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qapi: Improve specificity of type/member descriptions
[qemu/armbru.git] / subprojects / libvhost-user / libvhost-user.c
blob0200b78e8e1a1c18d53bc79afe6b806485a34f0b
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 #ifndef _GNU_SOURCE
17 #define _GNU_SOURCE
18 #endif
19
20 /* this code avoids GLib dependency */
21 #include <stdlib.h>
22 #include <stdio.h>
23 #include <unistd.h>
24 #include <stdarg.h>
25 #include <errno.h>
26 #include <string.h>
27 #include <assert.h>
28 #include <inttypes.h>
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <sys/eventfd.h>
32 #include <sys/mman.h>
33 #include <endian.h>
34
35 #if defined(__linux__)
36 #include <sys/syscall.h>
37 #include <fcntl.h>
38 #include <sys/ioctl.h>
39 #include <linux/vhost.h>
40
41 #ifdef __NR_userfaultfd
42 #include <linux/userfaultfd.h>
43 #endif
44
45 #endif
46
47 #include "include/atomic.h"
48
49 #include "libvhost-user.h"
50
51 /* usually provided by GLib */
52 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
53 #if !defined(__clang__) && (__GNUC__ == 4 && __GNUC_MINOR__ == 4)
54 #define G_GNUC_PRINTF(format_idx, arg_idx) \
55 __attribute__((__format__(gnu_printf, format_idx, arg_idx)))
56 #else
57 #define G_GNUC_PRINTF(format_idx, arg_idx) \
58 __attribute__((__format__(__printf__, format_idx, arg_idx)))
59 #endif
60 #else /* !__GNUC__ */
61 #define G_GNUC_PRINTF(format_idx, arg_idx)
62 #endif /* !__GNUC__ */
63 #ifndef MIN
64 #define MIN(x, y) ({ \
65 __typeof__(x) _min1 = (x); \
66 __typeof__(y) _min2 = (y); \
67 (void) (&_min1 == &_min2); \
68 _min1 < _min2 ? _min1 : _min2; })
69 #endif
70
71 /* Round number down to multiple */
72 #define ALIGN_DOWN(n, m) ((n) / (m) * (m))
73
74 /* Round number up to multiple */
75 #define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
76
77 #ifndef unlikely
78 #define unlikely(x) __builtin_expect(!!(x), 0)
79 #endif
80
81 /* Align each region to cache line size in inflight buffer */
82 #define INFLIGHT_ALIGNMENT 64
83
84 /* The version of inflight buffer */
85 #define INFLIGHT_VERSION 1
86
87 /* The version of the protocol we support */
88 #define VHOST_USER_VERSION 1
89 #define LIBVHOST_USER_DEBUG 0
90
91 #define DPRINT(...) \
92 do { \
93 if (LIBVHOST_USER_DEBUG) { \
94 fprintf(stderr, __VA_ARGS__); \
95 } \
96 } while (0)
97
98 static inline
99 bool has_feature(uint64_t features, unsigned int fbit)
100 {
101 assert(fbit < 64);
102 return !!(features & (1ULL << fbit));
103 }
104
105 static inline
106 bool vu_has_feature(VuDev *dev,
107 unsigned int fbit)
108 {
109 return has_feature(dev->features, fbit);
110 }
111
112 static inline bool vu_has_protocol_feature(VuDev *dev, unsigned int fbit)
113 {
114 return has_feature(dev->protocol_features, fbit);
115 }
116
117 const char *
118 vu_request_to_string(unsigned int req)
119 {
120 #define REQ(req) [req] = #req
121 static const char *vu_request_str[] = {
122 REQ(VHOST_USER_NONE),
123 REQ(VHOST_USER_GET_FEATURES),
124 REQ(VHOST_USER_SET_FEATURES),
125 REQ(VHOST_USER_SET_OWNER),
126 REQ(VHOST_USER_RESET_OWNER),
127 REQ(VHOST_USER_SET_MEM_TABLE),
128 REQ(VHOST_USER_SET_LOG_BASE),
129 REQ(VHOST_USER_SET_LOG_FD),
130 REQ(VHOST_USER_SET_VRING_NUM),
131 REQ(VHOST_USER_SET_VRING_ADDR),
132 REQ(VHOST_USER_SET_VRING_BASE),
133 REQ(VHOST_USER_GET_VRING_BASE),
134 REQ(VHOST_USER_SET_VRING_KICK),
135 REQ(VHOST_USER_SET_VRING_CALL),
136 REQ(VHOST_USER_SET_VRING_ERR),
137 REQ(VHOST_USER_GET_PROTOCOL_FEATURES),
138 REQ(VHOST_USER_SET_PROTOCOL_FEATURES),
139 REQ(VHOST_USER_GET_QUEUE_NUM),
140 REQ(VHOST_USER_SET_VRING_ENABLE),
141 REQ(VHOST_USER_SEND_RARP),
142 REQ(VHOST_USER_NET_SET_MTU),
143 REQ(VHOST_USER_SET_BACKEND_REQ_FD),
144 REQ(VHOST_USER_IOTLB_MSG),
145 REQ(VHOST_USER_SET_VRING_ENDIAN),
146 REQ(VHOST_USER_GET_CONFIG),
147 REQ(VHOST_USER_SET_CONFIG),
148 REQ(VHOST_USER_POSTCOPY_ADVISE),
149 REQ(VHOST_USER_POSTCOPY_LISTEN),
150 REQ(VHOST_USER_POSTCOPY_END),
151 REQ(VHOST_USER_GET_INFLIGHT_FD),
152 REQ(VHOST_USER_SET_INFLIGHT_FD),
153 REQ(VHOST_USER_GPU_SET_SOCKET),
154 REQ(VHOST_USER_VRING_KICK),
155 REQ(VHOST_USER_GET_MAX_MEM_SLOTS),
156 REQ(VHOST_USER_ADD_MEM_REG),
157 REQ(VHOST_USER_REM_MEM_REG),
158 REQ(VHOST_USER_MAX),
159 };
160 #undef REQ
161
162 if (req < VHOST_USER_MAX) {
163 return vu_request_str[req];
164 } else {
165 return "unknown";
166 }
167 }
168
169 static void G_GNUC_PRINTF(2, 3)
170 vu_panic(VuDev *dev, const char *msg, ...)
171 {
172 char *buf = NULL;
173 va_list ap;
174
175 va_start(ap, msg);
176 if (vasprintf(&buf, msg, ap) < 0) {
177 buf = NULL;
178 }
179 va_end(ap);
180
181 dev->broken = true;
182 dev->panic(dev, buf);
183 free(buf);
184
185 /*
186 * FIXME:
187 * find a way to call virtio_error, or perhaps close the connection?
188 */
189 }
190
191 /* Translate guest physical address to our virtual address. */
192 void *
193 vu_gpa_to_va(VuDev *dev, uint64_t *plen, uint64_t guest_addr)
194 {
195 unsigned int i;
196
197 if (*plen == 0) {
198 return NULL;
199 }
200
201 /* Find matching memory region. */
202 for (i = 0; i < dev->nregions; i++) {
203 VuDevRegion *r = &dev->regions[i];
204
205 if ((guest_addr >= r->gpa) && (guest_addr < (r->gpa + r->size))) {
206 if ((guest_addr + *plen) > (r->gpa + r->size)) {
207 *plen = r->gpa + r->size - guest_addr;
208 }
209 return (void *)(uintptr_t)
210 guest_addr - r->gpa + r->mmap_addr + r->mmap_offset;
211 }
212 }
213
214 return NULL;
215 }
216
217 /* Translate qemu virtual address to our virtual address. */
218 static void *
219 qva_to_va(VuDev *dev, uint64_t qemu_addr)
220 {
221 unsigned int i;
222
223 /* Find matching memory region. */
224 for (i = 0; i < dev->nregions; i++) {
225 VuDevRegion *r = &dev->regions[i];
226
227 if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
228 return (void *)(uintptr_t)
229 qemu_addr - r->qva + r->mmap_addr + r->mmap_offset;
230 }
231 }
232
233 return NULL;
234 }
235
236 static void
237 vmsg_close_fds(VhostUserMsg *vmsg)
238 {
239 int i;
240
241 for (i = 0; i < vmsg->fd_num; i++) {
242 close(vmsg->fds[i]);
243 }
244 }
245
246 /* Set reply payload.u64 and clear request flags and fd_num */
247 static void vmsg_set_reply_u64(VhostUserMsg *vmsg, uint64_t val)
248 {
249 vmsg->flags = 0; /* defaults will be set by vu_send_reply() */
250 vmsg->size = sizeof(vmsg->payload.u64);
251 vmsg->payload.u64 = val;
252 vmsg->fd_num = 0;
253 }
254
255 /* A test to see if we have userfault available */
256 static bool
257 have_userfault(void)
258 {
259 #if defined(__linux__) && defined(__NR_userfaultfd) &&\
260 defined(UFFD_FEATURE_MISSING_SHMEM) &&\
261 defined(UFFD_FEATURE_MISSING_HUGETLBFS)
262 /* Now test the kernel we're running on really has the features */
263 int ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
264 struct uffdio_api api_struct;
265 if (ufd < 0) {
266 return false;
267 }
268
269 api_struct.api = UFFD_API;
270 api_struct.features = UFFD_FEATURE_MISSING_SHMEM |
271 UFFD_FEATURE_MISSING_HUGETLBFS;
272 if (ioctl(ufd, UFFDIO_API, &api_struct)) {
273 close(ufd);
274 return false;
275 }
276 close(ufd);
277 return true;
278
279 #else
280 return false;
281 #endif
282 }
283
284 static bool
285 vu_message_read_default(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
286 {
287 char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
288 struct iovec iov = {
289 .iov_base = (char *)vmsg,
290 .iov_len = VHOST_USER_HDR_SIZE,
291 };
292 struct msghdr msg = {
293 .msg_iov = &iov,
294 .msg_iovlen = 1,
295 .msg_control = control,
296 .msg_controllen = sizeof(control),
297 };
298 size_t fd_size;
299 struct cmsghdr *cmsg;
300 int rc;
301
302 do {
303 rc = recvmsg(conn_fd, &msg, 0);
304 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
305
306 if (rc < 0) {
307 vu_panic(dev, "Error while recvmsg: %s", strerror(errno));
308 return false;
309 }
310
311 vmsg->fd_num = 0;
312 for (cmsg = CMSG_FIRSTHDR(&msg);
313 cmsg != NULL;
314 cmsg = CMSG_NXTHDR(&msg, cmsg))
315 {
316 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
317 fd_size = cmsg->cmsg_len - CMSG_LEN(0);
318 vmsg->fd_num = fd_size / sizeof(int);
319 memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
320 break;
321 }
322 }
323
324 if (vmsg->size > sizeof(vmsg->payload)) {
325 vu_panic(dev,
326 "Error: too big message request: %d, size: vmsg->size: %u, "
327 "while sizeof(vmsg->payload) = %zu\n",
328 vmsg->request, vmsg->size, sizeof(vmsg->payload));
329 goto fail;
330 }
331
332 if (vmsg->size) {
333 do {
334 rc = read(conn_fd, &vmsg->payload, vmsg->size);
335 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
336
337 if (rc <= 0) {
338 vu_panic(dev, "Error while reading: %s", strerror(errno));
339 goto fail;
340 }
341
342 assert((uint32_t)rc == vmsg->size);
343 }
344
345 return true;
346
347 fail:
348 vmsg_close_fds(vmsg);
349
350 return false;
351 }
352
353 static bool
354 vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
355 {
356 int rc;
357 uint8_t *p = (uint8_t *)vmsg;
358 char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
359 struct iovec iov = {
360 .iov_base = (char *)vmsg,
361 .iov_len = VHOST_USER_HDR_SIZE,
362 };
363 struct msghdr msg = {
364 .msg_iov = &iov,
365 .msg_iovlen = 1,
366 .msg_control = control,
367 };
368 struct cmsghdr *cmsg;
369
370 memset(control, 0, sizeof(control));
371 assert(vmsg->fd_num <= VHOST_MEMORY_BASELINE_NREGIONS);
372 if (vmsg->fd_num > 0) {
373 size_t fdsize = vmsg->fd_num * sizeof(int);
374 msg.msg_controllen = CMSG_SPACE(fdsize);
375 cmsg = CMSG_FIRSTHDR(&msg);
376 cmsg->cmsg_len = CMSG_LEN(fdsize);
377 cmsg->cmsg_level = SOL_SOCKET;
378 cmsg->cmsg_type = SCM_RIGHTS;
379 memcpy(CMSG_DATA(cmsg), vmsg->fds, fdsize);
380 } else {
381 msg.msg_controllen = 0;
382 }
383
384 do {
385 rc = sendmsg(conn_fd, &msg, 0);
386 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
387
388 if (vmsg->size) {
389 do {
390 if (vmsg->data) {
391 rc = write(conn_fd, vmsg->data, vmsg->size);
392 } else {
393 rc = write(conn_fd, p + VHOST_USER_HDR_SIZE, vmsg->size);
394 }
395 } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
396 }
397
398 if (rc <= 0) {
399 vu_panic(dev, "Error while writing: %s", strerror(errno));
400 return false;
401 }
402
403 return true;
404 }
405
406 static bool
407 vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
408 {
409 /* Set the version in the flags when sending the reply */
410 vmsg->flags &= ~VHOST_USER_VERSION_MASK;
411 vmsg->flags |= VHOST_USER_VERSION;
412 vmsg->flags |= VHOST_USER_REPLY_MASK;
413
414 return vu_message_write(dev, conn_fd, vmsg);
415 }
416
417 /*
418 * Processes a reply on the slave channel.
