xref: /openbmc/qemu/hw/virtio/vhost-user.c (revision 4b773fc2)
1 /*
2  * vhost-user
3  *
4  * Copyright (c) 2013 Virtual Open Systems Sarl.
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  *
9  */
10 
11 #include "qemu/osdep.h"
12 #include "qapi/error.h"
13 #include "hw/virtio/vhost.h"
14 #include "hw/virtio/vhost-user.h"
15 #include "hw/virtio/vhost-backend.h"
16 #include "hw/virtio/virtio.h"
17 #include "hw/virtio/virtio-net.h"
18 #include "chardev/char-fe.h"
19 #include "sysemu/kvm.h"
20 #include "qemu/error-report.h"
21 #include "qemu/main-loop.h"
22 #include "qemu/sockets.h"
23 #include "sysemu/cryptodev.h"
24 #include "migration/migration.h"
25 #include "migration/postcopy-ram.h"
26 #include "trace.h"
27 
28 #include <sys/ioctl.h>
29 #include <sys/socket.h>
30 #include <sys/un.h>
31 
32 #include "standard-headers/linux/vhost_types.h"
33 
34 #ifdef CONFIG_LINUX
35 #include <linux/userfaultfd.h>
36 #endif
37 
38 #define VHOST_MEMORY_MAX_NREGIONS    8
39 #define VHOST_USER_F_PROTOCOL_FEATURES 30
40 #define VHOST_USER_SLAVE_MAX_FDS     8
41 
42 /*
43  * Maximum size of virtio device config space
44  */
45 #define VHOST_USER_MAX_CONFIG_SIZE 256
46 
47 enum VhostUserProtocolFeature {
48     VHOST_USER_PROTOCOL_F_MQ = 0,
49     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
50     VHOST_USER_PROTOCOL_F_RARP = 2,
51     VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
52     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
53     VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
54     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
55     VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
56     VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
57     VHOST_USER_PROTOCOL_F_CONFIG = 9,
58     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
59     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
60     VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12,
61     VHOST_USER_PROTOCOL_F_RESET_DEVICE = 13,
62     VHOST_USER_PROTOCOL_F_MAX
63 };
64 
65 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
66 
67 typedef enum VhostUserRequest {
68     VHOST_USER_NONE = 0,
69     VHOST_USER_GET_FEATURES = 1,
70     VHOST_USER_SET_FEATURES = 2,
71     VHOST_USER_SET_OWNER = 3,
72     VHOST_USER_RESET_OWNER = 4,
73     VHOST_USER_SET_MEM_TABLE = 5,
74     VHOST_USER_SET_LOG_BASE = 6,
75     VHOST_USER_SET_LOG_FD = 7,
76     VHOST_USER_SET_VRING_NUM = 8,
77     VHOST_USER_SET_VRING_ADDR = 9,
78     VHOST_USER_SET_VRING_BASE = 10,
79     VHOST_USER_GET_VRING_BASE = 11,
80     VHOST_USER_SET_VRING_KICK = 12,
81     VHOST_USER_SET_VRING_CALL = 13,
82     VHOST_USER_SET_VRING_ERR = 14,
83     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
84     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
85     VHOST_USER_GET_QUEUE_NUM = 17,
86     VHOST_USER_SET_VRING_ENABLE = 18,
87     VHOST_USER_SEND_RARP = 19,
88     VHOST_USER_NET_SET_MTU = 20,
89     VHOST_USER_SET_SLAVE_REQ_FD = 21,
90     VHOST_USER_IOTLB_MSG = 22,
91     VHOST_USER_SET_VRING_ENDIAN = 23,
92     VHOST_USER_GET_CONFIG = 24,
93     VHOST_USER_SET_CONFIG = 25,
94     VHOST_USER_CREATE_CRYPTO_SESSION = 26,
95     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
96     VHOST_USER_POSTCOPY_ADVISE  = 28,
97     VHOST_USER_POSTCOPY_LISTEN  = 29,
98     VHOST_USER_POSTCOPY_END     = 30,
99     VHOST_USER_GET_INFLIGHT_FD = 31,
100     VHOST_USER_SET_INFLIGHT_FD = 32,
101     VHOST_USER_GPU_SET_SOCKET = 33,
102     VHOST_USER_RESET_DEVICE = 34,
103     VHOST_USER_MAX
104 } VhostUserRequest;
105 
106 typedef enum VhostUserSlaveRequest {
107     VHOST_USER_SLAVE_NONE = 0,
108     VHOST_USER_SLAVE_IOTLB_MSG = 1,
109     VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
110     VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
111     VHOST_USER_SLAVE_MAX
112 }  VhostUserSlaveRequest;
113 
114 typedef struct VhostUserMemoryRegion {
115     uint64_t guest_phys_addr;
116     uint64_t memory_size;
117     uint64_t userspace_addr;
118     uint64_t mmap_offset;
119 } VhostUserMemoryRegion;
120 
121 typedef struct VhostUserMemory {
122     uint32_t nregions;
123     uint32_t padding;
124     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
125 } VhostUserMemory;
126 
127 typedef struct VhostUserLog {
128     uint64_t mmap_size;
129     uint64_t mmap_offset;
130 } VhostUserLog;
131 
132 typedef struct VhostUserConfig {
133     uint32_t offset;
134     uint32_t size;
135     uint32_t flags;
136     uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
137 } VhostUserConfig;
138 
139 #define VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN    512
140 #define VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN  64
141 
142 typedef struct VhostUserCryptoSession {
143     /* session id for success, -1 on errors */
144     int64_t session_id;
145     CryptoDevBackendSymSessionInfo session_setup_data;
146     uint8_t key[VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN];
147     uint8_t auth_key[VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN];
148 } VhostUserCryptoSession;
149 
150 static VhostUserConfig c __attribute__ ((unused));
151 #define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
152                                    + sizeof(c.size) \
153                                    + sizeof(c.flags))
154 
155 typedef struct VhostUserVringArea {
156     uint64_t u64;
157     uint64_t size;
158     uint64_t offset;
159 } VhostUserVringArea;
160 
161 typedef struct VhostUserInflight {
162     uint64_t mmap_size;
163     uint64_t mmap_offset;
164     uint16_t num_queues;
165     uint16_t queue_size;
166 } VhostUserInflight;
167 
168 typedef struct {
169     VhostUserRequest request;
170 
171 #define VHOST_USER_VERSION_MASK     (0x3)
172 #define VHOST_USER_REPLY_MASK       (0x1<<2)
173 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
174     uint32_t flags;
175     uint32_t size; /* the following payload size */
176 } QEMU_PACKED VhostUserHeader;
177 
178 typedef union {
179 #define VHOST_USER_VRING_IDX_MASK   (0xff)
180 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
181         uint64_t u64;
182         struct vhost_vring_state state;
183         struct vhost_vring_addr addr;
184         VhostUserMemory memory;
185         VhostUserLog log;
186         struct vhost_iotlb_msg iotlb;
187         VhostUserConfig config;
188         VhostUserCryptoSession session;
189         VhostUserVringArea area;
190         VhostUserInflight inflight;
191 } VhostUserPayload;
192 
193 typedef struct VhostUserMsg {
194     VhostUserHeader hdr;
195     VhostUserPayload payload;
196 } QEMU_PACKED VhostUserMsg;
197 
198 static VhostUserMsg m __attribute__ ((unused));
199 #define VHOST_USER_HDR_SIZE (sizeof(VhostUserHeader))
200 
201 #define VHOST_USER_PAYLOAD_SIZE (sizeof(VhostUserPayload))
202 
203 /* The version of the protocol we support */
204 #define VHOST_USER_VERSION    (0x1)
205 
206 struct vhost_user {
207     struct vhost_dev *dev;
208     /* Shared between vhost devs of the same virtio device */
209     VhostUserState *user;
210     int slave_fd;
211     NotifierWithReturn postcopy_notifier;
212     struct PostCopyFD  postcopy_fd;
213     uint64_t           postcopy_client_bases[VHOST_MEMORY_MAX_NREGIONS];
214     /* Length of the region_rb and region_rb_offset arrays */
215     size_t             region_rb_len;
216     /* RAMBlock associated with a given region */
217     RAMBlock         **region_rb;
218     /* The offset from the start of the RAMBlock to the start of the
219      * vhost region.
