kick(VuDev *dev)
438 {
439 if (dev->log_call_fd != -1) {
440 DPRINT("Kicking the QEMU's log...\n");
441 if (eventfd_write(dev->log_call_fd, 1) < 0) {
442 vu_panic(dev, "Error writing eventfd: %s", strerror(errno));
443 }
444 }
445 }
446
447 static void
448 vu_log_page(uint8_t *log_table, uint64_t page)
449 {
450 DPRINT("Logged dirty guest page: %"PRId64"\n", page);
451 qatomic_or(&log_table[page / 8], 1 << (page % 8));
452 }
453
454 static void
455 vu_log_write(VuDev *dev, uint64_t address, uint64_t length)
456 {
457 uint64_t page;
458
459 if (!(dev->features & (1ULL << VHOST_F_LOG_ALL)) ||
460 !dev->log_table || !length) {
461 return;
462 }
463
464 assert(dev->log_size > ((address + length - 1) / VHOST_LOG_PAGE / 8));
465
466 page = address / VHOST_LOG_PAGE;
467 while (page * VHOST_LOG_PAGE < address + length) {
468 vu_log_page(dev->log_table, page);
469 page += 1;
470 }
471
472 vu_log_kick(dev);
473 }
474
475 static void
476 vu_kick_cb(VuDev *dev, int condition, void *data)
477 {
478 int index = (intptr_t)data;
479 VuVirtq *vq = &dev->vq[index];
480 int sock = vq->kick_fd;
481 eventfd_t kick_data;
482 ssize_t rc;
483
484 rc = eventfd_read(sock, &kick_data);
485 if (rc == -1) {
486 vu_panic(dev, "kick eventfd_read(): %s", strerror(errno));
487 dev->remove_watch(dev, dev->vq[index].kick_fd);
488 } else {
489 DPRINT("Got kick_data: %016"PRIx64" handler:%p idx:%d\n",
490 kick_data, vq->handler, index);
491 if (vq->handler) {
492 vq->handler(dev, index);
493 }
494 }
495 }
496
497 static bool
498 vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg)
499 {
500 vmsg->payload.u64 =
501 /*
502 * The following VIRTIO feature bits are supported by our virtqueue
503 * implementation:
504 */
505 1ULL << VIRTIO_F_NOTIFY_ON_EMPTY |
506 1ULL << VIRTIO_RING_F_INDIRECT_DESC |
507 1ULL << VIRTIO_RING_F_EVENT_IDX |
508 1ULL << VIRTIO_F_VERSION_1 |
509
510 /* vhost-user feature bits */
511 1ULL << VHOST_F_LOG_ALL |
512 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
513
514 if (dev->iface->get_features) {
515 vmsg->payload.u64 |= dev->iface->get_features(dev);
516 }
517
518 vmsg->size = sizeof(vmsg->payload.u64);
519 vmsg->fd_num = 0;
520
521 DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
522
523 return true;
524 }
525
526 static void
527 vu_set_enable_all_rings(VuDev *dev, bool enabled)
528 {
529 uint16_t i;
530
531 for (i = 0; i < dev->max_queues; i++) {
532 dev->vq[i].enable = enabled;
533 }
534 }
535
536 static bool
537 vu_set_features_exec(VuDev *dev, VhostUserMsg *vmsg)
538 {
539 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
540
541 dev->features = vmsg->payload.u64;
542 if (!vu_has_feature(dev, VIRTIO_F_VERSION_1)) {
543 /*
544 * We only support devices conforming to VIRTIO 1.0 or
545 * later
546 */
547 vu_panic(dev, "virtio legacy devices aren't supported by libvhost-user");
548 return false;
549 }
550
551 if (!(dev->features & VHOST_USER_F_PROTOCOL_FEATURES)) {
552 vu_set_enable_all_rings(dev, true);
553 }
554
555 if (dev->iface->set_features) {
556 dev->iface->set_features(dev, dev->features);
557 }
558
559 return false;
560 }
561
562 static bool
563 vu_set_owner_exec(VuDev *dev, VhostUserMsg *vmsg)
564 {
565 return false;
566 }
567
568 static void
569 vu_close_log(VuDev *dev)
570 {
571 if (dev->log_table) {
572 if (munmap(dev->log_table, dev->log_size) != 0) {
573 perror("close log munmap() error");
574 }
575
576 dev->log_table = NULL;
577 }
578 if (dev->log_call_fd != -1) {
579 close(dev->log_call_fd);
580 dev->log_call_fd = -1;
581 }
582 }
583
584 static bool
585 vu_reset_device_exec(VuDev *dev, VhostUserMsg *vmsg)
586 {
587 vu_set_enable_all_rings(dev, false);
588
589 return false;
590 }
591
592 static bool
593 map_ring(VuDev *dev, VuVirtq *vq)
594 {
595 vq->vring.desc = qva_to_va(dev, vq->vra.desc_user_addr);
596 vq->vring.used = qva_to_va(dev, vq->vra.used_user_addr);
597 vq->vring.avail = qva_to_va(dev, vq->vra.avail_user_addr);
598
599 DPRINT("Setting virtq addresses:\n");
600 DPRINT(" vring_desc at %p\n", vq->vring.desc);
601 DPRINT(" vring_used at %p\n", vq->vring.used);
602 DPRINT(" vring_avail at %p\n", vq->vring.avail);
603
604 return !(vq->vring.desc && vq->vring.used && vq->vring.avail);
605 }
606
607 static bool
608 generate_faults(VuDev *dev) {
609 int i;
610 for (i = 0; i < dev->nregions; i++) {
611 VuDevRegion *dev_region = &dev->regions[i];
612 int ret;
613 #ifdef UFFDIO_REGISTER
614 /*
615 * We should already have an open ufd. Mark each memory
616 * range as ufd.
617 * Discard any mapping we have here; note I can't use MADV_REMOVE
618 * or fallocate to make the hole since I don't want to lose
619 * data that's already arrived in the shared process.
620 * TODO: How to do hugepage
621 */
622 ret = madvise((void *)(uintptr_t)dev_region->mmap_addr,
623 dev_region->size + dev_region->mmap_offset,
624 MADV_DONTNEED);
625 if (ret) {
626 fprintf(stderr,
627 "%s: Failed to madvise(DONTNEED) region %d: %s\n",
628 __func__, i, strerror(errno));
629 }
630 /*
631 * Turn off transparent hugepages so we dont get lose wakeups
632 * in neighbouring pages.
633 * TODO: Turn this backon later.
634 */
635 ret = madvise((void *)(uintptr_t)dev_region->mmap_addr,
636 dev_region->size + dev_region->mmap_offset,
637 MADV_NOHUGEPAGE);
638 if (ret) {
639 /*
640 * Note: This can happen legally on kernels that are configured
641 * without madvise'able hugepages
642 */
643 fprintf(stderr,
644 "%s: Failed to madvise(NOHUGEPAGE) region %d: %s\n",
645 __func__, i, strerror(errno));
646 }
647 struct uffdio_register reg_struct;
648 reg_struct.range.start = (uintptr_t)dev_region->mmap_addr;
649 reg_struct.range.len = dev_region->size + dev_region->mmap_offset;
650 reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
651
652 if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER, &reg_struct)) {
653 vu_panic(dev, "%s: Failed to userfault region %d "
654 "@%p + size:%zx offset: %zx: (ufd=%d)%s\n",
655 __func__, i,
656 dev_region->mmap_addr,
657 dev_region->size, dev_region->mmap_offset,
658 dev->postcopy_ufd, strerror(errno));
659 return false;
660 }
661 if (!(reg_struct.ioctls & ((__u64)1 << _UFFDIO_COPY))) {
662 vu_panic(dev, "%s Region (%d) doesn't support COPY",
663 __func__, i);
664 return false;
665 }
666 DPRINT("%s: region %d: Registered userfault for %"
667 PRIx64 " + %" PRIx64 "\n", __func__, i,
668 (uint64_t)reg_struct.range.start,
669 (uint64_t)reg_struct.range.len);
670 /* Now it's registered we can let the client at it */
671 if (mprotect((void *)(uintptr_t)dev_region->mmap_addr,
672 dev_region->size + dev_region->mmap_offset,
673 PROT_READ | PROT_WRITE)) {
674 vu_panic(dev, "failed to mprotect region %d for postcopy (%s)",
675 i, strerror(errno));
676 return false;
677 }
678 /* TODO: Stash 'zero' support flags somewhere */
679 #endif
680 }
681
682 return true;
683 }
684
685 static bool
686 vu_add_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
687 int i;
688 bool track_ramblocks = dev->postcopy_listening;
689 VhostUserMemoryRegion m = vmsg->payload.memreg.region, *msg_region = &m;
690 VuDevRegion *dev_region = &dev->regions[dev->nregions];
691 void *mmap_addr;
692
693 /*
694 * If we are in postcopy mode and we receive a u64 payload with a 0 value
695 * we know all the postcopy client bases have been received, and we
696 * should start generating faults.
697 */
698 if (track_ramblocks &&
699 vmsg->size == sizeof(vmsg->payload.u64) &&
700 vmsg->payload.u64 == 0) {
701 (void)generate_faults(dev);
702 return false;
703 }
704
705 DPRINT("Adding region: %u\n", dev->nregions);
706 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
707 msg_region->guest_phys_addr);
708 DPRINT(" memory_size: 0x%016"PRIx64"\n",
709 msg_region->memory_size);
710 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
711 msg_region->userspace_addr);
712 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
713 msg_region->mmap_offset);
714
715 dev_region->gpa = msg_region->guest_phys_addr;
716 dev_region->size = msg_region->memory_size;
717 dev_region->qva = msg_region->userspace_addr;
718 dev_region->mmap_offset = msg_region->mmap_offset;
719
720 /*
721 * We don't use offset argument of mmap() since the
722 * mapped address has to be page aligned, and we use huge
723 * pages.