419 * Entered with slave_mutex held and releases it before exit.
420 * Returns true on success.
421 */
422 static bool
423 vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
424 {
425 VhostUserMsg msg_reply;
426 bool result = false;
427
428 if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
429 result = true;
430 goto out;
431 }
432
433 if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
434 goto out;
435 }
436
437 if (msg_reply.request != vmsg->request) {
438 DPRINT("Received unexpected msg type. Expected %d received %d",
439 vmsg->request, msg_reply.request);
440 goto out;
441 }
442
443 result = msg_reply.payload.u64 == 0;
444
445 out:
446 pthread_mutex_unlock(&dev->slave_mutex);
447 return result;
448 }
449
450 /* Kick the log_call_fd if required. */
451 static void
452 vu_log_kick(VuDev *dev)
453 {
454 if (dev->log_call_fd != -1) {
455 DPRINT("Kicking the QEMU's log...\n");
456 if (eventfd_write(dev->log_call_fd, 1) < 0) {
457 vu_panic(dev, "Error writing eventfd: %s", strerror(errno));
458 }
459 }
460 }
461
462 static void
463 vu_log_page(uint8_t *log_table, uint64_t page)
464 {
465 DPRINT("Logged dirty guest page: %"PRId64"\n", page);
466 qatomic_or(&log_table[page / 8], 1 << (page % 8));
467 }
468
469 static void
470 vu_log_write(VuDev *dev, uint64_t address, uint64_t length)
471 {
472 uint64_t page;
473
474 if (!(dev->features & (1ULL << VHOST_F_LOG_ALL)) ||
475 !dev->log_table || !length) {
476 return;
477 }
478
479 assert(dev->log_size > ((address + length - 1) / VHOST_LOG_PAGE / 8));
480
481 page = address / VHOST_LOG_PAGE;
482 while (page * VHOST_LOG_PAGE < address + length) {
483 vu_log_page(dev->log_table, page);
484 page += 1;
485 }
486
487 vu_log_kick(dev);
488 }
489
490 static void
491 vu_kick_cb(VuDev *dev, int condition, void *data)
492 {
493 int index = (intptr_t)data;
494 VuVirtq *vq = &dev->vq[index];
495 int sock = vq->kick_fd;
496 eventfd_t kick_data;
497 ssize_t rc;
498
499 rc = eventfd_read(sock, &kick_data);
500 if (rc == -1) {
501 vu_panic(dev, "kick eventfd_read(): %s", strerror(errno));
502 dev->remove_watch(dev, dev->vq[index].kick_fd);
503 } else {
504 DPRINT("Got kick_data: %016"PRIx64" handler:%p idx:%d\n",
505 kick_data, vq->handler, index);
506 if (vq->handler) {
507 vq->handler(dev, index);
508 }
509 }
510 }
511
512 static bool
513 vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg)
514 {
515 vmsg->payload.u64 =
516 /*
517 * The following VIRTIO feature bits are supported by our virtqueue
518 * implementation:
519 */
520 1ULL << VIRTIO_F_NOTIFY_ON_EMPTY |
521 1ULL << VIRTIO_RING_F_INDIRECT_DESC |
522 1ULL << VIRTIO_RING_F_EVENT_IDX |
523 1ULL << VIRTIO_F_VERSION_1 |
524
525 /* vhost-user feature bits */
526 1ULL << VHOST_F_LOG_ALL |
527 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
528
529 if (dev->iface->get_features) {
530 vmsg->payload.u64 |= dev->iface->get_features(dev);
531 }
532
533 vmsg->size = sizeof(vmsg->payload.u64);
534 vmsg->fd_num = 0;
535
536 DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
537
538 return true;
539 }
540
541 static void
542 vu_set_enable_all_rings(VuDev *dev, bool enabled)
543 {
544 uint16_t i;
545
546 for (i = 0; i < dev->max_queues; i++) {
547 dev->vq[i].enable = enabled;
548 }
549 }
550
551 static bool
552 vu_set_features_exec(VuDev *dev, VhostUserMsg *vmsg)
553 {
554 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
555
556 dev->features = vmsg->payload.u64;
557 if (!vu_has_feature(dev, VIRTIO_F_VERSION_1)) {
558 /*
559 * We only support devices conforming to VIRTIO 1.0 or
560 * later
561 */
562 vu_panic(dev, "virtio legacy devices aren't supported by libvhost-user");
563 return false;
564 }
565
566 if (!(dev->features & VHOST_USER_F_PROTOCOL_FEATURES)) {
567 vu_set_enable_all_rings(dev, true);
568 }
569
570 if (dev->iface->set_features) {
571 dev->iface->set_features(dev, dev->features);
572 }
573
574 return false;
575 }
576
577 static bool
578 vu_set_owner_exec(VuDev *dev, VhostUserMsg *vmsg)
579 {
580 return false;
581 }
582
583 static void
584 vu_close_log(VuDev *dev)
585 {
586 if (dev->log_table) {
587 if (munmap(dev->log_table, dev->log_size) != 0) {
588 perror("close log munmap() error");
589 }
590
591 dev->log_table = NULL;
592 }
593 if (dev->log_call_fd != -1) {
594 close(dev->log_call_fd);
595 dev->log_call_fd = -1;
596 }
597 }
598
599 static bool
600 vu_reset_device_exec(VuDev *dev, VhostUserMsg *vmsg)
601 {
602 vu_set_enable_all_rings(dev, false);
603
604 return false;
605 }
606
607 static bool
608 map_ring(VuDev *dev, VuVirtq *vq)
609 {
610 vq->vring.desc = qva_to_va(dev, vq->vra.desc_user_addr);
611 vq->vring.used = qva_to_va(dev, vq->vra.used_user_addr);
612 vq->vring.avail = qva_to_va(dev, vq->vra.avail_user_addr);
613
614 DPRINT("Setting virtq addresses:\n");
615 DPRINT(" vring_desc at %p\n", vq->vring.desc);
616 DPRINT(" vring_used at %p\n", vq->vring.used);
617 DPRINT(" vring_avail at %p\n", vq->vring.avail);
618
619 return !(vq->vring.desc && vq->vring.used && vq->vring.avail);
620 }
621
622 static bool
623 generate_faults(VuDev *dev) {
624 unsigned int i;
625 for (i = 0; i < dev->nregions; i++) {
626 VuDevRegion *dev_region = &dev->regions[i];
627 int ret;
628 #ifdef UFFDIO_REGISTER
629 struct uffdio_register reg_struct;
630
631 /*
632 * We should already have an open ufd. Mark each memory
633 * range as ufd.
634 * Discard any mapping we have here; note I can't use MADV_REMOVE
635 * or fallocate to make the hole since I don't want to lose
636 * data that's already arrived in the shared process.
637 * TODO: How to do hugepage
638 */
639 ret = madvise((void *)(uintptr_t)dev_region->mmap_addr,
640 dev_region->size + dev_region->mmap_offset,
641 MADV_DONTNEED);
642 if (ret) {
643 fprintf(stderr,
644 "%s: Failed to madvise(DONTNEED) region %d: %s\n",
645 __func__, i, strerror(errno));
646 }
647 /*
648 * Turn off transparent hugepages so we dont get lose wakeups
649 * in neighbouring pages.
650 * TODO: Turn this backon later.
651 */
652 ret = madvise((void *)(uintptr_t)dev_region->mmap_addr,
653 dev_region->size + dev_region->mmap_offset,
654 MADV_NOHUGEPAGE);
655 if (ret) {
656 /*
657 * Note: This can happen legally on kernels that are configured
658 * without madvise'able hugepages
659 */
660 fprintf(stderr,
661 "%s: Failed to madvise(NOHUGEPAGE) region %d: %s\n",
662 __func__, i, strerror(errno));
663 }
664
665 reg_struct.range.start = (uintptr_t)dev_region->mmap_addr;
666 reg_struct.range.len = dev_region->size + dev_region->mmap_offset;
667 reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
668
669 if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER, &reg_struct)) {
670 vu_panic(dev, "%s: Failed to userfault region %d "
671 "@%" PRIx64 " + size:%" PRIx64 " offset: %" PRIx64
672 ": (ufd=%d)%s\n",
673 __func__, i,
674 dev_region->mmap_addr,
675 dev_region->size, dev_region->mmap_offset,
676 dev->postcopy_ufd, strerror(errno));
677 return false;
678 }
679 if (!(reg_struct.ioctls & ((__u64)1 << _UFFDIO_COPY))) {
680 vu_panic(dev, "%s Region (%d) doesn't support COPY",
681 __func__, i);
682 return false;
683 }
684 DPRINT("%s: region %d: Registered userfault for %"
685 PRIx64 " + %" PRIx64 "\n", __func__, i,
686 (uint64_t)reg_struct.range.start,
687 (uint64_t)reg_struct.range.len);
688 /* Now it's registered we can let the client at it */
689 if (mprotect((void *)(uintptr_t)dev_region->mmap_addr,
690 dev_region->size + dev_region->mmap_offset,
691 PROT_READ | PROT_WRITE)) {
692 vu_panic(dev, "failed to mprotect region %d for postcopy (%s)",
693 i, strerror(errno));
694 return false;
695 }
696 /* TODO: Stash 'zero' support flags somewhere */
697 #endif
698 }
699
700 return true;
701 }
702
703 static bool
704 vu_add_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
705 int i;
706 bool track_ramblocks = dev->postcopy_listening;
707 VhostUserMemoryRegion m = vmsg->payload.memreg.region, *msg_region = &m;
708 VuDevRegion *dev_region = &dev->regions[dev->nregions];
709 void *mmap_addr;
710
711 if (vmsg->fd_num != 1) {
712 vmsg_close_fds(vmsg);
713 vu_panic(dev, "VHOST_USER_ADD_MEM_REG received %d fds - only 1 fd "
714 "should be sent for this message type", vmsg->fd_num);
715 return false;
716 }
717
718 if (vmsg->size < VHOST_USER_MEM_REG_SIZE) {
719 close(vmsg->fds[0]);
720 vu_panic(dev, "VHOST_USER_ADD_MEM_REG requires a message size of at "
721 "least %zu bytes and only %d bytes were received",
722 VHOST_USER_MEM_REG_SIZE, vmsg->size);
723 return false;
724 }
725
726 if (dev->nregions == VHOST_USER_MAX_RAM_SLOTS) {
727 close(vmsg->fds[0]);
728 vu_panic(dev, "failing attempt to hot add memory via "
729 "VHOST_USER_ADD_MEM_REG message because the backend has "
730 "no free ram slots available");
731 return false;
732 }
733
734 /*
735 * If we are in postcopy mode and we receive a u64 payload with a 0 value
736 * we know all the postcopy client bases have been received, and we
737 * should start generating faults.