220      */
221     ram_addr_t        *region_rb_offset;
222 
223     /* True once we've entered postcopy_listen */
224     bool               postcopy_listen;
225 };
226 
227 static bool ioeventfd_enabled(void)
228 {
229     return !kvm_enabled() || kvm_eventfds_enabled();
230 }
231 
232 static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
233 {
234     struct vhost_user *u = dev->opaque;
235     CharBackend *chr = u->user->chr;
236     uint8_t *p = (uint8_t *) msg;
237     int r, size = VHOST_USER_HDR_SIZE;
238 
239     r = qemu_chr_fe_read_all(chr, p, size);
240     if (r != size) {
241         error_report("Failed to read msg header. Read %d instead of %d."
242                      " Original request %d.", r, size, msg->hdr.request);
243         return -1;
244     }
245 
246     /* validate received flags */
247     if (msg->hdr.flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
248         error_report("Failed to read msg header."
249                 " Flags 0x%x instead of 0x%x.", msg->hdr.flags,
250                 VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
251         return -1;
252     }
253 
254     return 0;
255 }
256 
257 static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
258 {
259     struct vhost_user *u = dev->opaque;
260     CharBackend *chr = u->user->chr;
261     uint8_t *p = (uint8_t *) msg;
262     int r, size;
263 
264     if (vhost_user_read_header(dev, msg) < 0) {
265         return -1;
266     }
267 
268     /* validate message size is sane */
269     if (msg->hdr.size > VHOST_USER_PAYLOAD_SIZE) {
270         error_report("Failed to read msg header."
271                 " Size %d exceeds the maximum %zu.", msg->hdr.size,
272                 VHOST_USER_PAYLOAD_SIZE);
273         return -1;
274     }
275 
276     if (msg->hdr.size) {
277         p += VHOST_USER_HDR_SIZE;
278         size = msg->hdr.size;
279         r = qemu_chr_fe_read_all(chr, p, size);
280         if (r != size) {
281             error_report("Failed to read msg payload."
282                          " Read %d instead of %d.", r, msg->hdr.size);
283             return -1;
284         }
285     }
286 
287     return 0;
288 }
289 
290 static int process_message_reply(struct vhost_dev *dev,
291                                  const VhostUserMsg *msg)
292 {
293     VhostUserMsg msg_reply;
294 
295     if ((msg->hdr.flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
296         return 0;
297     }
298 
299     if (vhost_user_read(dev, &msg_reply) < 0) {
300         return -1;
301     }
302 
303     if (msg_reply.hdr.request != msg->hdr.request) {
304         error_report("Received unexpected msg type."
305                      "Expected %d received %d",
306                      msg->hdr.request, msg_reply.hdr.request);
307         return -1;
308     }
309 
310     return msg_reply.payload.u64 ? -1 : 0;
311 }
312 
313 static bool vhost_user_one_time_request(VhostUserRequest request)
314 {
315     switch (request) {
316     case VHOST_USER_SET_OWNER:
317     case VHOST_USER_RESET_OWNER:
318     case VHOST_USER_SET_MEM_TABLE:
319     case VHOST_USER_GET_QUEUE_NUM:
320     case VHOST_USER_NET_SET_MTU:
321         return true;
322     default:
323         return false;
324     }
325 }
326 
327 /* most non-init callers ignore the error */
328 static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
329                             int *fds, int fd_num)
330 {
331     struct vhost_user *u = dev->opaque;
332     CharBackend *chr = u->user->chr;
333     int ret, size = VHOST_USER_HDR_SIZE + msg->hdr.size;
334 
335     /*
336      * For non-vring specific requests, like VHOST_USER_SET_MEM_TABLE,
337      * we just need send it once in the first time. For later such
338      * request, we just ignore it.
339      */
340     if (vhost_user_one_time_request(msg->hdr.request) && dev->vq_index != 0) {
341         msg->hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
342         return 0;
343     }
344 
345     if (qemu_chr_fe_set_msgfds(chr, fds, fd_num) < 0) {
346         error_report("Failed to set msg fds.");
347         return -1;
348     }
349 
350     ret = qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size);
351     if (ret != size) {
352         error_report("Failed to write msg."
353                      " Wrote %d instead of %d.", ret, size);
354         return -1;
355     }
356 
357     return 0;
358 }
359 
360 int vhost_user_gpu_set_socket(struct vhost_dev *dev, int fd)
361 {
362     VhostUserMsg msg = {
363         .hdr.request = VHOST_USER_GPU_SET_SOCKET,
364         .hdr.flags = VHOST_USER_VERSION,
365     };
366 
367     return vhost_user_write(dev, &msg, &fd, 1);
368 }
369 
370 static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
371                                    struct vhost_log *log)
372 {
373     int fds[VHOST_MEMORY_MAX_NREGIONS];
374     size_t fd_num = 0;
375     bool shmfd = virtio_has_feature(dev->protocol_features,
376                                     VHOST_USER_PROTOCOL_F_LOG_SHMFD);
377     VhostUserMsg msg = {
378         .hdr.request = VHOST_USER_SET_LOG_BASE,
379         .hdr.flags = VHOST_USER_VERSION,
380         .payload.log.mmap_size = log->size * sizeof(*(log->log)),
381         .payload.log.mmap_offset = 0,
382         .hdr.size = sizeof(msg.payload.log),
383     };
384 
385     if (shmfd && log->fd != -1) {
386         fds[fd_num++] = log->fd;
387     }
388 
389     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
390         return -1;
391     }
392 
393     if (shmfd) {
394         msg.hdr.size = 0;
395         if (vhost_user_read(dev, &msg) < 0) {
396             return -1;
397         }
398 
399         if (msg.hdr.request != VHOST_USER_SET_LOG_BASE) {
400             error_report("Received unexpected msg type. "
401                          "Expected %d received %d",
402                          VHOST_USER_SET_LOG_BASE, msg.hdr.request);
403             return -1;
404         }
405     }
406 
407     return 0;
408 }
409 
410 static int vhost_user_fill_set_mem_table_msg(struct vhost_user *u,