724 */
725 if (track_ramblocks) {
726 /*
727 * In postcopy we're using PROT_NONE here to catch anyone
728 * accessing it before we userfault.
729 */
730 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
731 PROT_NONE, MAP_SHARED,
732 vmsg->fds[0], 0);
733 } else {
734 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
735 PROT_READ | PROT_WRITE, MAP_SHARED, vmsg->fds[0],
736 0);
737 }
738
739 if (mmap_addr == MAP_FAILED) {
740 vu_panic(dev, "region mmap error: %s", strerror(errno));
741 } else {
742 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
743 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
744 dev_region->mmap_addr);
745 }
746
747 close(vmsg->fds[0]);
748
749 if (track_ramblocks) {
750 /*
751 * Return the address to QEMU so that it can translate the ufd
752 * fault addresses back.
753 */
754 msg_region->userspace_addr = (uintptr_t)(mmap_addr +
755 dev_region->mmap_offset);
756
757 /* Send the message back to qemu with the addresses filled in. */
758 vmsg->fd_num = 0;
759 if (!vu_send_reply(dev, dev->sock, vmsg)) {
760 vu_panic(dev, "failed to respond to add-mem-region for postcopy");
761 return false;
762 }
763
764 DPRINT("Successfully added new region in postcopy\n");
765 dev->nregions++;
766 return false;
767
768 } else {
769 for (i = 0; i < dev->max_queues; i++) {
770 if (dev->vq[i].vring.desc) {
771 if (map_ring(dev, &dev->vq[i])) {
772 vu_panic(dev, "remapping queue %d for new memory region",
773 i);
774 }
775 }
776 }
777
778 DPRINT("Successfully added new region\n");
779 dev->nregions++;
780 vmsg_set_reply_u64(vmsg, 0);
781 return true;
782 }
783 }
784
785 static inline bool reg_equal(VuDevRegion *vudev_reg,
786 VhostUserMemoryRegion *msg_reg)
787 {
788 if (vudev_reg->gpa == msg_reg->guest_phys_addr &&
789 vudev_reg->qva == msg_reg->userspace_addr &&
790 vudev_reg->size == msg_reg->memory_size) {
791 return true;
792 }
793
794 return false;
795 }
796
797 static bool
798 vu_rem_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
799 int i, j;
800 bool found = false;
801 VuDevRegion shadow_regions[VHOST_USER_MAX_RAM_SLOTS] = {};
802 VhostUserMemoryRegion m = vmsg->payload.memreg.region, *msg_region = &m;
803
804 DPRINT("Removing region:\n");
805 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
806 msg_region->guest_phys_addr);
807 DPRINT(" memory_size: 0x%016"PRIx64"\n",
808 msg_region->memory_size);
809 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
810 msg_region->userspace_addr);
811 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
812 msg_region->mmap_offset);
813
814 for (i = 0, j = 0; i < dev->nregions; i++) {
815 if (!reg_equal(&dev->regions[i], msg_region)) {
816 shadow_regions[j].gpa = dev->regions[i].gpa;
817 shadow_regions[j].size = dev->regions[i].size;
818 shadow_regions[j].qva = dev->regions[i].qva;
819 shadow_regions[j].mmap_offset = dev->regions[i].mmap_offset;
820 j++;
821 } else {
822 found = true;
823 VuDevRegion *r = &dev->regions[i];
824 void *m = (void *) (uintptr_t) r->mmap_addr;
825
826 if (m) {
827 munmap(m, r->size + r->mmap_offset);
828 }
829 }
830 }
831
832 if (found) {
833 memcpy(dev->regions, shadow_regions,
834 sizeof(VuDevRegion) * VHOST_USER_MAX_RAM_SLOTS);
835 DPRINT("Successfully removed a region\n");
836 dev->nregions--;
837 vmsg_set_reply_u64(vmsg, 0);
838 } else {
839 vu_panic(dev, "Specified region not found\n");
840 }
841
842 return true;
843 }
844
845 static bool
846 vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
847 {
848 int i;
849 VhostUserMemory m = vmsg->payload.memory, *memory = &m;
850 dev->nregions = memory->nregions;
851
852 DPRINT("Nregions: %u\n", memory->nregions);
853 for (i = 0; i < dev->nregions; i++) {
854 void *mmap_addr;
855 VhostUserMemoryRegion *msg_region = &memory->regions[i];
856 VuDevRegion *dev_region = &dev->regions[i];
857
858 DPRINT("Region %d\n", i);
859 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
860 msg_region->guest_phys_addr);
861 DPRINT(" memory_size: 0x%016"PRIx64"\n",
862 msg_region->memory_size);
863 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
864 msg_region->userspace_addr);
865 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
866 msg_region->mmap_offset);
867
868 dev_region->gpa = msg_region->guest_phys_addr;
869 dev_region->size = msg_region->memory_size;
870 dev_region->qva = msg_region->userspace_addr;
871 dev_region->mmap_offset = msg_region->mmap_offset;
872
873 /* We don't use offset argument of mmap() since the
874 * mapped address has to be page aligned, and we use huge
875 * pages.
876 * In postcopy we're using PROT_NONE here to catch anyone
877 * accessing it before we userfault
878 */
879 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
880 PROT_NONE, MAP_SHARED,
881 vmsg->fds[i], 0);
882
883 if (mmap_addr == MAP_FAILED) {
884 vu_panic(dev, "region mmap error: %s", strerror(errno));
885 } else {
886 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
887 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
888 dev_region->mmap_addr);
889 }
890
891 /* Return the address to QEMU so that it can translate the ufd
892 * fault addresses back.
893 */
894 msg_region->userspace_addr = (uintptr_t)(mmap_addr +
895 dev_region->mmap_offset);
896 close(vmsg->fds[i]);
897 }
898
899 /* Send the message back to qemu with the addresses filled in */
900 vmsg->fd_num = 0;
901 if (!vu_send_reply(dev, dev->sock, vmsg)) {
902 vu_panic(dev, "failed to respond to set-mem-table for postcopy");
903 return false;
904 }
905
906 /* Wait for QEMU to confirm that it's registered the handler for the
907 * faults.
908 */
909 if (!dev->read_msg(dev, dev->sock, vmsg) ||
910 vmsg->size != sizeof(vmsg->payload.u64) ||
911 vmsg->payload.u64 != 0) {
912 vu_panic(dev, "failed to receive valid ack for postcopy set-mem-table");
913 return false;
914 }
915
916 /* OK, now we can go and register the memory and generate faults */
917 (void)generate_faults(dev);
918
919 return false;
920 }
921
922 static bool
923 vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg)
924 {
925 int i;
926 VhostUserMemory m = vmsg->payload.memory, *memory = &m;
927
928 for (i = 0; i < dev->nregions; i++) {
929 VuDevRegion *r = &dev->regions[i];
930 void *m = (void *) (uintptr_t) r->mmap_addr;
931
932 if (m) {
933 munmap(m, r->size + r->mmap_offset);
934 }
935 }
936 dev->nregions = memory->nregions;
937
938 if (dev->postcopy_listening) {
939 return vu_set_mem_table_exec_postcopy(dev, vmsg);
940 }
941
942 DPRINT("Nregions: %u\n", memory->nregions);
943 for (i = 0; i < dev->nregions; i++) {
944 void *mmap_addr;
945 VhostUserMemoryRegion *msg_region = &memory->regions[i];
946 VuDevRegion *dev_region = &dev->regions[i];
947
948 DPRINT("Region %d\n", i);
949 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
950 msg_region->guest_phys_addr);
951 DPRINT(" memory_size: 0x%016"PRIx64"\n",
952 msg_region->memory_size);
953 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
954 msg_region->userspace_addr);
955 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
956 msg_region->mmap_offset);
957
958 dev_region->gpa = msg_region->guest_phys_addr;
959 dev_region->size = msg_region->memory_size;
960 dev_region->qva = msg_region->userspace_addr;
961 dev_region->mmap_offset = msg_region->mmap_offset;
962
963 /* We don't use offset argument of mmap() since the
964 * mapped address has to be page aligned, and we use huge
965 * pages. */
966 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
967 PROT_READ | PROT_WRITE, MAP_SHARED,
968 vmsg->fds[i], 0);
969
970 if (mmap_addr == MAP_FAILED) {
971 vu_panic(dev, "region mmap error: %s", strerror(errno));
972 } else {
973 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
974 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
975 dev_region->mmap_addr);
976 }
977
978 close(vmsg->fds[i]);
979 }
980
981 for (i = 0; i < dev->max_queues; i++) {
982 if (dev->vq[i].vring.desc) {
983 if (map_ring(dev, &dev->vq[i])) {
984 vu_panic(dev, "remapping queue %d during setmemtable", i);
985 }
986 }
987 }
988
989 return false;
990 }
991
992 static bool
993 vu_set_log_base_exec(VuDev *dev, VhostUserMsg *vmsg)
994 {
995 int fd;
996 uint64_t log_mmap_size, log_mmap_offset;
997 void *rc;
998
999 if (vmsg->fd_num != 1 ||
1000 vmsg->size != sizeof(vmsg->payload.log)) {
1001 vu_panic(dev, "Invalid log_base message");
1002 return true;
1003 }
1004
1005 fd = vmsg->fds[0];
1006 log_mmap_offset = vmsg->payload.log.mmap_offset;
1007 log_mmap_size = vmsg->payload.log.mmap_size;
1008 DPRINT("Log mmap_offset: %"PRId64"\n", log_mmap_offset);
1009 DPRINT("Log mmap_size: %"PRId64"\n", log_mmap_size);
1010
1011 rc = mmap(0, log_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
1012 log_mmap_offset);
1013 close(fd);
1014 if (rc == MAP_FAILED) {
1015 perror("log mmap error");
1016 }
1017
1018 if (dev->log_table) {
1019 munmap(dev->log_table, dev->log_size);
1020 }
1021 dev->log_table = rc;
1022 dev->log_size = log_mmap_size;
1023
1024 vmsg->size = sizeof(vmsg->payload.u64);
1025 vmsg->fd_num = 0;
1026
1027 return true;
1028 }
1029
1030 static bool
1031 vu_set_log_fd_exec(VuDev *dev, VhostUserMsg *vmsg)
1032 {
1033 if (vmsg->fd_num != 1) {
1034 vu_panic(dev, "Invalid log_fd message");
1035 return false;
1036 }
1037
1038 if (dev->log_call_fd != -1) {
1039 close(dev->log_call_fd);
1040 }
1041 dev->log_call_fd = vmsg->fds[0];
1042 DPRINT("Got log_call_fd: %d\n", vmsg->fds[0]);
1043
1044 return false;
1045 }
1046
1047 static bool
1048 vu_set_vring_num_exec(VuDev *dev, VhostUserMsg *vmsg)
1049 {
1050 unsigned int index = vmsg->payload.state.index;
1051 unsigned int num = vmsg->payload.state.num;
1052
1053 DPRINT("State.index: %u\n", index);
1054 DPRINT("State.num: %u\n", num);
1055 dev->vq[index].vring.num = num;
1056