738 */
739 if (track_ramblocks &&
740 vmsg->size == sizeof(vmsg->payload.u64) &&
741 vmsg->payload.u64 == 0) {
742 (void)generate_faults(dev);
743 return false;
744 }
745
746 DPRINT("Adding region: %u\n", dev->nregions);
747 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
748 msg_region->guest_phys_addr);
749 DPRINT(" memory_size: 0x%016"PRIx64"\n",
750 msg_region->memory_size);
751 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
752 msg_region->userspace_addr);
753 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
754 msg_region->mmap_offset);
755
756 dev_region->gpa = msg_region->guest_phys_addr;
757 dev_region->size = msg_region->memory_size;
758 dev_region->qva = msg_region->userspace_addr;
759 dev_region->mmap_offset = msg_region->mmap_offset;
760
761 /*
762 * We don't use offset argument of mmap() since the
763 * mapped address has to be page aligned, and we use huge
764 * pages.
765 */
766 if (track_ramblocks) {
767 /*
768 * In postcopy we're using PROT_NONE here to catch anyone
769 * accessing it before we userfault.
770 */
771 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
772 PROT_NONE, MAP_SHARED | MAP_NORESERVE,
773 vmsg->fds[0], 0);
774 } else {
775 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
776 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE,
777 vmsg->fds[0], 0);
778 }
779
780 if (mmap_addr == MAP_FAILED) {
781 vu_panic(dev, "region mmap error: %s", strerror(errno));
782 } else {
783 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
784 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
785 dev_region->mmap_addr);
786 }
787
788 close(vmsg->fds[0]);
789
790 if (track_ramblocks) {
791 /*
792 * Return the address to QEMU so that it can translate the ufd
793 * fault addresses back.
794 */
795 msg_region->userspace_addr = (uintptr_t)(mmap_addr +
796 dev_region->mmap_offset);
797
798 /* Send the message back to qemu with the addresses filled in. */
799 vmsg->fd_num = 0;
800 DPRINT("Successfully added new region in postcopy\n");
801 dev->nregions++;
802 return true;
803 } else {
804 for (i = 0; i < dev->max_queues; i++) {
805 if (dev->vq[i].vring.desc) {
806 if (map_ring(dev, &dev->vq[i])) {
807 vu_panic(dev, "remapping queue %d for new memory region",
808 i);
809 }
810 }
811 }
812
813 DPRINT("Successfully added new region\n");
814 dev->nregions++;
815 return false;
816 }
817 }
818
819 static inline bool reg_equal(VuDevRegion *vudev_reg,
820 VhostUserMemoryRegion *msg_reg)
821 {
822 if (vudev_reg->gpa == msg_reg->guest_phys_addr &&
823 vudev_reg->qva == msg_reg->userspace_addr &&
824 vudev_reg->size == msg_reg->memory_size) {
825 return true;
826 }
827
828 return false;
829 }
830
831 static bool
832 vu_rem_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
833 VhostUserMemoryRegion m = vmsg->payload.memreg.region, *msg_region = &m;
834 unsigned int i;
835 bool found = false;
836
837 if (vmsg->fd_num > 1) {
838 vmsg_close_fds(vmsg);
839 vu_panic(dev, "VHOST_USER_REM_MEM_REG received %d fds - at most 1 fd "
840 "should be sent for this message type", vmsg->fd_num);
841 return false;
842 }
843
844 if (vmsg->size < VHOST_USER_MEM_REG_SIZE) {
845 vmsg_close_fds(vmsg);
846 vu_panic(dev, "VHOST_USER_REM_MEM_REG requires a message size of at "
847 "least %zu bytes and only %d bytes were received",
848 VHOST_USER_MEM_REG_SIZE, vmsg->size);
849 return false;
850 }
851
852 DPRINT("Removing region:\n");
853 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
854 msg_region->guest_phys_addr);
855 DPRINT(" memory_size: 0x%016"PRIx64"\n",
856 msg_region->memory_size);
857 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
858 msg_region->userspace_addr);
859 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
860 msg_region->mmap_offset);
861
862 for (i = 0; i < dev->nregions; i++) {
863 if (reg_equal(&dev->regions[i], msg_region)) {
864 VuDevRegion *r = &dev->regions[i];
865 void *m = (void *) (uintptr_t) r->mmap_addr;
866
867 if (m) {
868 munmap(m, r->size + r->mmap_offset);
869 }
870
871 /*
872 * Shift all affected entries by 1 to close the hole at index i and
873 * zero out the last entry.
874 */
875 memmove(dev->regions + i, dev->regions + i + 1,
876 sizeof(VuDevRegion) * (dev->nregions - i - 1));
877 memset(dev->regions + dev->nregions - 1, 0, sizeof(VuDevRegion));
878 DPRINT("Successfully removed a region\n");
879 dev->nregions--;
880 i--;
881
882 found = true;
883
884 /* Continue the search for eventual duplicates. */
885 }
886 }
887
888 if (!found) {
889 vu_panic(dev, "Specified region not found\n");
890 }
891
892 vmsg_close_fds(vmsg);
893
894 return false;
895 }
896
897 static bool
898 vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
899 {
900 unsigned int i;
901 VhostUserMemory m = vmsg->payload.memory, *memory = &m;
902 dev->nregions = memory->nregions;
903
904 DPRINT("Nregions: %u\n", memory->nregions);
905 for (i = 0; i < dev->nregions; i++) {
906 void *mmap_addr;
907 VhostUserMemoryRegion *msg_region = &memory->regions[i];
908 VuDevRegion *dev_region = &dev->regions[i];
909
910 DPRINT("Region %d\n", i);
911 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
912 msg_region->guest_phys_addr);
913 DPRINT(" memory_size: 0x%016"PRIx64"\n",
914 msg_region->memory_size);
915 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
916 msg_region->userspace_addr);
917 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
918 msg_region->mmap_offset);
919
920 dev_region->gpa = msg_region->guest_phys_addr;
921 dev_region->size = msg_region->memory_size;
922 dev_region->qva = msg_region->userspace_addr;
923 dev_region->mmap_offset = msg_region->mmap_offset;
924
925 /* We don't use offset argument of mmap() since the
926 * mapped address has to be page aligned, and we use huge
927 * pages.
928 * In postcopy we're using PROT_NONE here to catch anyone
929 * accessing it before we userfault
930 */
931 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
932 PROT_NONE, MAP_SHARED | MAP_NORESERVE,
933 vmsg->fds[i], 0);
934
935 if (mmap_addr == MAP_FAILED) {
936 vu_panic(dev, "region mmap error: %s", strerror(errno));
937 } else {
938 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
939 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
940 dev_region->mmap_addr);
941 }
942
943 /* Return the address to QEMU so that it can translate the ufd
944 * fault addresses back.
945 */
946 msg_region->userspace_addr = (uintptr_t)(mmap_addr +
947 dev_region->mmap_offset);
948 close(vmsg->fds[i]);
949 }
950
951 /* Send the message back to qemu with the addresses filled in */
952 vmsg->fd_num = 0;
953 if (!vu_send_reply(dev, dev->sock, vmsg)) {
954 vu_panic(dev, "failed to respond to set-mem-table for postcopy");
955 return false;
956 }
957
958 /* Wait for QEMU to confirm that it's registered the handler for the
959 * faults.
960 */
961 if (!dev->read_msg(dev, dev->sock, vmsg) ||
962 vmsg->size != sizeof(vmsg->payload.u64) ||
963 vmsg->payload.u64 != 0) {
964 vu_panic(dev, "failed to receive valid ack for postcopy set-mem-table");
965 return false;
966 }
967
968 /* OK, now we can go and register the memory and generate faults */
969 (void)generate_faults(dev);
970
971 return false;
972 }
973
974 static bool
975 vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg)
976 {
977 unsigned int i;
978 VhostUserMemory m = vmsg->payload.memory, *memory = &m;
979
980 for (i = 0; i < dev->nregions; i++) {
981 VuDevRegion *r = &dev->regions[i];
982 void *m = (void *) (uintptr_t) r->mmap_addr;
983
984 if (m) {
985 munmap(m, r->size + r->mmap_offset);
986 }
987 }
988 dev->nregions = memory->nregions;
989
990 if (dev->postcopy_listening) {
991 return vu_set_mem_table_exec_postcopy(dev, vmsg);
992 }
993
994 DPRINT("Nregions: %u\n", memory->nregions);
995 for (i = 0; i < dev->nregions; i++) {
996 void *mmap_addr;
997 VhostUserMemoryRegion *msg_region = &memory->regions[i];
998 VuDevRegion *dev_region = &dev->regions[i];
999
1000 DPRINT("Region %d\n", i);
1001 DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n",
1002 msg_region->guest_phys_addr);
1003 DPRINT(" memory_size: 0x%016"PRIx64"\n",
1004 msg_region->memory_size);
1005 DPRINT(" userspace_addr 0x%016"PRIx64"\n",
1006 msg_region->userspace_addr);
1007 DPRINT(" mmap_offset 0x%016"PRIx64"\n",
1008 msg_region->mmap_offset);
1009
1010 dev_region->gpa = msg_region->guest_phys_addr;
1011 dev_region->size = msg_region->memory_size;
1012 dev_region->qva = msg_region->userspace_addr;
1013 dev_region->mmap_offset = msg_region->mmap_offset;
1014
1015 /* We don't use offset argument of mmap() since the
1016 * mapped address has to be page aligned, and we use huge
1017 * pages. */
1018 mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
1019 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE,
1020 vmsg->fds[i], 0);
1021
1022 if (mmap_addr == MAP_FAILED) {
1023 vu_panic(dev, "region mmap error: %s", strerror(errno));
1024 } else {
1025 dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
1026 DPRINT(" mmap_addr: 0x%016"PRIx64"\n",
1027 dev_region->mmap_addr);
1028 }
1029
1030 close(vmsg->fds[i]);
1031 }
1032
1033 for (i = 0; i < dev->max_queues; i++) {
1034 if (dev->vq[i].vring.desc) {
1035 if (map_ring(dev, &dev->vq[i])) {
1036 vu_panic(dev, "remapping queue %d during setmemtable", i);
1037 }
1038 }
1039 }
1040
1041 return false;
1042 }
1043
1044 static bool
1045 vu_set_log_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1046 {
1047 int fd;
1048 uint64_t log_mmap_size, log_mmap_offset;
1049 void *rc;
1050
1051 if (vmsg->fd_num != 1 ||
1052 vmsg->size != sizeof(vmsg->payload.log)) {
1053 vu_panic(dev, "Invalid log_base message");
1054 return true;
1055 }
1056
1057 fd = vmsg->fds[0];
1058 log_mmap_offset = vmsg->payload.log.mmap_offset;
1059 log_mmap_size = vmsg->payload.log.mmap_size;
1060 DPRINT("Log mmap_offset: %"PRId64"\n", log_mmap_offset);
1061 DPRINT("Log mmap_size: %"PRId64"\n", log_mmap_size);
1062
1063 rc = mmap(0, log_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
1064 log_mmap_offset);
1065 close(fd);
1066 if (rc == MAP_FAILED) {
1067 perror("log mmap error");
1068 }
1069
1070 if (dev->log_table) {
1071 munmap(dev->log_table, dev->log_size);
1072 }
1073 dev->log_table = rc;
1074 dev->log_size = log_mmap_size;
1075
1076 vmsg->size = sizeof(vmsg->payload.u64);
1077 vmsg->fd_num = 0;
1078
1079 return true;
1080 }
1081
1082 static bool
1083 vu_set_log_fd_exec(VuDev *dev, VhostUserMsg *vmsg)
1084 {