411                                              struct vhost_dev *dev,
412                                              VhostUserMsg *msg,
413                                              int *fds, size_t *fd_num,
414                                              bool track_ramblocks)
415 {
416     int i, fd;
417     ram_addr_t offset;
418     MemoryRegion *mr;
419     struct vhost_memory_region *reg;
420 
421     msg->hdr.request = VHOST_USER_SET_MEM_TABLE;
422 
423     for (i = 0; i < dev->mem->nregions; ++i) {
424         reg = dev->mem->regions + i;
425 
426         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
427         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
428                                      &offset);
429         fd = memory_region_get_fd(mr);
430         if (fd > 0) {
431             if (track_ramblocks) {
432                 assert(*fd_num < VHOST_MEMORY_MAX_NREGIONS);
433                 trace_vhost_user_set_mem_table_withfd(*fd_num, mr->name,
434                                                       reg->memory_size,
435                                                       reg->guest_phys_addr,
436                                                       reg->userspace_addr,
437                                                       offset);
438                 u->region_rb_offset[i] = offset;
439                 u->region_rb[i] = mr->ram_block;
440             } else if (*fd_num == VHOST_MEMORY_MAX_NREGIONS) {
441                 error_report("Failed preparing vhost-user memory table msg");
442                 return -1;
443             }
444             msg->payload.memory.regions[*fd_num].userspace_addr =
445                 reg->userspace_addr;
446             msg->payload.memory.regions[*fd_num].memory_size =
447                 reg->memory_size;
448             msg->payload.memory.regions[*fd_num].guest_phys_addr =
449                 reg->guest_phys_addr;
450             msg->payload.memory.regions[*fd_num].mmap_offset = offset;
451             fds[(*fd_num)++] = fd;
452         } else if (track_ramblocks) {
453             u->region_rb_offset[i] = 0;
454             u->region_rb[i] = NULL;
455         }
456     }
457 
458     msg->payload.memory.nregions = *fd_num;
459 
460     if (!*fd_num) {
461         error_report("Failed initializing vhost-user memory map, "
462                      "consider using -object memory-backend-file share=on");
463         return -1;
464     }
465 
466     msg->hdr.size = sizeof(msg->payload.memory.nregions);
467     msg->hdr.size += sizeof(msg->payload.memory.padding);
468     msg->hdr.size += *fd_num * sizeof(VhostUserMemoryRegion);
469 
470     return 1;
471 }
472 
473 static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
474                                              struct vhost_memory *mem)
475 {
476     struct vhost_user *u = dev->opaque;
477     int fds[VHOST_MEMORY_MAX_NREGIONS];
478     size_t fd_num = 0;
479     VhostUserMsg msg_reply;
480     int region_i, msg_i;
481 
482     VhostUserMsg msg = {
483         .hdr.flags = VHOST_USER_VERSION,
484     };
485 
486     if (u->region_rb_len < dev->mem->nregions) {
487         u->region_rb = g_renew(RAMBlock*, u->region_rb, dev->mem->nregions);
488         u->region_rb_offset = g_renew(ram_addr_t, u->region_rb_offset,
489                                       dev->mem->nregions);
490         memset(&(u->region_rb[u->region_rb_len]), '\0',
491                sizeof(RAMBlock *) * (dev->mem->nregions - u->region_rb_len));
492         memset(&(u->region_rb_offset[u->region_rb_len]), '\0',
493                sizeof(ram_addr_t) * (dev->mem->nregions - u->region_rb_len));
494         u->region_rb_len = dev->mem->nregions;
495     }
496 
497     if (vhost_user_fill_set_mem_table_msg(u, dev, &msg, fds, &fd_num,
498                                           true) < 0) {
499         return -1;
500     }
501 
502     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
503         return -1;
504     }
505 
506     if (vhost_user_read(dev, &msg_reply) < 0) {
507         return -1;
508     }
509 
510     if (msg_reply.hdr.request != VHOST_USER_SET_MEM_TABLE) {
511         error_report("%s: Received unexpected msg type."
512                      "Expected %d received %d", __func__,
513                      VHOST_USER_SET_MEM_TABLE, msg_reply.hdr.request);
514         return -1;
515     }
516     /* We're using the same structure, just reusing one of the
517      * fields, so it should be the same size.
518      */
519     if (msg_reply.hdr.size != msg.hdr.size) {
520         error_report("%s: Unexpected size for postcopy reply "
521                      "%d vs %d", __func__, msg_reply.hdr.size, msg.hdr.size);
522         return -1;
523     }
524 
525     memset(u->postcopy_client_bases, 0,
526            sizeof(uint64_t) * VHOST_MEMORY_MAX_NREGIONS);
527 
528     /* They're in the same order as the regions that were sent
529      * but some of the regions were skipped (above) if they
530      * didn't have fd's
531     */
532     for (msg_i = 0, region_i = 0;
533          region_i < dev->mem->nregions;
534         region_i++) {
535         if (msg_i < fd_num &&
536             msg_reply.payload.memory.regions[msg_i].guest_phys_addr ==
537             dev->mem->regions[region_i].guest_phys_addr) {
538             u->postcopy_client_bases[region_i] =
539                 msg_reply.payload.memory.regions[msg_i].userspace_addr;
540             trace_vhost_user_set_mem_table_postcopy(
541                 msg_reply.payload.memory.regions[msg_i].userspace_addr,
542                 msg.payload.memory.regions[msg_i].userspace_addr,
543                 msg_i, region_i);
544             msg_i++;
545         }
546     }
547     if (msg_i != fd_num) {
548         error_report("%s: postcopy reply not fully consumed "
549                      "%d vs %zd",
550                      __func__, msg_i, fd_num);
551         return -1;
552     }
553     /* Now we've registered this with the postcopy code, we ack to the client,
554      * because now we're in the position to be able to deal with any faults
555      * it generates.