1057 return false;
1058 }
1059
1060 static bool
1061 vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg)
1062 {
1063 struct vhost_vring_addr addr = vmsg->payload.addr, *vra = &addr;
1064 unsigned int index = vra->index;
1065 VuVirtq *vq = &dev->vq[index];
1066
1067 DPRINT("vhost_vring_addr:\n");
1068 DPRINT(" index: %d\n", vra->index);
1069 DPRINT(" flags: %d\n", vra->flags);
1070 DPRINT(" desc_user_addr: 0x%016" PRIx64 "\n", vra->desc_user_addr);
1071 DPRINT(" used_user_addr: 0x%016" PRIx64 "\n", vra->used_user_addr);
1072 DPRINT(" avail_user_addr: 0x%016" PRIx64 "\n", vra->avail_user_addr);
1073 DPRINT(" log_guest_addr: 0x%016" PRIx64 "\n", vra->log_guest_addr);
1074
1075 vq->vra = *vra;
1076 vq->vring.flags = vra->flags;
1077 vq->vring.log_guest_addr = vra->log_guest_addr;
1078
1079
1080 if (map_ring(dev, vq)) {
1081 vu_panic(dev, "Invalid vring_addr message");
1082 return false;
1083 }
1084
1085 vq->used_idx = le16toh(vq->vring.used->idx);
1086
1087 if (vq->last_avail_idx != vq->used_idx) {
1088 bool resume = dev->iface->queue_is_processed_in_order &&
1089 dev->iface->queue_is_processed_in_order(dev, index);
1090
1091 DPRINT("Last avail index != used index: %u != %u%s\n",
1092 vq->last_avail_idx, vq->used_idx,
1093 resume ? ", resuming" : "");
1094
1095 if (resume) {
1096 vq->shadow_avail_idx = vq->last_avail_idx = vq->used_idx;
1097 }
1098 }
1099
1100 return false;
1101 }
1102
1103 static bool
1104 vu_set_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1105 {
1106 unsigned int index = vmsg->payload.state.index;
1107 unsigned int num = vmsg->payload.state.num;
1108
1109 DPRINT("State.index: %u\n", index);
1110 DPRINT("State.num: %u\n", num);
1111 dev->vq[index].shadow_avail_idx = dev->vq[index].last_avail_idx = num;
1112
1113 return false;
1114 }
1115
1116 static bool
1117 vu_get_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1118 {
1119 unsigned int index = vmsg->payload.state.index;
1120
1121 DPRINT("State.index: %u\n", index);
1122 vmsg->payload.state.num = dev->vq[index].last_avail_idx;
1123 vmsg->size = sizeof(vmsg->payload.state);
1124
1125 dev->vq[index].started = false;
1126 if (dev->iface->queue_set_started) {
1127 dev->iface->queue_set_started(dev, index, false);
1128 }
1129
1130 if (dev->vq[index].call_fd != -1) {
1131 close(dev->vq[index].call_fd);
1132 dev->vq[index].call_fd = -1;
1133 }
1134 if (dev->vq[index].kick_fd != -1) {
1135 dev->remove_watch(dev, dev->vq[index].kick_fd);
1136 close(dev->vq[index].kick_fd);
1137 dev->vq[index].kick_fd = -1;
1138 }
1139
1140 return true;
1141 }
1142
1143 static bool
1144 vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
1145 {
1146 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1147 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1148
1149 if (index >= dev->max_queues) {
1150 vmsg_close_fds(vmsg);
1151 vu_panic(dev, "Invalid queue index: %u", index);
1152 return false;
1153 }
1154
1155 if (nofd) {
1156 vmsg_close_fds(vmsg);
1157 return true;
1158 }
1159
1160 if (vmsg->fd_num != 1) {
1161 vmsg_close_fds(vmsg);
1162 vu_panic(dev, "Invalid fds in request: %d", vmsg->request);
1163 return false;
1164 }
1165
1166 return true;
1167 }
1168
1169 static int
1170 inflight_desc_compare(const void *a, const void *b)
1171 {
1172 VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
1173 *desc1 = (VuVirtqInflightDesc *)b;
1174
1175 if (desc1->counter > desc0->counter &&
1176 (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
1177 return 1;
1178 }
1179
1180 return -1;
1181 }
1182
1183 static int
1184 vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
1185 {
1186 int i = 0;
1187
1188 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
1189 return 0;
1190 }
1191
1192 if (unlikely(!vq->inflight)) {
1193 return -1;
1194 }
1195
1196 if (unlikely(!vq->inflight->version)) {
1197 /* initialize the buffer */
1198 vq->inflight->version = INFLIGHT_VERSION;
1199 return 0;
1200 }
1201
1202 vq->used_idx = le16toh(vq->vring.used->idx);
1203 vq->resubmit_num = 0;
1204 vq->resubmit_list = NULL;
1205 vq->counter = 0;
1206
1207 if (unlikely(vq->inflight->used_idx != vq->used_idx)) {
1208 vq->inflight->desc[vq->inflight->last_batch_head].inflight = 0;
1209
1210 barrier();
1211
1212 vq->inflight->used_idx = vq->used_idx;
1213 }
1214
1215 for (i = 0; i < vq->inflight->desc_num; i++) {
1216 if (vq->inflight->desc[i].inflight == 1) {
1217 vq->inuse++;
1218 }
1219 }
1220
1221 vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
1222
1223 if (vq->inuse) {
1224 vq->resubmit_list = calloc(vq->inuse, sizeof(VuVirtqInflightDesc));
1225 if (!vq->resubmit_list) {
1226 return -1;
1227 }
1228
1229 for (i = 0; i < vq->inflight->desc_num; i++) {
1230 if (vq->inflight->desc[i].inflight) {
1231 vq->resubmit_list[vq->resubmit_num].index = i;
1232 vq->resubmit_list[vq->resubmit_num].counter =
1233 vq->inflight->desc[i].counter;
1234 vq->resubmit_num++;
1235 }
1236 }
1237
1238 if (vq->resubmit_num > 1) {
1239 qsort(vq->resubmit_list, vq->resubmit_num,
1240 sizeof(VuVirtqInflightDesc), inflight_desc_compare);
1241 }
1242 vq->counter = vq->resubmit_list[0].counter + 1;
1243 }
1244
1245 /* in case of I/O hang after reconnecting */
1246 if (eventfd_write(vq->kick_fd, 1)) {
1247 return -1;
1248 }
1249
1250 return 0;
1251 }
1252
1253 static bool
1254 vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
1255 {
1256 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1257 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1258
1259 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1260
1261 if (!vu_check_queue_msg_file(dev, vmsg)) {
1262 return false;
1263 }
1264
1265 if (dev->vq[index].kick_fd != -1) {
1266 dev->remove_watch(dev, dev->vq[index].kick_fd);
1267 close(dev->vq[index].kick_fd);
1268 dev->vq[index].kick_fd = -1;
1269 }
1270
1271 dev->vq[index].kick_fd = nofd ? -1 : vmsg->fds[0];
1272 DPRINT("Got kick_fd: %d for vq: %d\n", dev->vq[index].kick_fd, index);
1273
1274 dev->vq[index].started = true;
1275 if (dev->iface->queue_set_started) {
1276 dev->iface->queue_set_started(dev, index, true);
1277 }
1278
1279 if (dev->vq[index].kick_fd != -1 && dev->vq[index].handler) {
1280 dev->set_watch(dev, dev->vq[index].kick_fd, VU_WATCH_IN,
1281 vu_kick_cb, (void *)(long)index);
1282
1283 DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
1284 dev->vq[index].kick_fd, index);
1285 }
1286
1287 if (vu_check_queue_inflights(dev, &dev->vq[index])) {
1288 vu_panic(dev, "Failed to check inflights for vq: %d\n", index);
1289 }
1290
1291 return false;
1292 }
1293
1294 void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
1295 vu_queue_handler_cb handler)
1296 {
1297 int qidx = vq - dev->vq;
1298
1299 vq->handler = handler;
1300 if (vq->kick_fd >= 0) {
1301 if (handler) {
1302 dev->set_watch(dev, vq->kick_fd, VU_WATCH_IN,
1303 vu_kick_cb, (void *)(long)qidx);
1304 } else {
1305 dev->remove_watch(dev, vq->kick_fd);
1306 }
1307 }
1308 }
1309
1310 bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
1311 int size, int offset)
1312 {
1313 int qidx = vq - dev->vq;
1314 int fd_num = 0;
1315 VhostUserMsg vmsg = {
1316 .request = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
1317 .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1318 .size = sizeof(vmsg.payload.area),
1319 .payload.area = {
1320 .u64 = qidx & VHOST_USER_VRING_IDX_MASK,
1321 .size = size,
1322 .offset = offset,
1323 },
1324 };
1325
1326 if (fd == -1) {
1327 vmsg.payload.area.u64 |= VHOST_USER_VRING_NOFD_MASK;
1328 } else {
1329 vmsg.fds[fd_num++] = fd;
1330 }
1331
1332 vmsg.fd_num = fd_num;
1333
1334 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) {
1335 return false;
1336 }
1337
1338 pthread_mutex_lock(&dev->slave_mutex);
1339 if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {
1340 pthread_mutex_unlock(&dev->slave_mutex);
1341 return false;
1342 }
1343
1344 /* Also unlocks the slave_mutex */
1345 return vu_process_message_reply(dev, &vmsg);
1346 }
1347
1348 static bool
1349 vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
1350 {
1351 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1352 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1353
1354 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1355
1356 if (!vu_check_queue_msg_file(dev, vmsg)) {
1357 return false;
1358 }
1359
1360 if (dev->vq[index].call_fd != -1) {
1361 close(dev->vq[index].call_fd);
1362 dev->vq[index].call_fd = -1;
1363 }
1364
1365 dev->vq[index].call_fd = nofd ? -1 : vmsg->fds[0];
1366
1367 /* in case of I/O hang after reconnecting */
1368 if (dev->vq[index].call_fd != -1 && eventfd_write(vmsg->fds[0], 1)) {
1369 return -1;
1370 }
1371
1372 DPRINT("Got call_fd: %d for vq: %d\n", dev->vq[index].call_fd, index);
1373
1374 return false;
1375 }
1376
1377 static bool
1378 vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg)
1379 {
1380 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1381 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1382
1383 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1384
1385 if (!vu_check_queue_msg_file(dev, vmsg)) {
1386 return false;
1387 }
1388
1389 if (dev->vq[index].err_fd != -1) {
1390 close(dev->vq[index].err_fd);
1391 dev->vq[index].err_fd = -1;
1392 }
1393
1394 dev->vq[index].err_fd = nofd ? -1 : vmsg->fds[0];
1395
1396 return false;
1397 }
1398
1399 static bool
1400 vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
1401 {
1402 /*
1403 * Note that we support, but intentionally do not set,
1404 * VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS. This means that
1405 * a device implementation can return it in its callback
1406 * (get_protocol_features) if it wants to use this for
1407 * simulation, but it is otherwise not desirable (if even
1408 * implemented by the master.)