1085 if (vmsg->fd_num != 1) {
1086 vu_panic(dev, "Invalid log_fd message");
1087 return false;
1088 }
1089
1090 if (dev->log_call_fd != -1) {
1091 close(dev->log_call_fd);
1092 }
1093 dev->log_call_fd = vmsg->fds[0];
1094 DPRINT("Got log_call_fd: %d\n", vmsg->fds[0]);
1095
1096 return false;
1097 }
1098
1099 static bool
1100 vu_set_vring_num_exec(VuDev *dev, VhostUserMsg *vmsg)
1101 {
1102 unsigned int index = vmsg->payload.state.index;
1103 unsigned int num = vmsg->payload.state.num;
1104
1105 DPRINT("State.index: %u\n", index);
1106 DPRINT("State.num: %u\n", num);
1107 dev->vq[index].vring.num = num;
1108
1109 return false;
1110 }
1111
1112 static bool
1113 vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg)
1114 {
1115 struct vhost_vring_addr addr = vmsg->payload.addr, *vra = &addr;
1116 unsigned int index = vra->index;
1117 VuVirtq *vq = &dev->vq[index];
1118
1119 DPRINT("vhost_vring_addr:\n");
1120 DPRINT(" index: %d\n", vra->index);
1121 DPRINT(" flags: %d\n", vra->flags);
1122 DPRINT(" desc_user_addr: 0x%016" PRIx64 "\n", (uint64_t)vra->desc_user_addr);
1123 DPRINT(" used_user_addr: 0x%016" PRIx64 "\n", (uint64_t)vra->used_user_addr);
1124 DPRINT(" avail_user_addr: 0x%016" PRIx64 "\n", (uint64_t)vra->avail_user_addr);
1125 DPRINT(" log_guest_addr: 0x%016" PRIx64 "\n", (uint64_t)vra->log_guest_addr);
1126
1127 vq->vra = *vra;
1128 vq->vring.flags = vra->flags;
1129 vq->vring.log_guest_addr = vra->log_guest_addr;
1130
1131
1132 if (map_ring(dev, vq)) {
1133 vu_panic(dev, "Invalid vring_addr message");
1134 return false;
1135 }
1136
1137 vq->used_idx = le16toh(vq->vring.used->idx);
1138
1139 if (vq->last_avail_idx != vq->used_idx) {
1140 bool resume = dev->iface->queue_is_processed_in_order &&
1141 dev->iface->queue_is_processed_in_order(dev, index);
1142
1143 DPRINT("Last avail index != used index: %u != %u%s\n",
1144 vq->last_avail_idx, vq->used_idx,
1145 resume ? ", resuming" : "");
1146
1147 if (resume) {
1148 vq->shadow_avail_idx = vq->last_avail_idx = vq->used_idx;
1149 }
1150 }
1151
1152 return false;
1153 }
1154
1155 static bool
1156 vu_set_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1157 {
1158 unsigned int index = vmsg->payload.state.index;
1159 unsigned int num = vmsg->payload.state.num;
1160
1161 DPRINT("State.index: %u\n", index);
1162 DPRINT("State.num: %u\n", num);
1163 dev->vq[index].shadow_avail_idx = dev->vq[index].last_avail_idx = num;
1164
1165 return false;
1166 }
1167
1168 static bool
1169 vu_get_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
1170 {
1171 unsigned int index = vmsg->payload.state.index;
1172
1173 DPRINT("State.index: %u\n", index);
1174 vmsg->payload.state.num = dev->vq[index].last_avail_idx;
1175 vmsg->size = sizeof(vmsg->payload.state);
1176
1177 dev->vq[index].started = false;
1178 if (dev->iface->queue_set_started) {
1179 dev->iface->queue_set_started(dev, index, false);
1180 }
1181
1182 if (dev->vq[index].call_fd != -1) {
1183 close(dev->vq[index].call_fd);
1184 dev->vq[index].call_fd = -1;
1185 }
1186 if (dev->vq[index].kick_fd != -1) {
1187 dev->remove_watch(dev, dev->vq[index].kick_fd);
1188 close(dev->vq[index].kick_fd);
1189 dev->vq[index].kick_fd = -1;
1190 }
1191
1192 return true;
1193 }
1194
1195 static bool
1196 vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
1197 {
1198 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1199 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1200
1201 if (index >= dev->max_queues) {
1202 vmsg_close_fds(vmsg);
1203 vu_panic(dev, "Invalid queue index: %u", index);
1204 return false;
1205 }
1206
1207 if (nofd) {
1208 vmsg_close_fds(vmsg);
1209 return true;
1210 }
1211
1212 if (vmsg->fd_num != 1) {
1213 vmsg_close_fds(vmsg);
1214 vu_panic(dev, "Invalid fds in request: %d", vmsg->request);
1215 return false;
1216 }
1217
1218 return true;
1219 }
1220
1221 static int
1222 inflight_desc_compare(const void *a, const void *b)
1223 {
1224 VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
1225 *desc1 = (VuVirtqInflightDesc *)b;
1226
1227 if (desc1->counter > desc0->counter &&
1228 (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
1229 return 1;
1230 }
1231
1232 return -1;
1233 }
1234
1235 static int
1236 vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
1237 {
1238 int i = 0;
1239
1240 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
1241 return 0;
1242 }
1243
1244 if (unlikely(!vq->inflight)) {
1245 return -1;
1246 }
1247
1248 if (unlikely(!vq->inflight->version)) {
1249 /* initialize the buffer */
1250 vq->inflight->version = INFLIGHT_VERSION;
1251 return 0;
1252 }
1253
1254 vq->used_idx = le16toh(vq->vring.used->idx);
1255 vq->resubmit_num = 0;
1256 vq->resubmit_list = NULL;
1257 vq->counter = 0;
1258
1259 if (unlikely(vq->inflight->used_idx != vq->used_idx)) {
1260 vq->inflight->desc[vq->inflight->last_batch_head].inflight = 0;
1261
1262 barrier();
1263
1264 vq->inflight->used_idx = vq->used_idx;
1265 }
1266
1267 for (i = 0; i < vq->inflight->desc_num; i++) {
1268 if (vq->inflight->desc[i].inflight == 1) {
1269 vq->inuse++;
1270 }
1271 }
1272
1273 vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
1274
1275 if (vq->inuse) {
1276 vq->resubmit_list = calloc(vq->inuse, sizeof(VuVirtqInflightDesc));
1277 if (!vq->resubmit_list) {
1278 return -1;
1279 }
1280
1281 for (i = 0; i < vq->inflight->desc_num; i++) {
1282 if (vq->inflight->desc[i].inflight) {
1283 vq->resubmit_list[vq->resubmit_num].index = i;
1284 vq->resubmit_list[vq->resubmit_num].counter =
1285 vq->inflight->desc[i].counter;
1286 vq->resubmit_num++;
1287 }
1288 }
1289
1290 if (vq->resubmit_num > 1) {
1291 qsort(vq->resubmit_list, vq->resubmit_num,
1292 sizeof(VuVirtqInflightDesc), inflight_desc_compare);
1293 }
1294 vq->counter = vq->resubmit_list[0].counter + 1;
1295 }
1296
1297 /* in case of I/O hang after reconnecting */
1298 if (eventfd_write(vq->kick_fd, 1)) {
1299 return -1;
1300 }
1301
1302 return 0;
1303 }
1304
1305 static bool
1306 vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
1307 {
1308 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1309 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1310
1311 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1312
1313 if (!vu_check_queue_msg_file(dev, vmsg)) {
1314 return false;
1315 }
1316
1317 if (dev->vq[index].kick_fd != -1) {
1318 dev->remove_watch(dev, dev->vq[index].kick_fd);
1319 close(dev->vq[index].kick_fd);
1320 dev->vq[index].kick_fd = -1;
1321 }
1322
1323 dev->vq[index].kick_fd = nofd ? -1 : vmsg->fds[0];
1324 DPRINT("Got kick_fd: %d for vq: %d\n", dev->vq[index].kick_fd, index);
1325
1326 dev->vq[index].started = true;
1327 if (dev->iface->queue_set_started) {
1328 dev->iface->queue_set_started(dev, index, true);
1329 }
1330
1331 if (dev->vq[index].kick_fd != -1 && dev->vq[index].handler) {
1332 dev->set_watch(dev, dev->vq[index].kick_fd, VU_WATCH_IN,
1333 vu_kick_cb, (void *)(long)index);
1334
1335 DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
1336 dev->vq[index].kick_fd, index);
1337 }
1338
1339 if (vu_check_queue_inflights(dev, &dev->vq[index])) {
1340 vu_panic(dev, "Failed to check inflights for vq: %d\n", index);
1341 }
1342
1343 return false;
1344 }
1345
1346 void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
1347 vu_queue_handler_cb handler)
1348 {
1349 int qidx = vq - dev->vq;
1350
1351 vq->handler = handler;
1352 if (vq->kick_fd >= 0) {
1353 if (handler) {
1354 dev->set_watch(dev, vq->kick_fd, VU_WATCH_IN,
1355 vu_kick_cb, (void *)(long)qidx);
1356 } else {
1357 dev->remove_watch(dev, vq->kick_fd);
1358 }
1359 }
1360 }
1361
1362 bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
1363 int size, int offset)
1364 {
1365 int qidx = vq - dev->vq;
1366 int fd_num = 0;
1367 VhostUserMsg vmsg = {
1368 .request = VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG,
1369 .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1370 .size = sizeof(vmsg.payload.area),
1371 .payload.area = {
1372 .u64 = qidx & VHOST_USER_VRING_IDX_MASK,
1373 .size = size,
1374 .offset = offset,
1375 },
1376 };
1377
1378 if (fd == -1) {
1379 vmsg.payload.area.u64 |= VHOST_USER_VRING_NOFD_MASK;
1380 } else {
1381 vmsg.fds[fd_num++] = fd;
1382 }
1383
1384 vmsg.fd_num = fd_num;
1385
1386 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD)) {
1387 return false;
1388 }
1389
1390 pthread_mutex_lock(&dev->slave_mutex);
1391 if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {
1392 pthread_mutex_unlock(&dev->slave_mutex);
1393 return false;
1394 }
1395
1396 /* Also unlocks the slave_mutex */
1397 return vu_process_message_reply(dev, &vmsg);
1398 }
1399
1400 static bool
1401 vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
1402 {
1403 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1404 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1405
1406 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1407
1408 if (!vu_check_queue_msg_file(dev, vmsg)) {
1409 return false;
1410 }
1411
1412 if (dev->vq[index].call_fd != -1) {
1413 close(dev->vq[index].call_fd);
1414 dev->vq[index].call_fd = -1;
1415 }
1416
1417 dev->vq[index].call_fd = nofd ? -1 : vmsg->fds[0];
1418
1419 /* in case of I/O hang after reconnecting */
1420 if (dev->vq[index].call_fd != -1 && eventfd_write(vmsg->fds[0], 1)) {
1421 return -1;
1422 }
1423
1424 DPRINT("Got call_fd: %d for vq: %d\n", dev->vq[index].call_fd, index);
1425
1426 return false;
1427 }
1428
1429 static bool
1430 vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg)
1431 {
1432 int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
1433 bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
1434
1435 DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1436
1437 if (!vu_check_queue_msg_file(dev, vmsg)) {
1438 return false;
1439 }
1440
1441 if (dev->vq[index].err_fd != -1) {
1442 close(dev->vq[index].err_fd);
1443 dev->vq[index].err_fd = -1;
1444 }
1445
1446 dev->vq[index].err_fd = nofd ? -1 : vmsg->fds[0];
1447
1448 return false;
1449 }
1450
1451 static bool
1452 vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
1453 {
1454 /*
1455 * Note that we support, but intentionally do not set,
1456 * VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS. This means that
1457 * a device implementation can return it in its callback
1458 * (get_protocol_features) if it wants to use this for
1459 * simulation, but it is otherwise not desirable (if even
1460 * implemented by the master.)