556      */
557     /* TODO: Use this for failure cases as well with a bad value */
558     msg.hdr.size = sizeof(msg.payload.u64);
559     msg.payload.u64 = 0; /* OK */
560     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
561         return -1;
562     }
563 
564     return 0;
565 }
566 
567 static int vhost_user_set_mem_table(struct vhost_dev *dev,
568                                     struct vhost_memory *mem)
569 {
570     struct vhost_user *u = dev->opaque;
571     int fds[VHOST_MEMORY_MAX_NREGIONS];
572     size_t fd_num = 0;
573     bool do_postcopy = u->postcopy_listen && u->postcopy_fd.handler;
574     bool reply_supported = virtio_has_feature(dev->protocol_features,
575                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
576 
577     if (do_postcopy) {
578         /* Postcopy has enough differences that it's best done in it's own
579          * version
580          */
581         return vhost_user_set_mem_table_postcopy(dev, mem);
582     }
583 
584     VhostUserMsg msg = {
585         .hdr.flags = VHOST_USER_VERSION,
586     };
587 
588     if (reply_supported) {
589         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
590     }
591 
592     if (vhost_user_fill_set_mem_table_msg(u, dev, &msg, fds, &fd_num,
593                                           false) < 0) {
594         return -1;
595     }
596 
597     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
598         return -1;
599     }
600 
601     if (reply_supported) {
602         return process_message_reply(dev, &msg);
603     }
604 
605     return 0;
606 }
607 
608 static int vhost_user_set_vring_addr(struct vhost_dev *dev,
609                                      struct vhost_vring_addr *addr)
610 {
611     VhostUserMsg msg = {
612         .hdr.request = VHOST_USER_SET_VRING_ADDR,
613         .hdr.flags = VHOST_USER_VERSION,
614         .payload.addr = *addr,
615         .hdr.size = sizeof(msg.payload.addr),
616     };
617 
618     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
619         return -1;
620     }
621 
622     return 0;
623 }
624 
625 static int vhost_user_set_vring_endian(struct vhost_dev *dev,
626                                        struct vhost_vring_state *ring)
627 {
628     bool cross_endian = virtio_has_feature(dev->protocol_features,
629                                            VHOST_USER_PROTOCOL_F_CROSS_ENDIAN);
630     VhostUserMsg msg = {
631         .hdr.request = VHOST_USER_SET_VRING_ENDIAN,
632         .hdr.flags = VHOST_USER_VERSION,
633         .payload.state = *ring,
634         .hdr.size = sizeof(msg.payload.state),
635     };
636 
637     if (!cross_endian) {
638         error_report("vhost-user trying to send unhandled ioctl");
639         return -1;
640     }
641 
642     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
643         return -1;
644     }
645 
646     return 0;
647 }
648 
649 static int vhost_set_vring(struct vhost_dev *dev,
650                            unsigned long int request,
651                            struct vhost_vring_state *ring)
652 {
653     VhostUserMsg msg = {
654         .hdr.request = request,
655         .hdr.flags = VHOST_USER_VERSION,
656         .payload.state = *ring,
657         .hdr.size = sizeof(msg.payload.state),
658     };
659 
660     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
661         return -1;
662     }
663 
664     return 0;
665 }
666 
667 static int vhost_user_set_vring_num(struct vhost_dev *dev,
668                                     struct vhost_vring_state *ring)
669 {
670     return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
671 }
672 
673 static void vhost_user_host_notifier_restore(struct vhost_dev *dev,
674                                              int queue_idx)
675 {
676     struct vhost_user *u = dev->opaque;
677     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
678     VirtIODevice *vdev = dev->vdev;
679 
680     if (n->addr && !n->set) {
681         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true);
682         n->set = true;
683     }
684 }
685 
686 static void vhost_user_host_notifier_remove(struct vhost_dev *dev,
687                                             int queue_idx)
688 {
689     struct vhost_user *u = dev->opaque;
690     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
691     VirtIODevice *vdev = dev->vdev;
692 
693     if (n->addr && n->set) {
694         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
695         n->set = false;
696     }
697 }
698 
699 static int vhost_user_set_vring_base(struct vhost_dev *dev,
700                                      struct vhost_vring_state *ring)
701 {
702     vhost_user_host_notifier_restore(dev, ring->index);
703 
704     return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
705 }
706 
707 static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
708 {
709     int i;
710 
711     if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
712         return -1;
713     }
714 
715     for (i = 0; i < dev->nvqs; ++i) {
716         struct vhost_vring_state state = {
717             .index = dev->vq_index + i,
718             .num   = enable,
719         };
720 
721         vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
722     }
723 
724     return 0;
725 }
726 
727 static int vhost_user_get_vring_base(struct vhost_dev *dev,
728                                      struct vhost_vring_state *ring)
729 {
730     VhostUserMsg msg = {
731         .hdr.request = VHOST_USER_GET_VRING_BASE,
732         .hdr.flags = VHOST_USER_VERSION,
733         .payload.state = *ring,
734         .hdr.size = sizeof(msg.payload.state),
735     };
736 
737     vhost_user_host_notifier_remove(dev, ring->index);
738 
739     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
740         return -1;
741     }
742 
743     if (vhost_user_read(dev, &msg) < 0) {
744         return -1;
745     }
746 
747     if (msg.hdr.request != VHOST_USER_GET_VRING_BASE) {
748         error_report("Received unexpected msg type. Expected %d received %d",
749                      VHOST_USER_GET_VRING_BASE, msg.hdr.request);
750         return -1;
751     }
752 
753     if (msg.hdr.size != sizeof(msg.payload.state)) {
754         error_report("Received bad msg size.");
755         return -1;
756     }
757 
758     *ring = msg.payload.state;
759 
760     return 0;
761 }
762 
763 static int vhost_set_vring_file(struct vhost_dev *dev,
764                                 VhostUserRequest request,
765                                 struct vhost_vring_file *file)
766 {
767     int fds[VHOST_MEMORY_MAX_NREGIONS];
768     size_t fd_num = 0;
769     VhostUserMsg msg = {
770         .hdr.request = request,
771         .hdr.flags = VHOST_USER_VERSION,
772         .payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
773         .hdr.size = sizeof(msg.payload.u64),
774     };
775 
776     if (ioeventfd_enabled() && file->fd > 0) {
777         fds[fd_num++] = file->fd;
778     } else {
779         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
780     }
781 
782     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
783         return -1;
784     }
785 
786     return 0;
787 }
788 
789 static int vhost_user_set_vring_kick(struct vhost_dev *dev,
790                                      struct vhost_vring_file *file)
791 {
792     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
793 }
794 
795 static int vhost_user_set_vring_call(struct vhost_dev *dev,
796                                      struct vhost_vring_file *file)
797 {
798     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
799 }
800 
801 static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64)
802 {
803     VhostUserMsg msg = {
804         .hdr.request = request,
805         .hdr.flags = VHOST_USER_VERSION,
806         .payload.u64 = u64,
807         .hdr.size = sizeof(msg.payload.u64),
808     };
809 
810     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
811         return -1;
812     }
813 
814     return 0;
815 }
816 
817 static int vhost_user_set_features(struct vhost_dev *dev,
818                                    uint64_t features)
819 {
820     return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features);
821 }
822 
823 static int vhost_user_set_protocol_features(struct vhost_dev *dev,
824                                             uint64_t features)
825 {
826     return vhost_user_set_u64(dev, VHOST_USER_SET_PROTOCOL_FEATURES, features);
827 }
828 
829 static int vhost_user_get_u64(struct vhost_dev *dev, int request, uint64_t *u64)
830 {
831     VhostUserMsg msg = {
832         .hdr.request = request,
833         .hdr.flags = VHOST_USER_VERSION,
834     };
835 
836     if (vhost_user_one_time_request(request) && dev->vq_index != 0) {
837         return 0;
838     }
839 
840     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
841         return -1;
842     }
843 
844     if (vhost_user_read(dev, &msg) < 0) {
845         return -1;
846     }
847 
848     if (msg.hdr.request != request) {
849         error_report("Received unexpected msg type. Expected %d received %d",
850                      request, msg.hdr.request);
851         return -1;
852     }
853 
854     if (msg.hdr.size != sizeof(msg.payload.u64)) {
855         error_report("Received bad msg size.");
856         return -1;