1409 */
1410 uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_MQ |
1411 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
1412 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ |
1413 1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER |
1414 1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD |
1415 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |
1416 1ULL << VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS;
1417
1418 if (have_userfault()) {
1419 features |= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;
1420 }
1421
1422 if (dev->iface->get_config && dev->iface->set_config) {
1423 features |= 1ULL << VHOST_USER_PROTOCOL_F_CONFIG;
1424 }
1425
1426 if (dev->iface->get_protocol_features) {
1427 features |= dev->iface->get_protocol_features(dev);
1428 }
1429
1430 vmsg_set_reply_u64(vmsg, features);
1431 return true;
1432 }
1433
1434 static bool
1435 vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
1436 {
1437 uint64_t features = vmsg->payload.u64;
1438
1439 DPRINT("u64: 0x%016"PRIx64"\n", features);
1440
1441 dev->protocol_features = vmsg->payload.u64;
1442
1443 if (vu_has_protocol_feature(dev,
1444 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
1445 (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_REQ) ||
1446 !vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1447 /*
1448 * The use case for using messages for kick/call is simulation, to make
1449 * the kick and call synchronous. To actually get that behaviour, both
1450 * of the other features are required.
1451 * Theoretically, one could use only kick messages, or do them without
1452 * having F_REPLY_ACK, but too many (possibly pending) messages on the
1453 * socket will eventually cause the master to hang, to avoid this in
1454 * scenarios where not desired enforce that the settings are in a way
1455 * that actually enables the simulation case.
1456 */
1457 vu_panic(dev,
1458 "F_IN_BAND_NOTIFICATIONS requires F_SLAVE_REQ && F_REPLY_ACK");
1459 return false;
1460 }
1461
1462 if (dev->iface->set_protocol_features) {
1463 dev->iface->set_protocol_features(dev, features);
1464 }
1465
1466 return false;
1467 }
1468
1469 static bool
1470 vu_get_queue_num_exec(VuDev *dev, VhostUserMsg *vmsg)
1471 {
1472 vmsg_set_reply_u64(vmsg, dev->max_queues);
1473 return true;
1474 }
1475
1476 static bool
1477 vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
1478 {
1479 unsigned int index = vmsg->payload.state.index;
1480 unsigned int enable = vmsg->payload.state.num;
1481
1482 DPRINT("State.index: %u\n", index);
1483 DPRINT("State.enable: %u\n", enable);
1484
1485 if (index >= dev->max_queues) {
1486 vu_panic(dev, "Invalid vring_enable index: %u", index);
1487 return false;
1488 }
1489
1490 dev->vq[index].enable = enable;
1491 return false;
1492 }
1493
1494 static bool
1495 vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
1496 {
1497 if (vmsg->fd_num != 1) {
1498 vu_panic(dev, "Invalid slave_req_fd message (%d fd's)", vmsg->fd_num);
1499 return false;
1500 }
1501
1502 if (dev->slave_fd != -1) {
1503 close(dev->slave_fd);
1504 }
1505 dev->slave_fd = vmsg->fds[0];
1506 DPRINT("Got slave_fd: %d\n", vmsg->fds[0]);
1507
1508 return false;
1509 }
1510
1511 static bool
1512 vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
1513 {
1514 int ret = -1;
1515
1516 if (dev->iface->get_config) {
1517 ret = dev->iface->get_config(dev, vmsg->payload.config.region,
1518 vmsg->payload.config.size);
1519 }
1520
1521 if (ret) {
1522 /* resize to zero to indicate an error to master */
1523 vmsg->size = 0;
1524 }
1525
1526 return true;
1527 }
1528
1529 static bool
1530 vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
1531 {
1532 int ret = -1;
1533
1534 if (dev->iface->set_config) {
1535 ret = dev->iface->set_config(dev, vmsg->payload.config.region,
1536 vmsg->payload.config.offset,
1537 vmsg->payload.config.size,
1538 vmsg->payload.config.flags);
1539 if (ret) {
1540 vu_panic(dev, "Set virtio configuration space failed");
1541 }
1542 }
1543
1544 return false;
1545 }
1546
1547 static bool
1548 vu_set_postcopy_advise(VuDev *dev, VhostUserMsg *vmsg)
1549 {
1550 dev->postcopy_ufd = -1;
1551 #ifdef UFFDIO_API
1552 struct uffdio_api api_struct;
1553
1554 dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
1555 vmsg->size = 0;
1556 #endif
1557
1558 if (dev->postcopy_ufd == -1) {
1559 vu_panic(dev, "Userfaultfd not available: %s", strerror(errno));
1560 goto out;
1561 }
1562
1563 #ifdef UFFDIO_API
1564 api_struct.api = UFFD_API;
1565 api_struct.features = 0;
1566 if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) {
1567 vu_panic(dev, "Failed UFFDIO_API: %s", strerror(errno));
1568 close(dev->postcopy_ufd);
1569 dev->postcopy_ufd = -1;
1570 goto out;
1571 }
1572 /* TODO: Stash feature flags somewhere */
1573 #endif
1574
1575 out:
1576 /* Return a ufd to the QEMU */
1577 vmsg->fd_num = 1;
1578 vmsg->fds[0] = dev->postcopy_ufd;
1579 return true; /* = send a reply */
1580 }
1581
1582 static bool
1583 vu_set_postcopy_listen(VuDev *dev, VhostUserMsg *vmsg)
1584 {
1585 if (dev->nregions) {
1586 vu_panic(dev, "Regions already registered at postcopy-listen");
1587 vmsg_set_reply_u64(vmsg, -1);
1588 return true;
1589 }
1590 dev->postcopy_listening = true;
1591
1592 vmsg_set_reply_u64(vmsg, 0);
1593 return true;
1594 }
1595
1596 static bool
1597 vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
1598 {
1599 DPRINT("%s: Entry\n", __func__);
1600 dev->postcopy_listening = false;
1601 if (dev->postcopy_ufd > 0) {
1602 close(dev->postcopy_ufd);
1603 dev->postcopy_ufd = -1;
1604 DPRINT("%s: Done close\n", __func__);
1605 }
1606
1607 vmsg_set_reply_u64(vmsg, 0);
1608 DPRINT("%s: exit\n", __func__);
1609 return true;
1610 }
1611
1612 static inline uint64_t
1613 vu_inflight_queue_size(uint16_t queue_size)
1614 {
1615 return ALIGN_UP(sizeof(VuDescStateSplit) * queue_size +
1616 sizeof(uint16_t), INFLIGHT_ALIGNMENT);
1617 }
1618
1619 #ifdef MFD_ALLOW_SEALING
1620 static void *
1621 memfd_alloc(const char *name, size_t size, unsigned int flags, int *fd)
1622 {
1623 void *ptr;
1624 int ret;
1625
1626 *fd = memfd_create(name, MFD_ALLOW_SEALING);
1627 if (*fd < 0) {
1628 return NULL;
1629 }
1630
1631 ret = ftruncate(*fd, size);
1632 if (ret < 0) {
1633 close(*fd);
1634 return NULL;
1635 }
1636
1637 ret = fcntl(*fd, F_ADD_SEALS, flags);
1638 if (ret < 0) {
1639 close(*fd);
1640 return NULL;
1641 }
1642
1643 ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, 0);
1644 if (ptr == MAP_FAILED) {
1645 close(*fd);
1646 return NULL;
1647 }
1648
1649 return ptr;
1650 }
1651 #endif
1652
1653 static bool
1654 vu_get_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
1655 {
1656 int fd = -1;
1657 void *addr = NULL;
1658 uint64_t mmap_size;
1659 uint16_t num_queues, queue_size;
1660
1661 if (vmsg->size != sizeof(vmsg->payload.inflight)) {
1662 vu_panic(dev, "Invalid get_inflight_fd message:%d", vmsg->size);
1663 vmsg->payload.inflight.mmap_size = 0;
1664 return true;
1665 }
1666
1667 num_queues = vmsg->payload.inflight.num_queues;
1668 queue_size = vmsg->payload.inflight.queue_size;
1669
1670 DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
1671 DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
1672
1673 mmap_size = vu_inflight_queue_size(queue_size) * num_queues;
1674
1675 #ifdef MFD_ALLOW_SEALING
1676 addr = memfd_alloc("vhost-inflight", mmap_size,
1677 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL,
1678 &fd);
1679 #else
1680 vu_panic(dev, "Not implemented: memfd support is missing");
1681 #endif
1682
1683 if (!addr) {
1684 vu_panic(dev, "Failed to alloc vhost inflight area");
1685 vmsg->payload.inflight.mmap_size = 0;
1686 return true;
1687 }
1688
1689 memset(addr, 0, mmap_size);
1690
1691 dev->inflight_info.addr = addr;
1692 dev->inflight_info.size = vmsg->payload.inflight.mmap_size = mmap_size;