1461 */
1462 uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_MQ |
1463 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
1464 1ULL << VHOST_USER_PROTOCOL_F_BACKEND_REQ |
1465 1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER |
1466 1ULL << VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD |
1467 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |
1468 1ULL << VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS;
1469
1470 if (have_userfault()) {
1471 features |= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;
1472 }
1473
1474 if (dev->iface->get_config && dev->iface->set_config) {
1475 features |= 1ULL << VHOST_USER_PROTOCOL_F_CONFIG;
1476 }
1477
1478 if (dev->iface->get_protocol_features) {
1479 features |= dev->iface->get_protocol_features(dev);
1480 }
1481
1482 vmsg_set_reply_u64(vmsg, features);
1483 return true;
1484 }
1485
1486 static bool
1487 vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
1488 {
1489 uint64_t features = vmsg->payload.u64;
1490
1491 DPRINT("u64: 0x%016"PRIx64"\n", features);
1492
1493 dev->protocol_features = vmsg->payload.u64;
1494
1495 if (vu_has_protocol_feature(dev,
1496 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
1497 (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ) ||
1498 !vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1499 /*
1500 * The use case for using messages for kick/call is simulation, to make
1501 * the kick and call synchronous. To actually get that behaviour, both
1502 * of the other features are required.
1503 * Theoretically, one could use only kick messages, or do them without
1504 * having F_REPLY_ACK, but too many (possibly pending) messages on the
1505 * socket will eventually cause the master to hang, to avoid this in
1506 * scenarios where not desired enforce that the settings are in a way
1507 * that actually enables the simulation case.
1508 */
1509 vu_panic(dev,
1510 "F_IN_BAND_NOTIFICATIONS requires F_BACKEND_REQ && F_REPLY_ACK");
1511 return false;
1512 }
1513
1514 if (dev->iface->set_protocol_features) {
1515 dev->iface->set_protocol_features(dev, features);
1516 }
1517
1518 return false;
1519 }
1520
1521 static bool
1522 vu_get_queue_num_exec(VuDev *dev, VhostUserMsg *vmsg)
1523 {
1524 vmsg_set_reply_u64(vmsg, dev->max_queues);
1525 return true;
1526 }
1527
1528 static bool
1529 vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
1530 {
1531 unsigned int index = vmsg->payload.state.index;
1532 unsigned int enable = vmsg->payload.state.num;
1533
1534 DPRINT("State.index: %u\n", index);
1535 DPRINT("State.enable: %u\n", enable);
1536
1537 if (index >= dev->max_queues) {
1538 vu_panic(dev, "Invalid vring_enable index: %u", index);
1539 return false;
1540 }
1541
1542 dev->vq[index].enable = enable;
1543 return false;
1544 }
1545
1546 static bool
1547 vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
1548 {
1549 if (vmsg->fd_num != 1) {
1550 vu_panic(dev, "Invalid slave_req_fd message (%d fd's)", vmsg->fd_num);
1551 return false;
1552 }
1553
1554 if (dev->slave_fd != -1) {
1555 close(dev->slave_fd);
1556 }
1557 dev->slave_fd = vmsg->fds[0];
1558 DPRINT("Got slave_fd: %d\n", vmsg->fds[0]);
1559
1560 return false;
1561 }
1562
1563 static bool
1564 vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
1565 {
1566 int ret = -1;
1567
1568 if (dev->iface->get_config) {
1569 ret = dev->iface->get_config(dev, vmsg->payload.config.region,
1570 vmsg->payload.config.size);
1571 }
1572
1573 if (ret) {
1574 /* resize to zero to indicate an error to master */
1575 vmsg->size = 0;
1576 }
1577
1578 return true;
1579 }
1580
1581 static bool
1582 vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
1583 {
1584 int ret = -1;
1585
1586 if (dev->iface->set_config) {
1587 ret = dev->iface->set_config(dev, vmsg->payload.config.region,
1588 vmsg->payload.config.offset,
1589 vmsg->payload.config.size,
1590 vmsg->payload.config.flags);
1591 if (ret) {
1592 vu_panic(dev, "Set virtio configuration space failed");
1593 }
1594 }
1595
1596 return false;
1597 }
1598
1599 static bool
1600 vu_set_postcopy_advise(VuDev *dev, VhostUserMsg *vmsg)
1601 {
1602 #ifdef UFFDIO_API
1603 struct uffdio_api api_struct;
1604
1605 dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
1606 vmsg->size = 0;
1607 #else
1608 dev->postcopy_ufd = -1;
1609 #endif
1610
1611 if (dev->postcopy_ufd == -1) {
1612 vu_panic(dev, "Userfaultfd not available: %s", strerror(errno));
1613 goto out;
1614 }
1615
1616 #ifdef UFFDIO_API
1617 api_struct.api = UFFD_API;
1618 api_struct.features = 0;
1619 if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) {
1620 vu_panic(dev, "Failed UFFDIO_API: %s", strerror(errno));
1621 close(dev->postcopy_ufd);
1622 dev->postcopy_ufd = -1;
1623 goto out;
1624 }
1625 /* TODO: Stash feature flags somewhere */
1626 #endif
1627
1628 out:
1629 /* Return a ufd to the QEMU */
1630 vmsg->fd_num = 1;
1631 vmsg->fds[0] = dev->postcopy_ufd;
1632 return true; /* = send a reply */
1633 }
1634
1635 static bool
1636 vu_set_postcopy_listen(VuDev *dev, VhostUserMsg *vmsg)
1637 {
1638 if (dev->nregions) {
1639 vu_panic(dev, "Regions already registered at postcopy-listen");
1640 vmsg_set_reply_u64(vmsg, -1);
1641 return true;
1642 }
1643 dev->postcopy_listening = true;
1644
1645 vmsg_set_reply_u64(vmsg, 0);
1646 return true;
1647 }
1648
1649 static bool
1650 vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
1651 {
1652 DPRINT("%s: Entry\n", __func__);
1653 dev->postcopy_listening = false;
1654 if (dev->postcopy_ufd > 0) {
1655 close(dev->postcopy_ufd);
1656 dev->postcopy_ufd = -1;
1657 DPRINT("%s: Done close\n", __func__);
1658 }
1659
1660 vmsg_set_reply_u64(vmsg, 0);
1661 DPRINT("%s: exit\n", __func__);
1662 return true;
1663 }
1664
1665 static inline uint64_t
1666 vu_inflight_queue_size(uint16_t queue_size)
1667 {
1668 return ALIGN_UP(sizeof(VuDescStateSplit) * queue_size +
1669 sizeof(uint16_t), INFLIGHT_ALIGNMENT);
1670 }
1671
1672 #ifdef MFD_ALLOW_SEALING
1673 static void *
1674 memfd_alloc(const char *name, size_t size, unsigned int flags, int *fd)
1675 {
1676 void *ptr;
1677 int ret;
1678
1679 *fd = memfd_create(name, MFD_ALLOW_SEALING);
1680 if (*fd < 0) {
1681 return NULL;
1682 }
1683
1684 ret = ftruncate(*fd, size);
1685 if (ret < 0) {
1686 close(*fd);
1687 return NULL;
1688 }
1689
1690 ret = fcntl(*fd, F_ADD_SEALS, flags);
1691 if (ret < 0) {
1692 close(*fd);
1693 return NULL;
1694 }
1695
1696 ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, 0);
1697 if (ptr == MAP_FAILED) {
1698 close(*fd);
1699 return NULL;
1700 }
1701
1702 return ptr;
1703 }
1704 #endif
1705
1706 static bool
1707 vu_get_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
1708 {
1709 int fd = -1;
1710 void *addr = NULL;
1711 uint64_t mmap_size;
1712 uint16_t num_queues, queue_size;
1713
1714 if (vmsg->size != sizeof(vmsg->payload.inflight)) {
1715 vu_panic(dev, "Invalid get_inflight_fd message:%d", vmsg->size);
1716 vmsg->payload.inflight.mmap_size = 0;
1717 return true;
1718 }
1719
1720 num_queues = vmsg->payload.inflight.num_queues;
1721 queue_size = vmsg->payload.inflight.queue_size;
1722
1723 DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
1724 DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
1725
1726 mmap_size = vu_inflight_queue_size(queue_size) * num_queues;
1727
1728 #ifdef MFD_ALLOW_SEALING
1729 addr = memfd_alloc("vhost-inflight", mmap_size,
1730 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL,
1731 &fd);
1732 #else
1733 vu_panic(dev, "Not implemented: memfd support is missing");
1734 #endif
1735
1736 if (!addr) {
1737 vu_panic(dev, "Failed to alloc vhost inflight area");
1738 vmsg->payload.inflight.mmap_size = 0;
1739 return true;
1740 }
1741
1742 memset(addr, 0, mmap_size);
1743
1744 dev->inflight_info.addr = addr;
1745 dev->inflight_info.size = vmsg->payload.inflight.mmap_size = mmap_size;
1746 dev->inflight_info.fd = vmsg->fds[0] = fd;
1747 vmsg->fd_num = 1;
1748 vmsg->payload.inflight.mmap_offset = 0;
1749
1750 DPRINT("send inflight mmap_size: %"PRId64"\n",
1751 vmsg->payload.inflight.mmap_size);
1752 DPRINT("send inflight mmap offset: %"PRId64"\n",
1753 vmsg->payload.inflight.mmap_offset);
1754
1755 return true;
1756 }
1757
1758 static bool
1759 vu_set_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
1760 {
1761 int fd, i;
1762 uint64_t mmap_size, mmap_offset;
1763 uint16_t num_queues, queue_size;
1764 void *rc;
1765
1766 if (vmsg->fd_num != 1 ||
1767 vmsg->size != sizeof(vmsg->payload.inflight)) {
1768 vu_panic(dev, "Invalid set_inflight_fd message size:%d fds:%d",
1769 vmsg->size, vmsg->fd_num);
1770 return false;
1771 }
1772
1773 fd = vmsg->fds[0];
1774 mmap_size = vmsg->payload.inflight.mmap_size;
1775 mmap_offset = vmsg->payload.inflight.mmap_offset;
1776 num_queues = vmsg->payload.inflight.num_queues;
1777 queue_size = vmsg->payload.inflight.queue_size;
1778
1779 DPRINT("set_inflight_fd mmap_size: %"PRId64"\n", mmap_size);
1780 DPRINT("set_inflight_fd mmap_offset: %"PRId64"\n", mmap_offset);
1781 DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
1782 DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
1783
1784 rc = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
1785 fd, mmap_offset);
1786
1787 if (rc == MAP_FAILED) {
1788 vu_panic(dev, "set_inflight_fd mmap error: %s", strerror(errno));
1789 return false;
1790 }
1791
1792 if (dev->inflight_info.fd) {
1793 close(dev->inflight_info.fd);
1794 }
1795
1796 if (dev->inflight_info.addr) {