857     }
858 
859     *u64 = msg.payload.u64;
860 
861     return 0;
862 }
863 
864 static int vhost_user_get_features(struct vhost_dev *dev, uint64_t *features)
865 {
866     return vhost_user_get_u64(dev, VHOST_USER_GET_FEATURES, features);
867 }
868 
869 static int vhost_user_set_owner(struct vhost_dev *dev)
870 {
871     VhostUserMsg msg = {
872         .hdr.request = VHOST_USER_SET_OWNER,
873         .hdr.flags = VHOST_USER_VERSION,
874     };
875 
876     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
877         return -1;
878     }
879 
880     return 0;
881 }
882 
883 static int vhost_user_reset_device(struct vhost_dev *dev)
884 {
885     VhostUserMsg msg = {
886         .hdr.flags = VHOST_USER_VERSION,
887     };
888 
889     msg.hdr.request = virtio_has_feature(dev->protocol_features,
890                                          VHOST_USER_PROTOCOL_F_RESET_DEVICE)
891         ? VHOST_USER_RESET_DEVICE
892         : VHOST_USER_RESET_OWNER;
893 
894     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
895         return -1;
896     }
897 
898     return 0;
899 }
900 
901 static int vhost_user_slave_handle_config_change(struct vhost_dev *dev)
902 {
903     int ret = -1;
904 
905     if (!dev->config_ops) {
906         return -1;
907     }
908 
909     if (dev->config_ops->vhost_dev_config_notifier) {
910         ret = dev->config_ops->vhost_dev_config_notifier(dev);
911     }
912 
913     return ret;
914 }
915 
916 static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev,
917                                                        VhostUserVringArea *area,
918                                                        int fd)
919 {
920     int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK;
921     size_t page_size = qemu_real_host_page_size;
922     struct vhost_user *u = dev->opaque;
923     VhostUserState *user = u->user;
924     VirtIODevice *vdev = dev->vdev;
925     VhostUserHostNotifier *n;
926     void *addr;
927     char *name;
928 
929     if (!virtio_has_feature(dev->protocol_features,
930                             VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) ||
931         vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) {
932         return -1;
933     }
934 
935     n = &user->notifier[queue_idx];
936 
937     if (n->addr) {
938         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
939         object_unparent(OBJECT(&n->mr));
940         munmap(n->addr, page_size);
941         n->addr = NULL;
942     }
943 
944     if (area->u64 & VHOST_USER_VRING_NOFD_MASK) {
945         return 0;
946     }
947 
948     /* Sanity check. */
949     if (area->size != page_size) {
950         return -1;
951     }
952 
953     addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
954                 fd, area->offset);
955     if (addr == MAP_FAILED) {
956         return -1;
957     }
958 
959     name = g_strdup_printf("vhost-user/host-notifier@%p mmaps[%d]",
960                            user, queue_idx);
961     memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name,
962                                       page_size, addr);
963     g_free(name);
964 
965     if (virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true)) {
966         munmap(addr, page_size);
967         return -1;
968     }
969 
970     n->addr = addr;
971     n->set = true;
972 
973     return 0;
974 }
975 
976 static void slave_read(void *opaque)
977 {
978     struct vhost_dev *dev = opaque;
979     struct vhost_user *u = dev->opaque;
980     VhostUserHeader hdr = { 0, };
981     VhostUserPayload payload = { 0, };
982     int size, ret = 0;
983     struct iovec iov;
984     struct msghdr msgh;
985     int fd[VHOST_USER_SLAVE_MAX_FDS];
986     char control[CMSG_SPACE(sizeof(fd))];
987     struct cmsghdr *cmsg;
988     int i, fdsize = 0;
989 
990     memset(&msgh, 0, sizeof(msgh));
991     msgh.msg_iov = &iov;
992     msgh.msg_iovlen = 1;
993     msgh.msg_control = control;
994     msgh.msg_controllen = sizeof(control);
995 
996     memset(fd, -1, sizeof(fd));
997 
998     /* Read header */
999     iov.iov_base = &hdr;
1000     iov.iov_len = VHOST_USER_HDR_SIZE;
1001 
1002     do {
1003         size = recvmsg(u->slave_fd, &msgh, 0);
1004     } while (size < 0 && (errno == EINTR || errno == EAGAIN));
1005 
1006     if (size != VHOST_USER_HDR_SIZE) {
1007         error_report("Failed to read from slave.");
1008         goto err;
1009     }
1010 
1011     if (msgh.msg_flags & MSG_CTRUNC) {
1012         error_report("Truncated message.");
1013         goto err;
1014     }
1015 
1016     for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;
1017          cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
1018             if (cmsg->cmsg_level == SOL_SOCKET &&
1019                 cmsg->cmsg_type == SCM_RIGHTS) {
1020                     fdsize = cmsg->cmsg_len - CMSG_LEN(0);
1021                     memcpy(fd, CMSG_DATA(cmsg), fdsize);
1022                     break;
1023             }
1024     }
1025 
1026     if (hdr.size > VHOST_USER_PAYLOAD_SIZE) {
1027         error_report("Failed to read msg header."
1028                 " Size %d exceeds the maximum %zu.", hdr.size,
1029                 VHOST_USER_PAYLOAD_SIZE);
1030         goto err;
1031     }
1032 
1033     /* Read payload */
1034     do {
1035         size = read(u->slave_fd, &payload, hdr.size);
1036     } while (size < 0 && (errno == EINTR || errno == EAGAIN));
1037 
1038     if (size != hdr.size) {
1039         error_report("Failed to read payload from slave.");
1040         goto err;
1041     }
1042 
1043     switch (hdr.request) {
1044     case VHOST_USER_SLAVE_IOTLB_MSG:
1045         ret = vhost_backend_handle_iotlb_msg(dev, &payload.iotlb);
1046         break;
1047     case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG :
1048         ret = vhost_user_slave_handle_config_change(dev);
1049         break;
1050     case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
1051         ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area,
1052                                                           fd[0]);
1053         break;
1054     default:
1055         error_report("Received unexpected msg type: %d.", hdr.request);
1056         ret = -EINVAL;
1057     }
1058 
1059     /* Close the remaining file descriptors. */
1060     for (i = 0; i < fdsize; i++) {
1061         if (fd[i] != -1) {
1062             close(fd[i]);
1063         }
1064     }
1065 
1066     /*
1067      * REPLY_ACK feature handling. Other reply types has to be managed
1068      * directly in their request handlers.
1069      */
1070     if (hdr.flags & VHOST_USER_NEED_REPLY_MASK) {
1071         struct iovec iovec[2];
1072 
1073 
1074         hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
1075         hdr.flags |= VHOST_USER_REPLY_MASK;
1076 
1077         payload.u64 = !!ret;
1078         hdr.size = sizeof(payload.u64);
1079 
1080         iovec[0].iov_base = &hdr;
1081         iovec[0].iov_len = VHOST_USER_HDR_SIZE;
1082         iovec[1].iov_base = &payload;
1083         iovec[1].iov_len = hdr.size;
1084 
1085         do {
1086             size = writev(u->slave_fd, iovec, ARRAY_SIZE(iovec));
1087         } while (size < 0 && (errno == EINTR || errno == EAGAIN));
1088 
1089         if (size != VHOST_USER_HDR_SIZE + hdr.size) {
1090             error_report("Failed to send msg reply to slave.");
1091             goto err;
1092         }
1093     }
1094 
1095     return;
1096 
1097 err:
1098     qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1099     close(u->slave_fd);
1100     u->slave_fd = -1;
1101     for (i = 0; i < fdsize; i++) {
1102         if (fd[i] != -1) {
1103             close(fd[i]);
1104         }
1105     }
1106     return;
1107 }
1108 
1109 static int vhost_setup_slave_channel(struct vhost_dev *dev)
1110 {
1111     VhostUserMsg msg = {
1112         .hdr.request = VHOST_USER_SET_SLAVE_REQ_FD,
1113         .hdr.flags = VHOST_USER_VERSION,
1114     };
1115     struct vhost_user *u = dev->opaque;
1116     int sv[2], ret = 0;
1117     bool reply_supported = virtio_has_feature(dev->protocol_features,
1118                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1119 
1120     if (!virtio_has_feature(dev->protocol_features,
1121                             VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
1122         return 0;
1123     }
1124 
1125     if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
1126         error_report("socketpair() failed");
1127         return -1;
1128     }
1129 
1130     u->slave_fd = sv[0];
1131     qemu_set_fd_handler(u->slave_fd, slave_read, NULL, dev);
1132 
1133     if (reply_supported) {
1134         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1135     }
1136 
1137     ret = vhost_user_write(dev, &msg, &sv[1], 1);
1138     if (ret) {
1139         goto out;
1140     }
1141 
1142     if (reply_supported) {
1143         ret = process_message_reply(dev, &msg);
1144     }
1145 
1146 out:
1147     close(sv[1]);
1148     if (ret) {
1149         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1150         close(u->slave_fd);
1151         u->slave_fd = -1;
1152     }
1153 
1154     return ret;
1155 }
1156 
1157 #ifdef CONFIG_LINUX
1158 /*
1159  * Called back from the postcopy fault thread when a fault is received on our
1160  * ufd.