1693 dev->inflight_info.fd = vmsg->fds[0] = fd;
1694 vmsg->fd_num = 1;
1695 vmsg->payload.inflight.mmap_offset = 0;
1696
1697 DPRINT("send inflight mmap_size: %"PRId64"\n",
1698 vmsg->payload.inflight.mmap_size);
1699 DPRINT("send inflight mmap offset: %"PRId64"\n",
1700 vmsg->payload.inflight.mmap_offset);
1701
1702 return true;
1703 }
1704
1705 static bool
1706 vu_set_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
1707 {
1708 int fd, i;
1709 uint64_t mmap_size, mmap_offset;
1710 uint16_t num_queues, queue_size;
1711 void *rc;
1712
1713 if (vmsg->fd_num != 1 ||
1714 vmsg->size != sizeof(vmsg->payload.inflight)) {
1715 vu_panic(dev, "Invalid set_inflight_fd message size:%d fds:%d",
1716 vmsg->size, vmsg->fd_num);
1717 return false;
1718 }
1719
1720 fd = vmsg->fds[0];
1721 mmap_size = vmsg->payload.inflight.mmap_size;
1722 mmap_offset = vmsg->payload.inflight.mmap_offset;
1723 num_queues = vmsg->payload.inflight.num_queues;
1724 queue_size = vmsg->payload.inflight.queue_size;
1725
1726 DPRINT("set_inflight_fd mmap_size: %"PRId64"\n", mmap_size);
1727 DPRINT("set_inflight_fd mmap_offset: %"PRId64"\n", mmap_offset);
1728 DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
1729 DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
1730
1731 rc = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
1732 fd, mmap_offset);
1733
1734 if (rc == MAP_FAILED) {
1735 vu_panic(dev, "set_inflight_fd mmap error: %s", strerror(errno));
1736 return false;
1737 }
1738
1739 if (dev->inflight_info.fd) {
1740 close(dev->inflight_info.fd);
1741 }
1742
1743 if (dev->inflight_info.addr) {
1744 munmap(dev->inflight_info.addr, dev->inflight_info.size);
1745 }
1746
1747 dev->inflight_info.fd = fd;
1748 dev->inflight_info.addr = rc;
1749 dev->inflight_info.size = mmap_size;
1750
1751 for (i = 0; i < num_queues; i++) {
1752 dev->vq[i].inflight = (VuVirtqInflight *)rc;
1753 dev->vq[i].inflight->desc_num = queue_size;
1754 rc = (void *)((char *)rc + vu_inflight_queue_size(queue_size));
1755 }
1756
1757 return false;
1758 }
1759
1760 static bool
1761 vu_handle_vring_kick(VuDev *dev, VhostUserMsg *vmsg)
1762 {
1763 unsigned int index = vmsg->payload.state.index;
1764
1765 if (index >= dev->max_queues) {
1766 vu_panic(dev, "Invalid queue index: %u", index);
1767 return false;
1768 }
1769
1770 DPRINT("Got kick message: handler:%p idx:%u\n",
1771 dev->vq[index].handler, index);
1772
1773 if (!dev->vq[index].started) {
1774 dev->vq[index].started = true;
1775
1776 if (dev->iface->queue_set_started) {
1777 dev->iface->queue_set_started(dev, index, true);
1778 }
1779 }
1780
1781 if (dev->vq[index].handler) {
1782 dev->vq[index].handler(dev, index);
1783 }
1784
1785 return false;
1786 }
1787
1788 static bool vu_handle_get_max_memslots(VuDev *dev, VhostUserMsg *vmsg)
1789 {
1790 vmsg->flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
1791 vmsg->size = sizeof(vmsg->payload.u64);
1792 vmsg->payload.u64 = VHOST_USER_MAX_RAM_SLOTS;
1793 vmsg->fd_num = 0;
1794
1795 if (!vu_message_write(dev, dev->sock, vmsg)) {
1796 vu_panic(dev, "Failed to send max ram slots: %s\n", strerror(errno));
1797 }
1798
1799 DPRINT("u64: 0x%016"PRIx64"\n", (uint64_t) VHOST_USER_MAX_RAM_SLOTS);
1800
1801 return false;
1802 }
1803
1804 static bool
1805 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
1806 {
1807 int do_reply = 0;
1808
1809 /* Print out generic part of the request. */
1810 DPRINT("================ Vhost user message ================\n");
1811 DPRINT("Request: %s (%d)\n", vu_request_to_string(vmsg->request),
1812 vmsg->request);
1813 DPRINT("Flags: 0x%x\n", vmsg->flags);
1814 DPRINT("Size: %u\n", vmsg->size);
1815
1816 if (vmsg->fd_num) {
1817 int i;
1818 DPRINT("Fds:");
1819 for (i = 0; i < vmsg->fd_num; i++) {
1820 DPRINT(" %d", vmsg->fds[i]);
1821 }
1822 DPRINT("\n");
1823 }
1824
1825 if (dev->iface->process_msg &&
1826 dev->iface->process_msg(dev, vmsg, &do_reply)) {
1827 return do_reply;
1828 }
1829
1830 switch (vmsg->request) {
1831 case VHOST_USER_GET_FEATURES:
1832 return vu_get_features_exec(dev, vmsg);
1833 case VHOST_USER_SET_FEATURES:
1834 return vu_set_features_exec(dev, vmsg);
1835 case VHOST_USER_GET_PROTOCOL_FEATURES:
1836 return vu_get_protocol_features_exec(dev, vmsg);
1837 case VHOST_USER_SET_PROTOCOL_FEATURES:
1838 return vu_set_protocol_features_exec(dev, vmsg);
1839 case VHOST_USER_SET_OWNER:
1840 return vu_set_owner_exec(dev, vmsg);
1841 case VHOST_USER_RESET_OWNER:
1842 return vu_reset_device_exec(dev, vmsg);
1843 case VHOST_USER_SET_MEM_TABLE:
1844 return vu_set_mem_table_exec(dev, vmsg);
1845 case VHOST_USER_SET_LOG_BASE:
1846 return vu_set_log_base_exec(dev, vmsg);
1847 case VHOST_USER_SET_LOG_FD:
1848 return vu_set_log_fd_exec(dev, vmsg);
1849 case VHOST_USER_SET_VRING_NUM:
1850 return vu_set_vring_num_exec(dev, vmsg);
1851 case VHOST_USER_SET_VRING_ADDR:
1852 return vu_set_vring_addr_exec(dev, vmsg);
1853 case VHOST_USER_SET_VRING_BASE:
1854 return vu_set_vring_base_exec(dev, vmsg);
1855 case VHOST_USER_GET_VRING_BASE:
1856 return vu_get_vring_base_exec(dev, vmsg);
1857 case VHOST_USER_SET_VRING_KICK:
1858 return vu_set_vring_kick_exec(dev, vmsg);
1859 case VHOST_USER_SET_VRING_CALL:
1860 return vu_set_vring_call_exec(dev, vmsg);
1861 case VHOST_USER_SET_VRING_ERR:
1862 return vu_set_vring_err_exec(dev, vmsg);
1863 case VHOST_USER_GET_QUEUE_NUM:
1864 return vu_get_queue_num_exec(dev, vmsg);
1865 case VHOST_USER_SET_VRING_ENABLE:
1866 return vu_set_vring_enable_exec(dev, vmsg);
1867 case VHOST_USER_SET_SLAVE_REQ_FD:
1868 return vu_set_slave_req_fd(dev, vmsg);
1869 case VHOST_USER_GET_CONFIG:
1870 return vu_get_config(dev, vmsg);
1871 case VHOST_USER_SET_CONFIG:
1872 return vu_set_config(dev, vmsg);
1873 case VHOST_USER_NONE:
1874 /* if you need processing before exit, override iface->process_msg */
1875 exit(0);
1876 case VHOST_USER_POSTCOPY_ADVISE:
1877 return vu_set_postcopy_advise(dev, vmsg);
1878 case VHOST_USER_POSTCOPY_LISTEN:
1879 return vu_set_postcopy_listen(dev, vmsg);
1880 case VHOST_USER_POSTCOPY_END:
1881 return vu_set_postcopy_end(dev, vmsg);
1882 case VHOST_USER_GET_INFLIGHT_FD:
1883 return vu_get_inflight_fd(dev, vmsg);
1884 case VHOST_USER_SET_INFLIGHT_FD:
1885 return vu_set_inflight_fd(dev, vmsg);
1886 case VHOST_USER_VRING_KICK:
1887 return vu_handle_vring_kick(dev, vmsg);
1888 case VHOST_USER_GET_MAX_MEM_SLOTS:
1889 return vu_handle_get_max_memslots(dev, vmsg);
1890 case VHOST_USER_ADD_MEM_REG:
1891 return vu_add_mem_reg(dev, vmsg);
1892 case VHOST_USER_REM_MEM_REG:
1893 return vu_rem_mem_reg(dev, vmsg);
1894 default:
1895 vmsg_close_fds(vmsg);
1896 vu_panic(dev, "Unhandled request: %d", vmsg->request);
1897 }
1898
1899 return false;
1900 }
1901
1902 bool
1903 vu_dispatch(VuDev *dev)
1904 {
1905 VhostUserMsg vmsg = { 0, };
1906 int reply_requested;
1907 bool need_reply, success = false;
1908
1909 if (!dev->read_msg(dev, dev->sock, &vmsg)) {
1910 goto end;
1911 }
1912
1913 need_reply = vmsg.flags & VHOST_USER_NEED_REPLY_MASK;
1914
1915 reply_requested = vu_process_message(dev, &vmsg);
1916 if (!reply_requested && need_reply) {
1917 vmsg_set_reply_u64(&vmsg, 0);
1918 reply_requested = 1;
1919 }
1920
1921 if (!reply_requested) {
1922 success = true;
1923 goto end;
1924 }
1925
1926 if (!vu_send_reply(dev, dev->sock, &vmsg)) {
1927 goto end;
1928 }
1929
1930 success = true;
1931
1932 end:
1933 free(vmsg.data);
1934 return success;
1935 }
1936
1937 void
1938 vu_deinit(VuDev *dev)
1939 {
1940 int i;
1941
1942 for (i = 0; i < dev->nregions; i++) {
1943 VuDevRegion *r = &dev->regions[i];
1944 void *m = (void *) (uintptr_t) r->mmap_addr;
1945 if (m != MAP_FAILED) {
1946 munmap(m, r->size + r->mmap_offset);
1947 }
1948 }
1949 dev->nregions = 0;
1950
1951 for (i = 0; i < dev->max_queues; i++) {
1952 VuVirtq *vq = &dev->vq[i];
1953