1797 munmap(dev->inflight_info.addr, dev->inflight_info.size);
1798 }
1799
1800 dev->inflight_info.fd = fd;
1801 dev->inflight_info.addr = rc;
1802 dev->inflight_info.size = mmap_size;
1803
1804 for (i = 0; i < num_queues; i++) {
1805 dev->vq[i].inflight = (VuVirtqInflight *)rc;
1806 dev->vq[i].inflight->desc_num = queue_size;
1807 rc = (void *)((char *)rc + vu_inflight_queue_size(queue_size));
1808 }
1809
1810 return false;
1811 }
1812
1813 static bool
1814 vu_handle_vring_kick(VuDev *dev, VhostUserMsg *vmsg)
1815 {
1816 unsigned int index = vmsg->payload.state.index;
1817
1818 if (index >= dev->max_queues) {
1819 vu_panic(dev, "Invalid queue index: %u", index);
1820 return false;
1821 }
1822
1823 DPRINT("Got kick message: handler:%p idx:%u\n",
1824 dev->vq[index].handler, index);
1825
1826 if (!dev->vq[index].started) {
1827 dev->vq[index].started = true;
1828
1829 if (dev->iface->queue_set_started) {
1830 dev->iface->queue_set_started(dev, index, true);
1831 }
1832 }
1833
1834 if (dev->vq[index].handler) {
1835 dev->vq[index].handler(dev, index);
1836 }
1837
1838 return false;
1839 }
1840
1841 static bool vu_handle_get_max_memslots(VuDev *dev, VhostUserMsg *vmsg)
1842 {
1843 vmsg_set_reply_u64(vmsg, VHOST_USER_MAX_RAM_SLOTS);
1844
1845 DPRINT("u64: 0x%016"PRIx64"\n", (uint64_t) VHOST_USER_MAX_RAM_SLOTS);
1846
1847 return true;
1848 }
1849
1850 static bool
1851 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
1852 {
1853 int do_reply = 0;
1854
1855 /* Print out generic part of the request. */
1856 DPRINT("================ Vhost user message ================\n");
1857 DPRINT("Request: %s (%d)\n", vu_request_to_string(vmsg->request),
1858 vmsg->request);
1859 DPRINT("Flags: 0x%x\n", vmsg->flags);
1860 DPRINT("Size: %u\n", vmsg->size);
1861
1862 if (vmsg->fd_num) {
1863 int i;
1864 DPRINT("Fds:");
1865 for (i = 0; i < vmsg->fd_num; i++) {
1866 DPRINT(" %d", vmsg->fds[i]);
1867 }
1868 DPRINT("\n");
1869 }
1870
1871 if (dev->iface->process_msg &&
1872 dev->iface->process_msg(dev, vmsg, &do_reply)) {
1873 return do_reply;
1874 }
1875
1876 switch (vmsg->request) {
1877 case VHOST_USER_GET_FEATURES:
1878 return vu_get_features_exec(dev, vmsg);
1879 case VHOST_USER_SET_FEATURES:
1880 return vu_set_features_exec(dev, vmsg);
1881 case VHOST_USER_GET_PROTOCOL_FEATURES:
1882 return vu_get_protocol_features_exec(dev, vmsg);
1883 case VHOST_USER_SET_PROTOCOL_FEATURES:
1884 return vu_set_protocol_features_exec(dev, vmsg);
1885 case VHOST_USER_SET_OWNER:
1886 return vu_set_owner_exec(dev, vmsg);
1887 case VHOST_USER_RESET_OWNER:
1888 return vu_reset_device_exec(dev, vmsg);
1889 case VHOST_USER_SET_MEM_TABLE:
1890 return vu_set_mem_table_exec(dev, vmsg);
1891 case VHOST_USER_SET_LOG_BASE:
1892 return vu_set_log_base_exec(dev, vmsg);
1893 case VHOST_USER_SET_LOG_FD:
1894 return vu_set_log_fd_exec(dev, vmsg);
1895 case VHOST_USER_SET_VRING_NUM:
1896 return vu_set_vring_num_exec(dev, vmsg);
1897 case VHOST_USER_SET_VRING_ADDR:
1898 return vu_set_vring_addr_exec(dev, vmsg);
1899 case VHOST_USER_SET_VRING_BASE:
1900 return vu_set_vring_base_exec(dev, vmsg);
1901 case VHOST_USER_GET_VRING_BASE:
1902 return vu_get_vring_base_exec(dev, vmsg);
1903 case VHOST_USER_SET_VRING_KICK:
1904 return vu_set_vring_kick_exec(dev, vmsg);
1905 case VHOST_USER_SET_VRING_CALL:
1906 return vu_set_vring_call_exec(dev, vmsg);
1907 case VHOST_USER_SET_VRING_ERR:
1908 return vu_set_vring_err_exec(dev, vmsg);
1909 case VHOST_USER_GET_QUEUE_NUM:
1910 return vu_get_queue_num_exec(dev, vmsg);
1911 case VHOST_USER_SET_VRING_ENABLE:
1912 return vu_set_vring_enable_exec(dev, vmsg);
1913 case VHOST_USER_SET_BACKEND_REQ_FD:
1914 return vu_set_slave_req_fd(dev, vmsg);
1915 case VHOST_USER_GET_CONFIG:
1916 return vu_get_config(dev, vmsg);
1917 case VHOST_USER_SET_CONFIG:
1918 return vu_set_config(dev, vmsg);
1919 case VHOST_USER_NONE:
1920 /* if you need processing before exit, override iface->process_msg */
1921 exit(0);
1922 case VHOST_USER_POSTCOPY_ADVISE:
1923 return vu_set_postcopy_advise(dev, vmsg);
1924 case VHOST_USER_POSTCOPY_LISTEN:
1925 return vu_set_postcopy_listen(dev, vmsg);
1926 case VHOST_USER_POSTCOPY_END:
1927 return vu_set_postcopy_end(dev, vmsg);
1928 case VHOST_USER_GET_INFLIGHT_FD:
1929 return vu_get_inflight_fd(dev, vmsg);
1930 case VHOST_USER_SET_INFLIGHT_FD:
1931 return vu_set_inflight_fd(dev, vmsg);
1932 case VHOST_USER_VRING_KICK:
1933 return vu_handle_vring_kick(dev, vmsg);
1934 case VHOST_USER_GET_MAX_MEM_SLOTS:
1935 return vu_handle_get_max_memslots(dev, vmsg);
1936 case VHOST_USER_ADD_MEM_REG:
1937 return vu_add_mem_reg(dev, vmsg);
1938 case VHOST_USER_REM_MEM_REG:
1939 return vu_rem_mem_reg(dev, vmsg);
1940 default:
1941 vmsg_close_fds(vmsg);
1942 vu_panic(dev, "Unhandled request: %d", vmsg->request);
1943 }
1944
1945 return false;
1946 }
1947
1948 bool
1949 vu_dispatch(VuDev *dev)
1950 {
1951 VhostUserMsg vmsg = { 0, };
1952 int reply_requested;
1953 bool need_reply, success = false;
1954
1955 if (!dev->read_msg(dev, dev->sock, &vmsg)) {
1956 goto end;
1957 }
1958
1959 need_reply = vmsg.flags & VHOST_USER_NEED_REPLY_MASK;
1960
1961 reply_requested = vu_process_message(dev, &vmsg);
1962 if (!reply_requested && need_reply) {
1963 vmsg_set_reply_u64(&vmsg, 0);
1964 reply_requested = 1;
1965 }
1966
1967 if (!reply_requested) {
1968 success = true;
1969 goto end;
1970 }
1971
1972 if (!vu_send_reply(dev, dev->sock, &vmsg)) {
1973 goto end;
1974 }
1975
1976 success = true;
1977
1978 end:
1979 free(vmsg.data);
1980 return success;
1981 }
1982
1983 void
1984 vu_deinit(VuDev *dev)
1985 {
1986 unsigned int i;
1987
1988 for (i = 0; i < dev->nregions; i++) {
1989 VuDevRegion *r = &dev->regions[i];
1990 void *m = (void *) (uintptr_t) r->mmap_addr;
1991 if (m != MAP_FAILED) {
1992 munmap(m, r->size + r->mmap_offset);
1993 }
1994 }
1995 dev->nregions = 0;
1996
1997 for (i = 0; i < dev->max_queues; i++) {
1998 VuVirtq *vq = &dev->vq[i];
1999
2000 if (vq->call_fd != -1) {
2001 close(vq->call_fd);
2002 vq->call_fd = -1;
2003 }
2004
2005 if (vq->kick_fd != -1) {
2006 dev->remove_watch(dev, vq->kick_fd);
2007 close(vq->kick_fd);
2008 vq->kick_fd = -1;
2009 }
2010
2011 if (vq->err_fd != -1) {
2012 close(vq->err_fd);
2013 vq->err_fd = -1;
2014 }
2015
2016 if (vq->resubmit_list) {
2017 free(vq->resubmit_list);
2018 vq->resubmit_list = NULL;
2019 }
2020
2021 vq->inflight = NULL;
2022 }
2023
2024 if (dev->inflight_info.addr) {
2025 munmap(dev->inflight_info.addr, dev->inflight_info.size);
2026 dev->inflight_info.addr = NULL;
2027 }
2028
2029 if (dev->inflight_info.fd > 0) {
2030 close(dev->inflight_info.fd);
2031 dev->inflight_info.fd = -1;
2032 }
2033
2034 vu_close_log(dev);
2035 if (dev->slave_fd != -1) {
2036 close(dev->slave_fd);
2037 dev->slave_fd = -1;
2038 }
2039 pthread_mutex_destroy(&dev->slave_mutex);
2040
2041 if (dev->sock != -1) {
2042 close(dev->sock);
2043 }
2044
2045 free(dev->vq);
2046 dev->vq = NULL;
2047 }
2048
2049 bool
2050 vu_init(VuDev *dev,
2051 uint16_t max_queues,
2052 int socket,
2053 vu_panic_cb panic,
2054 vu_read_msg_cb read_msg,
2055 vu_set_watch_cb set_watch,
2056 vu_remove_watch_cb remove_watch,
2057 const VuDevIface *iface)
2058 {
2059 uint16_t i;
2060
2061 assert(max_queues > 0);
2062 assert(socket >= 0);
2063 assert(set_watch);
2064 assert(remove_watch);
2065 assert(iface);
2066 assert(panic);
2067
2068 memset(dev, 0, sizeof(*dev));
2069
2070 dev->sock = socket;
2071 dev->panic = panic;
2072 dev->read_msg = read_msg ? read_msg : vu_message_read_default;
2073 dev->set_watch = set_watch;
2074 dev->remove_watch = remove_watch;
2075 dev->iface = iface;
2076 dev->log_call_fd = -1;
2077 pthread_mutex_init(&dev->slave_mutex, NULL);
2078 dev->slave_fd = -1;
2079 dev->max_queues = max_queues;
2080
2081 dev->vq = malloc(max_queues * sizeof(dev->vq[0]));
2082 if (!dev->vq) {
2083 DPRINT("%s: failed to malloc virtqueues\n", __func__);
2084 return false;
2085 }
2086
2087 for (i = 0; i < max_queues; i++) {
2088 dev->vq[i] = (VuVirtq) {
2089 .call_fd = -1, .kick_fd = -1, .err_fd = -1,
2090 .notification = true,
2091 };
2092 }
2093
2094 return true;
2095 }
2096
2097 VuVirtq *
2098 vu_get_queue(VuDev *dev, int qidx)
2099 {
2100 assert(qidx < dev->max_queues);
2101 return &dev->vq[qidx];
2102 }
2103
2104 bool
2105 vu_queue_enabled(VuDev *dev, VuVirtq *vq)
2106 {
2107 return vq->enable;
2108 }
2109
2110 bool
2111 vu_queue_started(const VuDev *dev, const VuVirtq *vq)
2112 {
2113 return vq->started;
2114 }
2115
2116 static inline uint16_t
2117 vring_avail_flags(VuVirtq *vq)
2118 {
2119 return le16toh(vq->vring.avail->flags);
2120 }
2121
2122 static inline uint16_t
2123 vring_avail_idx(VuVirtq *vq)
2124 {
2125 vq->shadow_avail_idx = le16toh(vq->vring.avail->idx);
2126
2127 return vq->shadow_avail_idx;
2128 }
2129
2130 static inline uint16_t
2131 vring_avail_ring(VuVirtq *vq, int i)
2132 {
2133 return le16toh(vq->vring.avail->ring[i]);
2134 }
2135
2136 static inline uint16_t
2137 vring_get_used_event(VuVirtq *vq)
2138 {
2139 return vring_avail_ring(vq, vq->vring.num);
2140 }
2141
2142 static int
2143 virtqueue_num_heads(VuDev *dev, VuVirtq *vq, unsigned int idx)
2144 {
2145 uint16_t num_heads = vring_avail_idx(vq) - idx;
2146
2147 /* Check it isn't doing very strange things with descriptor numbers. */
2148 if (num_heads > vq->vring.num) {
2149 vu_panic(dev, "Guest moved used index from %u to %u",
2150 idx, vq->shadow_avail_idx);
2151 return -1;
2152 }
2153 if (num_heads) {
2154 /* On success, callers read a descriptor at vq->last_avail_idx.