1161  * TODO: This is Linux specific
1162  */
1163 static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
1164                                              void *ufd)
1165 {
1166     struct vhost_dev *dev = pcfd->data;
1167     struct vhost_user *u = dev->opaque;
1168     struct uffd_msg *msg = ufd;
1169     uint64_t faultaddr = msg->arg.pagefault.address;
1170     RAMBlock *rb = NULL;
1171     uint64_t rb_offset;
1172     int i;
1173 
1174     trace_vhost_user_postcopy_fault_handler(pcfd->idstr, faultaddr,
1175                                             dev->mem->nregions);
1176     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1177         trace_vhost_user_postcopy_fault_handler_loop(i,
1178                 u->postcopy_client_bases[i], dev->mem->regions[i].memory_size);
1179         if (faultaddr >= u->postcopy_client_bases[i]) {
1180             /* Ofset of the fault address in the vhost region */
1181             uint64_t region_offset = faultaddr - u->postcopy_client_bases[i];
1182             if (region_offset < dev->mem->regions[i].memory_size) {
1183                 rb_offset = region_offset + u->region_rb_offset[i];
1184                 trace_vhost_user_postcopy_fault_handler_found(i,
1185                         region_offset, rb_offset);
1186                 rb = u->region_rb[i];
1187                 return postcopy_request_shared_page(pcfd, rb, faultaddr,
1188                                                     rb_offset);
1189             }
1190         }
1191     }
1192     error_report("%s: Failed to find region for fault %" PRIx64,
1193                  __func__, faultaddr);
1194     return -1;
1195 }
1196 
1197 static int vhost_user_postcopy_waker(struct PostCopyFD *pcfd, RAMBlock *rb,
1198                                      uint64_t offset)
1199 {
1200     struct vhost_dev *dev = pcfd->data;
1201     struct vhost_user *u = dev->opaque;
1202     int i;
1203 
1204     trace_vhost_user_postcopy_waker(qemu_ram_get_idstr(rb), offset);
1205 
1206     if (!u) {
1207         return 0;
1208     }
1209     /* Translate the offset into an address in the clients address space */
1210     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1211         if (u->region_rb[i] == rb &&
1212             offset >= u->region_rb_offset[i] &&
1213             offset < (u->region_rb_offset[i] +
1214                       dev->mem->regions[i].memory_size)) {
1215             uint64_t client_addr = (offset - u->region_rb_offset[i]) +
1216                                    u->postcopy_client_bases[i];
1217             trace_vhost_user_postcopy_waker_found(client_addr);
1218             return postcopy_wake_shared(pcfd, client_addr, rb);
1219         }
1220     }
1221 
1222     trace_vhost_user_postcopy_waker_nomatch(qemu_ram_get_idstr(rb), offset);
1223     return 0;
1224 }
1225 #endif
1226 
1227 /*
1228  * Called at the start of an inbound postcopy on reception of the
1229  * 'advise' command.
1230  */
1231 static int vhost_user_postcopy_advise(struct vhost_dev *dev, Error **errp)
1232 {
1233 #ifdef CONFIG_LINUX
1234     struct vhost_user *u = dev->opaque;
1235     CharBackend *chr = u->user->chr;
1236     int ufd;
1237     VhostUserMsg msg = {
1238         .hdr.request = VHOST_USER_POSTCOPY_ADVISE,
1239         .hdr.flags = VHOST_USER_VERSION,
1240     };
1241 
1242     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1243         error_setg(errp, "Failed to send postcopy_advise to vhost");
1244         return -1;
1245     }
1246 
1247     if (vhost_user_read(dev, &msg) < 0) {
1248         error_setg(errp, "Failed to get postcopy_advise reply from vhost");
1249         return -1;
1250     }
1251 
1252     if (msg.hdr.request != VHOST_USER_POSTCOPY_ADVISE) {
1253         error_setg(errp, "Unexpected msg type. Expected %d received %d",
1254                      VHOST_USER_POSTCOPY_ADVISE, msg.hdr.request);
1255         return -1;
1256     }
1257 
1258     if (msg.hdr.size) {
1259         error_setg(errp, "Received bad msg size.");
1260         return -1;
1261     }
1262     ufd = qemu_chr_fe_get_msgfd(chr);
1263     if (ufd < 0) {
1264         error_setg(errp, "%s: Failed to get ufd", __func__);
1265         return -1;
1266     }
1267     qemu_set_nonblock(ufd);
1268 
1269     /* register ufd with userfault thread */
1270     u->postcopy_fd.fd = ufd;
1271     u->postcopy_fd.data = dev;
1272     u->postcopy_fd.handler = vhost_user_postcopy_fault_handler;
1273     u->postcopy_fd.waker = vhost_user_postcopy_waker;
1274     u->postcopy_fd.idstr = "vhost-user"; /* Need to find unique name */
1275     postcopy_register_shared_ufd(&u->postcopy_fd);
1276     return 0;
1277 #else
1278     error_setg(errp, "Postcopy not supported on non-Linux systems");
1279     return -1;
1280 #endif
1281 }
1282 
1283 /*
1284  * Called at the switch to postcopy on reception of the 'listen' command.