1954 if (vq->call_fd != -1) {
1955 close(vq->call_fd);
1956 vq->call_fd = -1;
1957 }
1958
1959 if (vq->kick_fd != -1) {
1960 dev->remove_watch(dev, vq->kick_fd);
1961 close(vq->kick_fd);
1962 vq->kick_fd = -1;
1963 }
1964
1965 if (vq->err_fd != -1) {
1966 close(vq->err_fd);
1967 vq->err_fd = -1;
1968 }
1969
1970 if (vq->resubmit_list) {
1971 free(vq->resubmit_list);
1972 vq->resubmit_list = NULL;
1973 }
1974
1975 vq->inflight = NULL;
1976 }
1977
1978 if (dev->inflight_info.addr) {
1979 munmap(dev->inflight_info.addr, dev->inflight_info.size);
1980 dev->inflight_info.addr = NULL;
1981 }
1982
1983 if (dev->inflight_info.fd > 0) {
1984 close(dev->inflight_info.fd);
1985 dev->inflight_info.fd = -1;
1986 }
1987
1988 vu_close_log(dev);
1989 if (dev->slave_fd != -1) {
1990 close(dev->slave_fd);
1991 dev->slave_fd = -1;
1992 }
1993 pthread_mutex_destroy(&dev->slave_mutex);
1994
1995 if (dev->sock != -1) {
1996 close(dev->sock);
1997 }
1998
1999 free(dev->vq);
2000 dev->vq = NULL;
2001 }
2002
2003 bool
2004 vu_init(VuDev *dev,
2005 uint16_t max_queues,
2006 int socket,
2007 vu_panic_cb panic,
2008 vu_read_msg_cb read_msg,
2009 vu_set_watch_cb set_watch,
2010 vu_remove_watch_cb remove_watch,
2011 const VuDevIface *iface)
2012 {
2013 uint16_t i;
2014
2015 assert(max_queues > 0);
2016 assert(socket >= 0);
2017 assert(set_watch);
2018 assert(remove_watch);
2019 assert(iface);
2020 assert(panic);
2021
2022 memset(dev, 0, sizeof(*dev));
2023
2024 dev->sock = socket;
2025 dev->panic = panic;
2026 dev->read_msg = read_msg ? read_msg : vu_message_read_default;
2027 dev->set_watch = set_watch;
2028 dev->remove_watch = remove_watch;
2029 dev->iface = iface;
2030 dev->log_call_fd = -1;
2031 pthread_mutex_init(&dev->slave_mutex, NULL);
2032 dev->slave_fd = -1;
2033 dev->max_queues = max_queues;
2034
2035 dev->vq = malloc(max_queues * sizeof(dev->vq[0]));
2036 if (!dev->vq) {
2037 DPRINT("%s: failed to malloc virtqueues\n", __func__);
2038 return false;
2039 }
2040
2041 for (i = 0; i < max_queues; i++) {
2042 dev->vq[i] = (VuVirtq) {
2043 .call_fd = -1, .kick_fd = -1, .err_fd = -1,
2044 .notification = true,
2045 };
2046 }
2047
2048 return true;
2049 }
2050
2051 VuVirtq *
2052 vu_get_queue(VuDev *dev, int qidx)
2053 {
2054 assert(qidx < dev->max_queues);
2055 return &dev->vq[qidx];
2056 }
2057
2058 bool
2059 vu_queue_enabled(VuDev *dev, VuVirtq *vq)
2060 {
2061 return vq->enable;
2062 }
2063
2064 bool
2065 vu_queue_started(const VuDev *dev, const VuVirtq *vq)
2066 {
2067 return vq->started;
2068 }
2069
2070 static inline uint16_t
2071 vring_avail_flags(VuVirtq *vq)
2072 {
2073 return le16toh(vq->vring.avail->flags);
2074 }
2075
2076 static inline uint16_t
2077 vring_avail_idx(VuVirtq *vq)
2078 {
2079 vq->shadow_avail_idx = le16toh(vq->vring.avail->idx);
2080
2081 return vq->shadow_avail_idx;
2082 }
2083
2084 static inline uint16_t
2085 vring_avail_ring(VuVirtq *vq, int i)
2086 {
2087 return le16toh(vq->vring.avail->ring[i]);
2088 }
2089
2090 static inline uint16_t
2091 vring_get_used_event(VuVirtq *vq)
2092 {
2093 return vring_avail_ring(vq, vq->vring.num);
2094 }
2095
2096 static int
2097 virtqueue_num_heads(VuDev *dev, VuVirtq *vq, unsigned int idx)
2098 {
2099 uint16_t num_heads = vring_avail_idx(vq) - idx;
2100
2101 /* Check it isn't doing very strange things with descriptor numbers. */
2102 if (num_heads > vq->vring.num) {
2103 vu_panic(dev, "Guest moved used index from %u to %u",
2104 idx, vq->shadow_avail_idx);
2105 return -1;
2106 }
2107 if (num_heads) {
2108 /* On success, callers read a descriptor at vq->last_avail_idx.
2109 * Make sure descriptor read does not bypass avail index read. */
2110 smp_rmb();
2111 }
2112
2113 return num_heads;
2114 }
2115
2116 static bool
2117 virtqueue_get_head(VuDev *dev, VuVirtq *vq,
2118 unsigned int idx, unsigned int *head)
2119 {
2120 /* Grab the next descriptor number they're advertising, and increment
2121 * the index we've seen. */
2122 *head = vring_avail_ring(vq, idx % vq->vring.num);
2123
2124 /* If their number is silly, that's a fatal mistake. */
2125 if (*head >= vq->vring.num) {
2126 vu_panic(dev, "Guest says index %u is available", *head);
2127 return false;
2128 }
2129
2130 return true;
2131 }
2132
2133 static int
2134 virtqueue_read_indirect_desc(VuDev *dev, struct vring_desc *desc,
2135 uint64_t addr, size_t len)
2136 {
2137 struct vring_desc *ori_desc;
2138 uint64_t read_len;
2139
2140 if (len > (VIRTQUEUE_MAX_SIZE * sizeof(struct vring_desc))) {
2141 return -1;
2142 }
2143
2144 if (len == 0) {
2145 return -1;
2146 }
2147
2148 while (len) {
2149 read_len = len;
2150 ori_desc = vu_gpa_to_va(dev, &read_len, addr);
2151 if (!ori_desc) {
2152 return -1;
2153 }
2154
2155 memcpy(desc, ori_desc, read_len);
2156 len -= read_len;
2157 addr += read_len;
2158 desc += read_len;
2159 }
2160
2161 return 0;
2162 }
2163
2164 enum {
2165 VIRTQUEUE_READ_DESC_ERROR = -1,
2166 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */
2167 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
2168 };
2169
2170 static int
2171 virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc,
2172 int i, unsigned int max, unsigned int *next)
2173 {
2174 /* If this descriptor says it doesn't chain, we're done. */
2175 if (!(le16toh(desc[i].flags) & VRING_DESC_F_NEXT)) {
2176 return VIRTQUEUE_READ_DESC_DONE;
2177 }
2178
2179 /* Check they're not leading us off end of descriptors. */
2180 *next = le16toh(desc[i].next);
2181 /* Make sure compiler knows to grab that: we don't want it changing! */
2182 smp_wmb();
2183
2184 if (*next >= max) {
2185 vu_panic(dev, "Desc next is %u", *next);
2186 return VIRTQUEUE_READ_DESC_ERROR;
2187 }
2188
2189 return VIRTQUEUE_READ_DESC_MORE;
2190 }
2191
2192 void
2193 vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes,
2194 unsigned int *out_bytes,
2195 unsigned max_in_bytes, unsigned max_out_bytes)
2196 {
2197 unsigned int idx;
2198 unsigned int total_bufs, in_total, out_total;
2199 int rc;
2200
2201 idx = vq->last_avail_idx;
2202
2203 total_bufs = in_total = out_total = 0;
2204 if (unlikely(dev->broken) ||
2205 unlikely(!vq->vring.avail)) {
2206 goto done;
2207 }
2208
2209 while ((rc = virtqueue_num_heads(dev, vq, idx)) > 0) {
2210 unsigned int max, desc_len, num_bufs, indirect = 0;
2211 uint64_t desc_addr, read_len;
2212 struct vring_desc *desc;
2213 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2214 unsigned int i;
2215
2216 max = vq->vring.num;
2217 num_bufs = total_bufs;
2218 if (!virtqueue_get_head(dev, vq, idx++, &i)) {
2219 goto err;
2220 }
2221 desc = vq->vring.desc;
2222
2223 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
2224 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
2225 vu_panic(dev, "Invalid size for indirect buffer table");
2226 goto err;
2227 }
2228
2229 /* If we've got too many, that implies a descriptor loop. */
2230 if (num_bufs >= max) {
2231 vu_panic(dev, "Looped descriptor");
2232 goto err;
2233 }
2234
2235 /* loop over the indirect descriptor table */
2236 indirect = 1;
2237 desc_addr = le64toh(desc[i].addr);
2238 desc_len = le32toh(desc[i].len);
2239 max = desc_len / sizeof(struct vring_desc);
2240 read_len = desc_len;
2241 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2242 if (unlikely(desc && read_len != desc_len)) {
2243 /* Failed to use zero copy */
2244 desc = NULL;
2245 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2246 desc_addr,
2247 desc_len)) {
2248 desc = desc_buf;
2249 }
2250 }
2251 if (!desc) {
2252 vu_panic(dev, "Invalid indirect buffer table");
2253 goto err;
2254 }
2255 num_bufs = i = 0;
2256 }
2257
2258 do {
2259 /* If we've got too many, that implies a descriptor loop. */
2260 if (++num_bufs > max) {
2261 vu_panic(dev, "Looped descriptor");
2262 goto err;
2263 }
2264
2265 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