2155 * Make sure descriptor read does not bypass avail index read. */
2156 smp_rmb();
2157 }
2158
2159 return num_heads;
2160 }
2161
2162 static bool
2163 virtqueue_get_head(VuDev *dev, VuVirtq *vq,
2164 unsigned int idx, unsigned int *head)
2165 {
2166 /* Grab the next descriptor number they're advertising, and increment
2167 * the index we've seen. */
2168 *head = vring_avail_ring(vq, idx % vq->vring.num);
2169
2170 /* If their number is silly, that's a fatal mistake. */
2171 if (*head >= vq->vring.num) {
2172 vu_panic(dev, "Guest says index %u is available", *head);
2173 return false;
2174 }
2175
2176 return true;
2177 }
2178
2179 static int
2180 virtqueue_read_indirect_desc(VuDev *dev, struct vring_desc *desc,
2181 uint64_t addr, size_t len)
2182 {
2183 struct vring_desc *ori_desc;
2184 uint64_t read_len;
2185
2186 if (len > (VIRTQUEUE_MAX_SIZE * sizeof(struct vring_desc))) {
2187 return -1;
2188 }
2189
2190 if (len == 0) {
2191 return -1;
2192 }
2193
2194 while (len) {
2195 read_len = len;
2196 ori_desc = vu_gpa_to_va(dev, &read_len, addr);
2197 if (!ori_desc) {
2198 return -1;
2199 }
2200
2201 memcpy(desc, ori_desc, read_len);
2202 len -= read_len;
2203 addr += read_len;
2204 desc += read_len;
2205 }
2206
2207 return 0;
2208 }
2209
2210 enum {
2211 VIRTQUEUE_READ_DESC_ERROR = -1,
2212 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */
2213 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
2214 };
2215
2216 static int
2217 virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc,
2218 int i, unsigned int max, unsigned int *next)
2219 {
2220 /* If this descriptor says it doesn't chain, we're done. */
2221 if (!(le16toh(desc[i].flags) & VRING_DESC_F_NEXT)) {
2222 return VIRTQUEUE_READ_DESC_DONE;
2223 }
2224
2225 /* Check they're not leading us off end of descriptors. */
2226 *next = le16toh(desc[i].next);
2227 /* Make sure compiler knows to grab that: we don't want it changing! */
2228 smp_wmb();
2229
2230 if (*next >= max) {
2231 vu_panic(dev, "Desc next is %u", *next);
2232 return VIRTQUEUE_READ_DESC_ERROR;
2233 }
2234
2235 return VIRTQUEUE_READ_DESC_MORE;
2236 }
2237
2238 void
2239 vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes,
2240 unsigned int *out_bytes,
2241 unsigned max_in_bytes, unsigned max_out_bytes)
2242 {
2243 unsigned int idx;
2244 unsigned int total_bufs, in_total, out_total;
2245 int rc;
2246
2247 idx = vq->last_avail_idx;
2248
2249 total_bufs = in_total = out_total = 0;
2250 if (unlikely(dev->broken) ||
2251 unlikely(!vq->vring.avail)) {
2252 goto done;
2253 }
2254
2255 while ((rc = virtqueue_num_heads(dev, vq, idx)) > 0) {
2256 unsigned int max, desc_len, num_bufs, indirect = 0;
2257 uint64_t desc_addr, read_len;
2258 struct vring_desc *desc;
2259 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2260 unsigned int i;
2261
2262 max = vq->vring.num;
2263 num_bufs = total_bufs;
2264 if (!virtqueue_get_head(dev, vq, idx++, &i)) {
2265 goto err;
2266 }
2267 desc = vq->vring.desc;
2268
2269 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
2270 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
2271 vu_panic(dev, "Invalid size for indirect buffer table");
2272 goto err;
2273 }
2274
2275 /* If we've got too many, that implies a descriptor loop. */
2276 if (num_bufs >= max) {
2277 vu_panic(dev, "Looped descriptor");
2278 goto err;
2279 }
2280
2281 /* loop over the indirect descriptor table */
2282 indirect = 1;
2283 desc_addr = le64toh(desc[i].addr);
2284 desc_len = le32toh(desc[i].len);
2285 max = desc_len / sizeof(struct vring_desc);
2286 read_len = desc_len;
2287 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2288 if (unlikely(desc && read_len != desc_len)) {
2289 /* Failed to use zero copy */
2290 desc = NULL;
2291 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2292 desc_addr,
2293 desc_len)) {
2294 desc = desc_buf;
2295 }
2296 }
2297 if (!desc) {
2298 vu_panic(dev, "Invalid indirect buffer table");
2299 goto err;
2300 }
2301 num_bufs = i = 0;
2302 }
2303
2304 do {
2305 /* If we've got too many, that implies a descriptor loop. */
2306 if (++num_bufs > max) {
2307 vu_panic(dev, "Looped descriptor");
2308 goto err;
2309 }
2310
2311 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
2312 in_total += le32toh(desc[i].len);
2313 } else {
2314 out_total += le32toh(desc[i].len);
2315 }
2316 if (in_total >= max_in_bytes && out_total >= max_out_bytes) {
2317 goto done;
2318 }
2319 rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
2320 } while (rc == VIRTQUEUE_READ_DESC_MORE);
2321
2322 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
2323 goto err;
2324 }
2325
2326 if (!indirect) {
2327 total_bufs = num_bufs;
2328 } else {
2329 total_bufs++;
2330 }
2331 }
2332 if (rc < 0) {
2333 goto err;
2334 }
2335 done:
2336 if (in_bytes) {
2337 *in_bytes = in_total;
2338 }
2339 if (out_bytes) {
2340 *out_bytes = out_total;
2341 }
2342 return;
2343
2344 err:
2345 in_total = out_total = 0;
2346 goto done;
2347 }
2348
2349 bool
2350 vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes,
2351 unsigned int out_bytes)
2352 {
2353 unsigned int in_total, out_total;
2354
2355 vu_queue_get_avail_bytes(dev, vq, &in_total, &out_total,
2356 in_bytes, out_bytes);
2357
2358 return in_bytes <= in_total && out_bytes <= out_total;
2359 }
2360
2361 /* Fetch avail_idx from VQ memory only when we really need to know if
2362 * guest has added some buffers. */
2363 bool
2364 vu_queue_empty(VuDev *dev, VuVirtq *vq)
2365 {
2366 if (unlikely(dev->broken) ||
2367 unlikely(!vq->vring.avail)) {
2368 return true;
2369 }
2370
2371 if (vq->shadow_avail_idx != vq->last_avail_idx) {
2372 return false;
2373 }
2374
2375 return vring_avail_idx(vq) == vq->last_avail_idx;
2376 }
2377
2378 static bool
2379 vring_notify(VuDev *dev, VuVirtq *vq)
2380 {
2381 uint16_t old, new;
2382 bool v;
2383
2384 /* We need to expose used array entries before checking used event. */
2385 smp_mb();
2386
2387 /* Always notify when queue is empty (when feature acknowledge) */
2388 if (vu_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
2389 !vq->inuse && vu_queue_empty(dev, vq)) {
2390 return true;
2391 }
2392
2393 if (!vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2394 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
2395 }
2396
2397 v = vq->signalled_used_valid;
2398 vq->signalled_used_valid = true;
2399 old = vq->signalled_used;
2400 new = vq->signalled_used = vq->used_idx;
2401 return !v || vring_need_event(vring_get_used_event(vq), new, old);
2402 }
2403
2404 static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
2405 {
2406 if (unlikely(dev->broken) ||
2407 unlikely(!vq->vring.avail)) {
2408 return;
2409 }
2410
2411 if (!vring_notify(dev, vq)) {
2412 DPRINT("skipped notify...\n");
2413 return;
2414 }
2415
2416 if (vq->call_fd < 0 &&
2417 vu_has_protocol_feature(dev,
2418 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
2419 vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ)) {
2420 VhostUserMsg vmsg = {
2421 .request = VHOST_USER_BACKEND_VRING_CALL,
2422 .flags = VHOST_USER_VERSION,
2423 .size = sizeof(vmsg.payload.state),
2424 .payload.state = {
2425 .index = vq - dev->vq,
2426 },
2427 };
2428 bool ack = sync &&
2429 vu_has_protocol_feature(dev,
2430 VHOST_USER_PROTOCOL_F_REPLY_ACK);
2431
2432 if (ack) {
2433 vmsg.flags |= VHOST_USER_NEED_REPLY_MASK;
2434 }
2435
2436 vu_message_write(dev, dev->slave_fd, &vmsg);
2437 if (ack) {
2438 vu_message_read_default(dev, dev->slave_fd, &vmsg);
2439 }
2440 return;
2441 }
2442
2443 if (eventfd_write(vq->call_fd, 1) < 0) {
2444 vu_panic(dev, "Error writing eventfd: %s", strerror(errno));
2445 }
2446 }
2447
2448 void vu_queue_notify(VuDev *dev, VuVirtq *vq)
2449 {
2450 _vu_queue_notify(dev, vq, false);
2451 }
2452
2453 void vu_queue_notify_sync(VuDev *dev, VuVirtq *vq)
2454 {
2455 _vu_queue_notify(dev, vq, true);
2456 }
2457
2458 static inline void
2459 vring_used_flags_set_bit(VuVirtq *vq, int mask)
2460 {
2461 uint16_t *flags;
2462
2463 flags = (uint16_t *)((char*)vq->vring.used +
2464 offsetof(struct vring_used, flags));
2465 *flags = htole16(le16toh(*flags) | mask);
2466 }
2467
2468 static inline void
2469 vring_used_flags_unset_bit(VuVirtq *vq, int mask)
2470 {
2471 uint16_t *flags;
2472
2473 flags = (uint16_t *)((char*)vq->vring.used +
2474 offsetof(struct vring_used, flags));
2475 *flags = htole16(le16toh(*flags) & ~mask);
2476 }
2477
2478 static inline void
2479 vring_set_avail_event(VuVirtq *vq, uint16_t val)
2480 {
2481 uint16_t val_le = htole16(val);
2482
2483 if (!vq->notification) {
2484 return;
2485 }
2486
2487 memcpy(&vq->vring.used->ring[vq->vring.num], &val_le, sizeof(uint16_t));
2488 }
2489
2490 void
2491 vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int enable)
2492 {
2493 vq->notification = enable;
2494 if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2495 vring_set_avail_event(vq, vring_avail_idx(vq));
2496 } else if (enable) {
2497 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
2498 } else {
2499 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY);
2500 }
2501 if (enable) {
2502 /* Expose avail event/used flags before caller checks the avail idx. */
2503 smp_mb();
2504 }
2505 }
2506
2507 static bool
2508 virtqueue_map_desc(VuDev *dev,
2509 unsigned int *p_num_sg, struct iovec *iov,
2510 unsigned int max_num_sg, bool is_write,
2511 uint64_t pa, size_t sz)
2512 {
2513 unsigned num_sg = *p_num_sg;
2514
2515 assert(num_sg <= max_num_sg);
2516
2517 if (!sz) {
2518 vu_panic(dev, "virtio: zero sized buffers are not allowed");
2519 return false;
2520 }
2521
2522 while (sz) {
2523 uint64_t len = sz;
2524
2525 if (num_sg == max_num_sg) {
2526 vu_panic(dev, "virtio: too many descriptors in indirect table");
2527 return false;
2528 }
2529
2530 iov[num_sg].iov_base = vu_gpa_to_va(dev, &len, pa);
2531 if (iov[num_sg].iov_base == NULL) {
2532 vu_panic(dev, "virtio: invalid address for buffers");
2533 return false;
2534 }
2535 iov[num_sg].iov_len = len;
2536 num_sg++;
2537 sz -= len;
2538 pa += len;
2539 }