1285  */
1286 static int vhost_user_postcopy_listen(struct vhost_dev *dev, Error **errp)
1287 {
1288     struct vhost_user *u = dev->opaque;
1289     int ret;
1290     VhostUserMsg msg = {
1291         .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
1292         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1293     };
1294     u->postcopy_listen = true;
1295     trace_vhost_user_postcopy_listen();
1296     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1297         error_setg(errp, "Failed to send postcopy_listen to vhost");
1298         return -1;
1299     }
1300 
1301     ret = process_message_reply(dev, &msg);
1302     if (ret) {
1303         error_setg(errp, "Failed to receive reply to postcopy_listen");
1304         return ret;
1305     }
1306 
1307     return 0;
1308 }
1309 
1310 /*
1311  * Called at the end of postcopy
1312  */
1313 static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
1314 {
1315     VhostUserMsg msg = {
1316         .hdr.request = VHOST_USER_POSTCOPY_END,
1317         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1318     };
1319     int ret;
1320     struct vhost_user *u = dev->opaque;
1321 
1322     trace_vhost_user_postcopy_end_entry();
1323     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1324         error_setg(errp, "Failed to send postcopy_end to vhost");
1325         return -1;
1326     }
1327 
1328     ret = process_message_reply(dev, &msg);
1329     if (ret) {
1330         error_setg(errp, "Failed to receive reply to postcopy_end");
1331         return ret;
1332     }
1333     postcopy_unregister_shared_ufd(&u->postcopy_fd);
1334     close(u->postcopy_fd.fd);
1335     u->postcopy_fd.handler = NULL;
1336 
1337     trace_vhost_user_postcopy_end_exit();
1338 
1339     return 0;
1340 }
1341 
1342 static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
1343                                         void *opaque)
1344 {
1345     struct PostcopyNotifyData *pnd = opaque;
1346     struct vhost_user *u = container_of(notifier, struct vhost_user,
1347                                          postcopy_notifier);
1348     struct vhost_dev *dev = u->dev;
1349 
1350     switch (pnd->reason) {
1351     case POSTCOPY_NOTIFY_PROBE:
1352         if (!virtio_has_feature(dev->protocol_features,
1353                                 VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
1354             /* TODO: Get the device name into this error somehow */
1355             error_setg(pnd->errp,
1356                        "vhost-user backend not capable of postcopy");
1357             return -ENOENT;
1358         }
1359         break;
1360 
1361     case POSTCOPY_NOTIFY_INBOUND_ADVISE:
1362         return vhost_user_postcopy_advise(dev, pnd->errp);
1363 
1364     case POSTCOPY_NOTIFY_INBOUND_LISTEN:
1365         return vhost_user_postcopy_listen(dev, pnd->errp);
1366 
1367     case POSTCOPY_NOTIFY_INBOUND_END:
1368         return vhost_user_postcopy_end(dev, pnd->errp);
1369 
1370     default:
1371         /* We ignore notifications we don't know */
1372         break;
1373     }
1374 
1375     return 0;
1376 }
1377 
1378 static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque)
1379 {
1380     uint64_t features, protocol_features;
1381     struct vhost_user *u;
1382     int err;
1383 
1384     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1385 
1386     u = g_new0(struct vhost_user, 1);
1387     u->user = opaque;
1388     u->slave_fd = -1;
1389     u->dev = dev;
1390     dev->opaque = u;
1391 
1392     err = vhost_user_get_features(dev, &features);
1393     if (err < 0) {
1394         return err;
1395     }
1396 
1397     if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
1398         dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
1399 
1400         err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
1401                                  &protocol_features);
1402         if (err < 0) {
1403             return err;
1404         }
1405 
1406         dev->protocol_features =
1407             protocol_features & VHOST_USER_PROTOCOL_FEATURE_MASK;
1408 
1409         if (!dev->config_ops || !dev->config_ops->vhost_dev_config_notifier) {
1410             /* Don't acknowledge CONFIG feature if device doesn't support it */
1411             dev->protocol_features &= ~(1ULL << VHOST_USER_PROTOCOL_F_CONFIG);
1412         } else if (!(protocol_features &
1413                     (1ULL << VHOST_USER_PROTOCOL_F_CONFIG))) {
1414             error_report("Device expects VHOST_USER_PROTOCOL_F_CONFIG "
1415                     "but backend does not support it.");
1416             return -1;
1417         }
1418 
1419         err = vhost_user_set_protocol_features(dev, dev->protocol_features);
1420         if (err < 0) {
1421             return err;
1422         }
1423 
1424         /* query the max queues we support if backend supports Multiple Queue */
1425         if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
1426             err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
1427                                      &dev->max_queues);
1428             if (err < 0) {
1429                 return err;
1430             }
1431         }
1432 
1433         if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) &&
1434                 !(virtio_has_feature(dev->protocol_features,
1435                     VHOST_USER_PROTOCOL_F_SLAVE_REQ) &&
1436                  virtio_has_feature(dev->protocol_features,
1437                     VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1438             error_report("IOMMU support requires reply-ack and "
1439                          "slave-req protocol features.");
1440             return -1;
1441         }
1442     }
1443 
1444     if (dev->migration_blocker == NULL &&
1445         !virtio_has_feature(dev->protocol_features,
1446                             VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
1447         error_setg(&dev->migration_blocker,
1448                    "Migration disabled: vhost-user backend lacks "
1449                    "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
1450     }
1451 
1452     if (dev->vq_index == 0) {
1453         err = vhost_setup_slave_channel(dev);
1454         if (err < 0) {
1455             return err;
1456         }
1457     }
1458 
1459     u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
1460     postcopy_add_notifier(&u->postcopy_notifier);
1461 
1462     return 0;
1463 }
1464 
1465 static int vhost_user_backend_cleanup(struct vhost_dev *dev)
1466 {
1467     struct vhost_user *u;
1468 
1469     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1470 
1471     u = dev->opaque;
1472     if (u->postcopy_notifier.notify) {
1473         postcopy_remove_notifier(&u->postcopy_notifier);
1474         u->postcopy_notifier.notify = NULL;
1475     }
1476     u->postcopy_listen = false;
1477     if (u->postcopy_fd.handler) {
1478         postcopy_unregister_shared_ufd(&u->postcopy_fd);
1479         close(u->postcopy_fd.fd);
1480         u->postcopy_fd.handler = NULL;
1481     }
1482     if (u->slave_fd >= 0) {
1483         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1484         close(u->slave_fd);
1485         u->slave_fd = -1;
1486     }
1487     g_free(u->region_rb);
1488     u->region_rb = NULL;
1489     g_free(u->region_rb_offset);
1490     u->region_rb_offset = NULL;
1491     u->region_rb_len = 0;
1492     g_free(u);
1493     dev->opaque = 0;
1494 
1495     return 0;
1496 }
1497 
1498 static int vhost_user_get_vq_index(struct vhost_dev *dev, int idx)
1499 {
1500     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
1501 
1502     return idx;
1503 }
1504 
1505 static int vhost_user_memslots_limit(struct vhost_dev *dev)
1506 {
1507     return VHOST_MEMORY_MAX_NREGIONS;
1508 }
1509 
1510 static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
1511 {
1512     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1513 
1514     return virtio_has_feature(dev->protocol_features,
1515                               VHOST_USER_PROTOCOL_F_LOG_SHMFD);
1516 }
1517 
1518 static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
1519 {
1520     VhostUserMsg msg = { };
1521 
1522     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1523 
1524     /* If guest supports GUEST_ANNOUNCE do nothing */
1525     if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {
1526         return 0;
1527     }
1528 
1529     /* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
1530     if (virtio_has_feature(dev->protocol_features,
1531                            VHOST_USER_PROTOCOL_F_RARP)) {
1532         msg.hdr.request = VHOST_USER_SEND_RARP;
1533         msg.hdr.flags = VHOST_USER_VERSION;