2266 in_total += le32toh(desc[i].len);
2267 } else {
2268 out_total += le32toh(desc[i].len);
2269 }
2270 if (in_total >= max_in_bytes && out_total >= max_out_bytes) {
2271 goto done;
2272 }
2273 rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
2274 } while (rc == VIRTQUEUE_READ_DESC_MORE);
2275
2276 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
2277 goto err;
2278 }
2279
2280 if (!indirect) {
2281 total_bufs = num_bufs;
2282 } else {
2283 total_bufs++;
2284 }
2285 }
2286 if (rc < 0) {
2287 goto err;
2288 }
2289 done:
2290 if (in_bytes) {
2291 *in_bytes = in_total;
2292 }
2293 if (out_bytes) {
2294 *out_bytes = out_total;
2295 }
2296 return;
2297
2298 err:
2299 in_total = out_total = 0;
2300 goto done;
2301 }
2302
2303 bool
2304 vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes,
2305 unsigned int out_bytes)
2306 {
2307 unsigned int in_total, out_total;
2308
2309 vu_queue_get_avail_bytes(dev, vq, &in_total, &out_total,
2310 in_bytes, out_bytes);
2311
2312 return in_bytes <= in_total && out_bytes <= out_total;
2313 }
2314
2315 /* Fetch avail_idx from VQ memory only when we really need to know if
2316 * guest has added some buffers. */
2317 bool
2318 vu_queue_empty(VuDev *dev, VuVirtq *vq)
2319 {
2320 if (unlikely(dev->broken) ||
2321 unlikely(!vq->vring.avail)) {
2322 return true;
2323 }
2324
2325 if (vq->shadow_avail_idx != vq->last_avail_idx) {
2326 return false;
2327 }
2328
2329 return vring_avail_idx(vq) == vq->last_avail_idx;
2330 }
2331
2332 static bool
2333 vring_notify(VuDev *dev, VuVirtq *vq)
2334 {
2335 uint16_t old, new;
2336 bool v;
2337
2338 /* We need to expose used array entries before checking used event. */
2339 smp_mb();
2340
2341 /* Always notify when queue is empty (when feature acknowledge) */
2342 if (vu_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
2343 !vq->inuse && vu_queue_empty(dev, vq)) {
2344 return true;
2345 }
2346
2347 if (!vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2348 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
2349 }
2350
2351 v = vq->signalled_used_valid;
2352 vq->signalled_used_valid = true;
2353 old = vq->signalled_used;
2354 new = vq->signalled_used = vq->used_idx;
2355 return !v || vring_need_event(vring_get_used_event(vq), new, old);
2356 }
2357
2358 static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
2359 {
2360 if (unlikely(dev->broken) ||
2361 unlikely(!vq->vring.avail)) {
2362 return;
2363 }
2364
2365 if (!vring_notify(dev, vq)) {
2366 DPRINT("skipped notify...\n");
2367 return;
2368 }
2369
2370 if (vq->call_fd < 0 &&
2371 vu_has_protocol_feature(dev,
2372 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
2373 vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
2374 VhostUserMsg vmsg = {
2375 .request = VHOST_USER_SLAVE_VRING_CALL,
2376 .flags = VHOST_USER_VERSION,
2377 .size = sizeof(vmsg.payload.state),
2378 .payload.state = {
2379 .index = vq - dev->vq,
2380 },
2381 };
2382 bool ack = sync &&
2383 vu_has_protocol_feature(dev,
2384 VHOST_USER_PROTOCOL_F_REPLY_ACK);
2385
2386 if (ack) {
2387 vmsg.flags |= VHOST_USER_NEED_REPLY_MASK;
2388 }
2389
2390 vu_message_write(dev, dev->slave_fd, &vmsg);
2391 if (ack) {
2392 vu_message_read_default(dev, dev->slave_fd, &vmsg);
2393 }
2394 return;
2395 }
2396
2397 if (eventfd_write(vq->call_fd, 1) < 0) {
2398 vu_panic(dev, "Error writing eventfd: %s", strerror(errno));
2399 }
2400 }
2401
2402 void vu_queue_notify(VuDev *dev, VuVirtq *vq)
2403 {
2404 _vu_queue_notify(dev, vq, false);
2405 }
2406
2407 void vu_queue_notify_sync(VuDev *dev, VuVirtq *vq)
2408 {
2409 _vu_queue_notify(dev, vq, true);
2410 }
2411
2412 static inline void
2413 vring_used_flags_set_bit(VuVirtq *vq, int mask)
2414 {
2415 uint16_t *flags;
2416
2417 flags = (uint16_t *)((char*)vq->vring.used +
2418 offsetof(struct vring_used, flags));
2419 *flags = htole16(le16toh(*flags) | mask);
2420 }
2421
2422 static inline void
2423 vring_used_flags_unset_bit(VuVirtq *vq, int mask)
2424 {
2425 uint16_t *flags;
2426
2427 flags = (uint16_t *)((char*)vq->vring.used +
2428 offsetof(struct vring_used, flags));
2429 *flags = htole16(le16toh(*flags) & ~mask);
2430 }
2431
2432 static inline void
2433 vring_set_avail_event(VuVirtq *vq, uint16_t val)
2434 {
2435 uint16_t *avail;
2436
2437 if (!vq->notification) {
2438 return;
2439 }
2440
2441 avail = (uint16_t *)&vq->vring.used->ring[vq->vring.num];
2442 *avail = htole16(val);
2443 }
2444
2445 void
2446 vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int enable)
2447 {
2448 vq->notification = enable;
2449 if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2450 vring_set_avail_event(vq, vring_avail_idx(vq));
2451 } else if (enable) {
2452 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
2453 } else {
2454 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
2455 }
2456 if (enable) {
2457 /* Expose avail event/used flags before caller checks the avail idx. */
2458 smp_mb();
2459 }
2460 }
2461
2462 static bool
2463 virtqueue_map_desc(VuDev *dev,
2464 unsigned int *p_num_sg, struct iovec *iov,
2465 unsigned int max_num_sg, bool is_write,
2466 uint64_t pa, size_t sz)
2467 {
2468 unsigned num_sg = *p_num_sg;
2469
2470 assert(num_sg <= max_num_sg);
2471
2472 if (!sz) {
2473 vu_panic(dev, "virtio: zero sized buffers are not allowed");
2474 return false;
2475 }
2476
2477 while (sz) {
2478 uint64_t len = sz;
2479
2480 if (num_sg == max_num_sg) {
2481 vu_panic(dev, "virtio: too many descriptors in indirect table");
2482 return false;
2483 }
2484
2485 iov[num_sg].iov_base = vu_gpa_to_va(dev, &len, pa);
2486 if (iov[num_sg].iov_base == NULL) {
2487 vu_panic(dev, "virtio: invalid address for buffers");
2488 return false;
2489 }
2490 iov[num_sg].iov_len = len;
2491 num_sg++;
2492 sz -= len;
2493 pa += len;
2494 }
2495
2496 *p_num_sg = num_sg;
2497 return true;
2498 }
2499
2500 static void *
2501 virtqueue_alloc_element(size_t sz,
2502 unsigned out_num, unsigned in_num)
2503 {
2504 VuVirtqElement *elem;
2505 size_t in_sg_ofs = ALIGN_UP(sz, __alignof__(elem->in_sg[0]));
2506 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]);
2507 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]);
2508
2509 assert(sz >= sizeof(VuVirtqElement));
2510 elem = malloc(out_sg_end);
2511 elem->out_num = out_num;
2512 elem->in_num = in_num;
2513 elem->in_sg = (void *)elem + in_sg_ofs;
2514 elem->out_sg = (void *)elem + out_sg_ofs;
2515 return elem;
2516 }
2517
2518 static void *
2519 vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz)
2520 {
2521 struct vring_desc *desc = vq->vring.desc;
2522 uint64_t desc_addr, read_len;
2523 unsigned int desc_len;
2524 unsigned int max = vq->vring.num;
2525 unsigned int i = idx;
2526 VuVirtqElement *elem;
2527 unsigned int out_num = 0, in_num = 0;
2528 struct iovec iov[VIRTQUEUE_MAX_SIZE];
2529 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2530 int rc;
2531
2532 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
2533 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
2534 vu_panic(dev, "Invalid size for indirect buffer table");
2535 return NULL;
2536 }
2537
2538 /* loop over the indirect descriptor table */
2539 desc_addr = le64toh(desc[i].addr);
2540 desc_len = le32toh(desc[i].len);
2541 max = desc_len / sizeof(struct vring_desc);
2542 read_len = desc_len;
2543 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2544 if (unlikely(desc && read_len != desc_len)) {
2545 /* Failed to use zero copy */
2546 desc = NULL;
2547 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2548 desc_addr,
2549 desc_len)) {
2550 desc = desc_buf;
2551 }
2552 }
2553 if (!desc) {
2554 vu_panic(dev, "Invalid indirect buffer table");
2555 return NULL;
2556 }
2557 i = 0;
2558 }
2559
2560 /* Collect all the descriptors */
2561 do {
2562 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
2563 if (!virtqueue_map_desc(dev, &in_num, iov + out_num,