2540
2541 *p_num_sg = num_sg;
2542 return true;
2543 }
2544
2545 static void *
2546 virtqueue_alloc_element(size_t sz,
2547 unsigned out_num, unsigned in_num)
2548 {
2549 VuVirtqElement *elem;
2550 size_t in_sg_ofs = ALIGN_UP(sz, __alignof__(elem->in_sg[0]));
2551 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]);
2552 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]);
2553
2554 assert(sz >= sizeof(VuVirtqElement));
2555 elem = malloc(out_sg_end);
2556 if (!elem) {
2557 DPRINT("%s: failed to malloc virtqueue element\n", __func__);
2558 return NULL;
2559 }
2560 elem->out_num = out_num;
2561 elem->in_num = in_num;
2562 elem->in_sg = (void *)elem + in_sg_ofs;
2563 elem->out_sg = (void *)elem + out_sg_ofs;
2564 return elem;
2565 }
2566
2567 static void *
2568 vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz)
2569 {
2570 struct vring_desc *desc = vq->vring.desc;
2571 uint64_t desc_addr, read_len;
2572 unsigned int desc_len;
2573 unsigned int max = vq->vring.num;
2574 unsigned int i = idx;
2575 VuVirtqElement *elem;
2576 unsigned int out_num = 0, in_num = 0;
2577 struct iovec iov[VIRTQUEUE_MAX_SIZE];
2578 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2579 int rc;
2580
2581 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
2582 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
2583 vu_panic(dev, "Invalid size for indirect buffer table");
2584 return NULL;
2585 }
2586
2587 /* loop over the indirect descriptor table */
2588 desc_addr = le64toh(desc[i].addr);
2589 desc_len = le32toh(desc[i].len);
2590 max = desc_len / sizeof(struct vring_desc);
2591 read_len = desc_len;
2592 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2593 if (unlikely(desc && read_len != desc_len)) {
2594 /* Failed to use zero copy */
2595 desc = NULL;
2596 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2597 desc_addr,
2598 desc_len)) {
2599 desc = desc_buf;
2600 }
2601 }
2602 if (!desc) {
2603 vu_panic(dev, "Invalid indirect buffer table");
2604 return NULL;
2605 }
2606 i = 0;
2607 }
2608
2609 /* Collect all the descriptors */
2610 do {
2611 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
2612 if (!virtqueue_map_desc(dev, &in_num, iov + out_num,
2613 VIRTQUEUE_MAX_SIZE - out_num, true,
2614 le64toh(desc[i].addr),
2615 le32toh(desc[i].len))) {
2616 return NULL;
2617 }
2618 } else {
2619 if (in_num) {
2620 vu_panic(dev, "Incorrect order for descriptors");
2621 return NULL;
2622 }
2623 if (!virtqueue_map_desc(dev, &out_num, iov,
2624 VIRTQUEUE_MAX_SIZE, false,
2625 le64toh(desc[i].addr),
2626 le32toh(desc[i].len))) {
2627 return NULL;
2628 }
2629 }
2630
2631 /* If we've got too many, that implies a descriptor loop. */
2632 if ((in_num + out_num) > max) {
2633 vu_panic(dev, "Looped descriptor");
2634 return NULL;
2635 }
2636 rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
2637 } while (rc == VIRTQUEUE_READ_DESC_MORE);
2638
2639 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
2640 vu_panic(dev, "read descriptor error");
2641 return NULL;
2642 }
2643
2644 /* Now copy what we have collected and mapped */
2645 elem = virtqueue_alloc_element(sz, out_num, in_num);
2646 if (!elem) {
2647 return NULL;
2648 }
2649 elem->index = idx;
2650 for (i = 0; i < out_num; i++) {
2651 elem->out_sg[i] = iov[i];
2652 }
2653 for (i = 0; i < in_num; i++) {
2654 elem->in_sg[i] = iov[out_num + i];
2655 }
2656
2657 return elem;
2658 }
2659
2660 static int
2661 vu_queue_inflight_get(VuDev *dev, VuVirtq *vq, int desc_idx)
2662 {
2663 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2664 return 0;
2665 }
2666
2667 if (unlikely(!vq->inflight)) {
2668 return -1;
2669 }
2670
2671 vq->inflight->desc[desc_idx].counter = vq->counter++;
2672 vq->inflight->desc[desc_idx].inflight = 1;
2673
2674 return 0;
2675 }
2676
2677 static int
2678 vu_queue_inflight_pre_put(VuDev *dev, VuVirtq *vq, int desc_idx)
2679 {
2680 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2681 return 0;
2682 }
2683
2684 if (unlikely(!vq->inflight)) {
2685 return -1;
2686 }
2687
2688 vq->inflight->last_batch_head = desc_idx;
2689
2690 return 0;
2691 }
2692
2693 static int
2694 vu_queue_inflight_post_put(VuDev *dev, VuVirtq *vq, int desc_idx)
2695 {
2696 if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
2697 return 0;
2698 }
2699
2700 if (unlikely(!vq->inflight)) {
2701 return -1;
2702 }
2703
2704 barrier();
2705
2706 vq->inflight->desc[desc_idx].inflight = 0;
2707
2708 barrier();
2709
2710 vq->inflight->used_idx = vq->used_idx;
2711
2712 return 0;
2713 }
2714
2715 void *
2716 vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
2717 {
2718 int i;
2719 unsigned int head;
2720 VuVirtqElement *elem;
2721
2722 if (unlikely(dev->broken) ||
2723 unlikely(!vq->vring.avail)) {
2724 return NULL;
2725 }
2726
2727 if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
2728 i = (--vq->resubmit_num);
2729 elem = vu_queue_map_desc(dev, vq, vq->resubmit_list[i].index, sz);
2730
2731 if (!vq->resubmit_num) {
2732 free(vq->resubmit_list);
2733 vq->resubmit_list = NULL;
2734 }
2735
2736 return elem;
2737 }
2738
2739 if (vu_queue_empty(dev, vq)) {
2740 return NULL;
2741 }
2742 /*
2743 * Needed after virtio_queue_empty(), see comment in
2744 * virtqueue_num_heads().
2745 */
2746 smp_rmb();
2747
2748 if (vq->inuse >= vq->vring.num) {
2749 vu_panic(dev, "Virtqueue size exceeded");
2750 return NULL;
2751 }
2752
2753 if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
2754 return NULL;
2755 }
2756
2757 if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
2758 vring_set_avail_event(vq, vq->last_avail_idx);
2759 }
2760
2761 elem = vu_queue_map_desc(dev, vq, head, sz);
2762
2763 if (!elem) {
2764 return NULL;
2765 }
2766
2767 vq->inuse++;
2768
2769 vu_queue_inflight_get(dev, vq, head);
2770
2771 return elem;
2772 }
2773
2774 static void
2775 vu_queue_detach_element(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
2776 size_t len)
2777 {
2778 vq->inuse--;
2779 /* unmap, when DMA support is added */
2780 }
2781
2782 void
2783 vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
2784 size_t len)
2785 {
2786 vq->last_avail_idx--;
2787 vu_queue_detach_element(dev, vq, elem, len);
2788 }
2789
2790 bool
2791 vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num)
2792 {
2793 if (num > vq->inuse) {
2794 return false;
2795 }
2796 vq->last_avail_idx -= num;
2797 vq->inuse -= num;
2798 return true;
2799 }
2800
2801 static inline
2802 void vring_used_write(VuDev *dev, VuVirtq *vq,
2803 struct vring_used_elem *uelem, int i)
2804 {
2805 struct vring_used *used = vq->vring.used;
2806
2807 used->ring[i] = *uelem;
2808 vu_log_write(dev, vq->vring.log_guest_addr +
2809 offsetof(struct vring_used, ring[i]),
2810 sizeof(used->ring[i]));
2811 }
2812
2813
2814 static void
2815 vu_log_queue_fill(VuDev *dev, VuVirtq *vq,
2816 const VuVirtqElement *elem,
2817 unsigned int len)
2818 {
2819 struct vring_desc *desc = vq->vring.desc;
2820 unsigned int i, max, min, desc_len;
2821 uint64_t desc_addr, read_len;
2822 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
2823 unsigned num_bufs = 0;
2824
2825 max = vq->vring.num;
2826 i = elem->index;
2827
2828 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
2829 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
2830 vu_panic(dev, "Invalid size for indirect buffer table");
2831 return;
2832 }
2833
2834 /* loop over the indirect descriptor table */
2835 desc_addr = le64toh(desc[i].addr);
2836 desc_len = le32toh(desc[i].len);
2837 max = desc_len / sizeof(struct vring_desc);
2838 read_len = desc_len;
2839 desc = vu_gpa_to_va(dev, &read_len, desc_addr);
2840 if (unlikely(desc && read_len != desc_len)) {
2841 /* Failed to use zero copy */
2842 desc = NULL;
2843 if (!virtqueue_read_indirect_desc(dev, desc_buf,
2844 desc_addr,
2845 desc_len)) {
2846 desc = desc_buf;
2847 }
2848 }
2849 if (!desc) {
2850 vu_panic(dev, "Invalid indirect buffer table");
2851 return;
2852 }
2853 i = 0;
2854 }
2855
2856 do {
2857 if (++num_bufs > max) {
2858 vu_panic(dev, "Looped descriptor");
2859 return;
2860 }
2861
2862 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
2863 min = MIN(le32toh(desc[i].len), len);
2864 vu_log_write(dev, le64toh(desc[i].addr), min);
2865 len -= min;
2866 }
2867
2868 } while (len > 0 &&
2869 (virtqueue_read_next_desc(dev, desc, i, max, &i)
2870 == VIRTQUEUE_READ_DESC_MORE));
2871 }
2872
2873 void
2874 vu_queue_fill(VuDev *dev, VuVirtq *vq,
2875 const VuVirtqElement *elem,
2876 unsigned int len, unsigned int idx)
2877 {
2878 struct vring_used_elem uelem;
2879
2880 if (unlikely(dev->broken) ||
2881 unlikely(!vq->vring.avail)) {
2882 return;
2883 }
2884
2885 vu_log_queue_fill(dev, vq, elem, len);
2886
2887 idx = (idx + vq->used_idx) % vq->vring.num;
2888
2889 uelem.id = htole32(elem->index);
2890 uelem.len = htole32(len);
2891 vring_used_write(dev, vq, &uelem, idx);
2892 }
2893
2894 static inline
2895 void vring_used_idx_set(VuDev *dev, VuVirtq *vq, uint16_t val)
2896 {
2897 vq->vring.used->idx = htole16(val);
2898 vu_log_write(dev,
2899 vq->vring.log_guest_addr + offsetof(struct vring_used, idx),
2900 sizeof(vq->vring.used->idx));
2901
2902 vq->used_idx = val;
2903 }
2904
2905 void
2906 vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int count)
2907 {
2908 uint16_t old, new;
2909
2910 if (unlikely(dev->broken) ||
2911 unlikely(!vq->vring.avail)) {
2912 return;
2913 }
2914
2915 /* Make sure buffer is written before we update index. */
2916 smp_wmb();
2917
2918 old = vq->used_idx;
2919 new = old + count;
2920 vring_used_idx_set(dev, vq, new);
2921 vq->inuse -= count;
2922 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) {
2923 vq->signalled_used_valid = false;
2924 }
2925 }
2926
2927 void
2928 vu_queue_push(VuDev *dev, VuVirtq *vq,
2929 const VuVirtqElement *elem, unsigned int len)
2930 {
2931 vu_queue_fill(dev, vq, elem, len, 0);
2932 vu_queue_inflight_pre_put(dev, vq, elem->index);
2933 vu_queue_flush(dev, vq, 1);
2934 vu_queue_inflight_post_put(dev, vq, elem->index);
2935 }
armbru's QEMU hackery