2564 VIRTQUEUE_MAX_SIZE - out_num, true,
2565 le64toh(desc[i].addr),
2566 le32toh(desc[i].len))) {
2567 return NULL;
2568 }
2569 } else {
2570 if (in_num) {
2571 vu_panic(dev, "Incorrect order for descriptors");
2572 return NULL;
2573 }
2574 if (!virtqueue_map_desc(dev, &out_num, iov,
2575 VIRTQUEUE_MAX_SIZE, false,
2576 le64toh(desc[i].addr),
2577 le32toh(desc[i].len))) {
2578 return NULL;
2579 }
2580 }
2581
2582 /* If we've got too many, that implies a descriptor loop. */
2583 if ((in_num + out_num) > max) {
2584 vu_panic(dev, "Looped descriptor");
2585 return NULL;
2586 }
2587 rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
2588 } while (rc == VIRTQUEUE_READ_DESC_MORE);
2589
2590 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
2591 vu_panic(dev, "read descriptor error");
2592 return NULL;
2593 }
2594
2595 /* Now copy what we have collected and mapped */
2596 elem = virtqueue_alloc_element(sz, out_num, in_num);
2597 elem->index = idx;
2598 for (i = 0; i < out_num; i++) {
2599 elem->out_sg[i] = iov[i];
2600 }
2601 for (i = 0; i < in_num; i++) {
2602 elem->in_sg[i] = iov[out_num + i];
2603 }
2604
2605 return elem;
2606 }
2607
2608 static int
2609 vu_queue_inflight_get(VuDev *dev, VuVirtq *vq, int desc_idx)
2610 {
2611 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2612 return 0;
2613 }
2614
2615 if (unlikely(!vq->inflight)) {
2616 return -1;
2617 }
2618
2619 vq->inflight->desc[desc_idx].counter = vq->counter++;
2620 vq->inflight->desc[desc_idx].inflight = 1;
2621
2622 return 0;
2623 }
2624
2625 static int
2626 vu_queue_inflight_pre_put(VuDev *dev, VuVirtq *vq, int desc_idx)
2627 {
2628 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2629 return 0;
2630 }
2631
2632 if (unlikely(!vq->inflight)) {
2633 return -1;
2634 }
2635
2636 vq->inflight->last_batch_head = desc_idx;
2637
2638 return 0;
2639 }
2640
2641 static int
2642 vu_queue_inflight_post_put(VuDev *dev, VuVirtq *vq, int desc_idx)
2643 {
2644 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2645 return 0;
2646 }
2647
2648 if (unlikely(!vq->inflight)) {
2649 return -1;
2650 }
2651
2652 barrier();
2653
2654 vq->inflight->desc[desc_idx].inflight = 0;
2655
2656 barrier();
2657
2658 vq->inflight->used_idx = vq->used_idx;
2659
2660 return 0;
2661 }
2662
2663 void *
2664 vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
2665 {
2666 int i;
2667 unsigned int head;
2668 VuVirtqElement *elem;
2669
2670 if (unlikely(dev->broken) ||
2671 unlikely(!vq->vring.avail)) {
2672 return NULL;
2673 }
2674
2675 if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
2676 i = (--vq->resubmit_num);
2677 elem = vu_queue_map_desc(dev, vq, vq->resubmit_list[i].index, sz);
2678
2679 if (!vq->resubmit_num) {
2680 free(vq->resubmit_list);
2681 vq->resubmit_list = NULL;
2682 }
2683
2684 return elem;
2685 }
2686
2687 if (vu_queue_empty(dev, vq)) {
2688 return NULL;
2689 }
2690 /*
2691 * Needed after virtio_queue_empty(), see comment in
2692 * virtqueue_num_heads().
2693 */
2694 smp_rmb();
2695
2696 if (vq->inuse >= vq->vring.num) {
2697 vu_panic(dev, "Virtqueue size exceeded");
2698 return NULL;
2699 }
2700
2701 if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
2702 return NULL;
2703 }
2704
2705 if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2706 vring_set_avail_event(vq, vq->last_avail_idx);
2707 }
2708
2709 elem = vu_queue_map_desc(dev, vq, head, sz);
2710
2711 if (!elem) {
2712 return NULL;
2713 }
2714
2715 vq->inuse++;
2716
2717 vu_queue_inflight_get(dev, vq, head);
2718
2719 return elem;
2720 }
2721
2722 static void
2723 vu_queue_detach_element(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
2724 size_t len)
2725 {
2726 vq->inuse--;
2727 /* unmap, when DMA support is added */
2728 }
2729
2730 void
2731 vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
2732 size_t len)
2733 {
2734 vq->last_avail_idx--;
2735 vu_queue_detach_element(dev, vq, elem, len);
2736 }
2737
2738 bool
2739 vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num)
2740 {
2741 if (num > vq->inuse) {
2742 return false;
2743 }
2744 vq->last_avail_idx -= num;
2745 vq->inuse -= num;
2746 return true;
2747 }
2748
2749 static inline
2750 void vring_used_write(VuDev *dev, VuVirtq *vq,
2751 struct vring_used_elem *uelem, int i)
2752 {
2753 struct vring_used *used = vq->vring.used;
2754
2755 used->ring[i] = *uelem;
2756 vu_log_write(dev, vq->vring.log_guest_addr +
2757 offsetof(struct vring_used, ring[i]),
2758 sizeof(used->ring[i]));
2759 }
2760
2761
2762 static void
2763 vu_log_queue_fill(VuDev *dev, VuVirtq *vq,
2764 const VuVirtqElement *elem,
2765 unsigned int len)
2766 {
2767 struct vring_desc *desc = vq->vring.desc;
2768 unsigned int i, max, min, desc_len;
2769 uint64_t desc_addr, read_len;
2770 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2771 unsigned num_bufs = 0;
2772
2773 max = vq->vring.num;
2774 i = elem->index;
2775
2776 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
2777 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
2778 vu_panic(dev, "Invalid size for indirect buffer table");
2779 return;
2780 }
2781
2782 /* loop over the indirect descriptor table */
2783 desc_addr = le64toh(desc[i].addr);
2784 desc_len = le32toh(desc[i].len);
2785 max = desc_len / sizeof(struct vring_desc);
2786 read_len = desc_len;
2787 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2788 if (unlikely(desc && read_len != desc_len)) {
2789 /* Failed to use zero copy */
2790 desc = NULL;
2791 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2792 desc_addr,
2793 desc_len)) {
2794 desc = desc_buf;
2795 }
2796 }
2797 if (!desc) {
2798 vu_panic(dev, "Invalid indirect buffer table");
2799 return;
2800 }
2801 i = 0;
2802 }
2803
2804 do {
2805 if (++num_bufs > max) {
2806 vu_panic(dev, "Looped descriptor");
2807 return;
2808 }
2809
2810 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
2811 min = MIN(le32toh(desc[i].len), len);
2812 vu_log_write(dev, le64toh(desc[i].addr), min);
2813 len -= min;
2814 }
2815
2816 } while (len > 0 &&
2817 (virtqueue_read_next_desc(dev, desc, i, max, &i)
2818 == VIRTQUEUE_READ_DESC_MORE));
2819 }
2820
2821 void
2822 vu_queue_fill(VuDev *dev, VuVirtq *vq,
2823 const VuVirtqElement *elem,
2824 unsigned int len, unsigned int idx)
2825 {
2826 struct vring_used_elem uelem;
2827
2828 if (unlikely(dev->broken) ||
2829 unlikely(!vq->vring.avail)) {
2830 return;
2831 }
2832
2833 vu_log_queue_fill(dev, vq, elem, len);
2834
2835 idx = (idx + vq->used_idx) % vq->vring.num;
2836
2837 uelem.id = htole32(elem->index);
2838 uelem.len = htole32(len);
2839 vring_used_write(dev, vq, &uelem, idx);
2840 }
2841
2842 static inline
2843 void vring_used_idx_set(VuDev *dev, VuVirtq *vq, uint16_t val)
2844 {
2845 vq->vring.used->idx = htole16(val);
2846 vu_log_write(dev,
2847 vq->vring.log_guest_addr + offsetof(struct vring_used, idx),
2848 sizeof(vq->vring.used->idx));
2849
2850 vq->used_idx = val;
2851 }
2852
2853 void
2854 vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int count)
2855 {
2856 uint16_t old, new;
2857
2858 if (unlikely(dev->broken) ||
2859 unlikely(!vq->vring.avail)) {
2860 return;
2861 }
2862
2863 /* Make sure buffer is written before we update index. */
2864 smp_wmb();
2865
2866 old = vq->used_idx;
2867 new = old + count;
2868 vring_used_idx_set(dev, vq, new);
2869 vq->inuse -= count;
2870 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) {
2871 vq->signalled_used_valid = false;
2872 }
2873 }
2874
2875 void
2876 vu_queue_push(VuDev *dev, VuVirtq *vq,
2877 const VuVirtqElement *elem, unsigned int len)
2878 {
2879 vu_queue_fill(dev, vq, elem, len, 0);
2880 vu_queue_inflight_pre_put(dev, vq, elem->index);
2881 vu_queue_flush(dev, vq, 1);
2882 vu_queue_inflight_post_put(dev, vq, elem->index);
2883 }
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