1534         memcpy((char *)&msg.payload.u64, mac_addr, 6);
1535         msg.hdr.size = sizeof(msg.payload.u64);
1536 
1537         return vhost_user_write(dev, &msg, NULL, 0);
1538     }
1539     return -1;
1540 }
1541 
1542 static bool vhost_user_can_merge(struct vhost_dev *dev,
1543                                  uint64_t start1, uint64_t size1,
1544                                  uint64_t start2, uint64_t size2)
1545 {
1546     ram_addr_t offset;
1547     int mfd, rfd;
1548     MemoryRegion *mr;
1549 
1550     mr = memory_region_from_host((void *)(uintptr_t)start1, &offset);
1551     mfd = memory_region_get_fd(mr);
1552 
1553     mr = memory_region_from_host((void *)(uintptr_t)start2, &offset);
1554     rfd = memory_region_get_fd(mr);
1555 
1556     return mfd == rfd;
1557 }
1558 
1559 static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu)
1560 {
1561     VhostUserMsg msg;
1562     bool reply_supported = virtio_has_feature(dev->protocol_features,
1563                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1564 
1565     if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))) {
1566         return 0;
1567     }
1568 
1569     msg.hdr.request = VHOST_USER_NET_SET_MTU;
1570     msg.payload.u64 = mtu;
1571     msg.hdr.size = sizeof(msg.payload.u64);
1572     msg.hdr.flags = VHOST_USER_VERSION;
1573     if (reply_supported) {
1574         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1575     }
1576 
1577     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1578         return -1;
1579     }
1580 
1581     /* If reply_ack supported, slave has to ack specified MTU is valid */
1582     if (reply_supported) {
1583         return process_message_reply(dev, &msg);
1584     }
1585 
1586     return 0;
1587 }
1588 
1589 static int vhost_user_send_device_iotlb_msg(struct vhost_dev *dev,
1590                                             struct vhost_iotlb_msg *imsg)
1591 {
1592     VhostUserMsg msg = {
1593         .hdr.request = VHOST_USER_IOTLB_MSG,
1594         .hdr.size = sizeof(msg.payload.iotlb),
1595         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1596         .payload.iotlb = *imsg,
1597     };
1598 
1599     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1600         return -EFAULT;
1601     }
1602 
1603     return process_message_reply(dev, &msg);
1604 }
1605 
1606 
1607 static void vhost_user_set_iotlb_callback(struct vhost_dev *dev, int enabled)
1608 {
1609     /* No-op as the receive channel is not dedicated to IOTLB messages. */
1610 }
1611 
1612 static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
1613                                  uint32_t config_len)
1614 {
1615     VhostUserMsg msg = {
1616         .hdr.request = VHOST_USER_GET_CONFIG,
1617         .hdr.flags = VHOST_USER_VERSION,
1618         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + config_len,
1619     };
1620 
1621     if (!virtio_has_feature(dev->protocol_features,
1622                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1623         return -1;
1624     }
1625 
1626     if (config_len > VHOST_USER_MAX_CONFIG_SIZE) {
1627         return -1;
1628     }
1629 
1630     msg.payload.config.offset = 0;
1631     msg.payload.config.size = config_len;
1632     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1633         return -1;
1634     }
1635 
1636     if (vhost_user_read(dev, &msg) < 0) {
1637         return -1;
1638     }
1639 
1640     if (msg.hdr.request != VHOST_USER_GET_CONFIG) {
1641         error_report("Received unexpected msg type. Expected %d received %d",
1642                      VHOST_USER_GET_CONFIG, msg.hdr.request);
1643         return -1;
1644     }
1645 
1646     if (msg.hdr.size != VHOST_USER_CONFIG_HDR_SIZE + config_len) {
1647         error_report("Received bad msg size.");
1648         return -1;
1649     }
1650 
1651     memcpy(config, msg.payload.config.region, config_len);
1652 
1653     return 0;
1654 }
1655 
1656 static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *data,
1657                                  uint32_t offset, uint32_t size, uint32_t flags)
1658 {
1659     uint8_t *p;
1660     bool reply_supported = virtio_has_feature(dev->protocol_features,
1661                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1662 
1663     VhostUserMsg msg = {
1664         .hdr.request = VHOST_USER_SET_CONFIG,
1665         .hdr.flags = VHOST_USER_VERSION,
1666         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + size,
1667     };
1668 
1669     if (!virtio_has_feature(dev->protocol_features,
1670                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1671         return -1;
1672     }
1673 
1674     if (reply_supported) {
1675         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1676     }
1677 
1678     if (size > VHOST_USER_MAX_CONFIG_SIZE) {
1679         return -1;
1680     }
1681 
1682     msg.payload.config.offset = offset,
1683     msg.payload.config.size = size,
1684     msg.payload.config.flags = flags,
1685     p = msg.payload.config.region;
1686     memcpy(p, data, size);
1687 
1688     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1689         return -1;
1690     }
1691 
1692     if (reply_supported) {
1693         return process_message_reply(dev, &msg);
1694     }
1695 
1696     return 0;
1697 }
1698 
1699 static int vhost_user_crypto_create_session(struct vhost_dev *dev,
1700                                             void *session_info,
1701                                             uint64_t *session_id)
1702 {
1703     bool crypto_session = virtio_has_feature(dev->protocol_features,
1704                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1705     CryptoDevBackendSymSessionInfo *sess_info = session_info;
1706     VhostUserMsg msg = {
1707         .hdr.request = VHOST_USER_CREATE_CRYPTO_SESSION,
1708         .hdr.flags = VHOST_USER_VERSION,
1709         .hdr.size = sizeof(msg.payload.session),
1710     };
1711 
1712     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1713 
1714     if (!crypto_session) {
1715         error_report("vhost-user trying to send unhandled ioctl");
1716         return -1;
1717     }
1718 
1719     memcpy(&msg.payload.session.session_setup_data, sess_info,
1720               sizeof(CryptoDevBackendSymSessionInfo));
1721     if (sess_info->key_len) {
1722         memcpy(&msg.payload.session.key, sess_info->cipher_key,
1723                sess_info->key_len);
1724     }
1725     if (sess_info->auth_key_len > 0) {
1726         memcpy(&msg.payload.session.auth_key, sess_info->auth_key,
1727                sess_info->auth_key_len);
1728     }
1729     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1730         error_report("vhost_user_write() return -1, create session failed");
1731         return -1;
1732     }
1733 
1734     if (vhost_user_read(dev, &msg) < 0) {
1735         error_report("vhost_user_read() return -1, create session failed");
1736         return -1;
1737     }
1738 
1739     if (msg.hdr.request != VHOST_USER_CREATE_CRYPTO_SESSION) {
1740         error_report("Received unexpected msg type. Expected %d received %d",
1741                      VHOST_USER_CREATE_CRYPTO_SESSION, msg.hdr.request);
1742         return -1;
1743     }
1744 
1745     if (msg.hdr.size != sizeof(msg.payload.session)) {
1746         error_report("Received bad msg size.");
1747         return -1;
1748     }
1749 
1750     if (msg.payload.session.session_id < 0) {
1751         error_report("Bad session id: %" PRId64 "",
1752                               msg.payload.session.session_id);
1753         return -1;
1754     }
1755     *session_id = msg.payload.session.session_id;
1756 
1757     return 0;
1758 }
1759 
1760 static int
1761 vhost_user_crypto_close_session(struct vhost_dev *dev, uint64_t session_id)
1762 {
1763     bool crypto_session = virtio_has_feature(dev->protocol_features,
1764                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1765     VhostUserMsg msg = {
1766         .hdr.request = VHOST_USER_CLOSE_CRYPTO_SESSION,
1767         .hdr.flags = VHOST_USER_VERSION,
1768         .hdr.size = sizeof(msg.payload.u64),
1769     };
1770     msg.payload.u64 = session_id;
1771 
1772     if (!crypto_session) {
1773         error_report("vhost-user trying to send unhandled ioctl");
1774         return -1;
1775     }
1776 
1777     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1778         error_report("vhost_user_write() return -1, close session failed");
1779         return -1;
1780     }
1781 
1782     return 0;
1783 }
1784 
1785 static bool vhost_user_mem_section_filter(struct vhost_dev *dev,
1786                                           MemoryRegionSection *section)
1787 {
1788     bool result;
1789 
1790     result = memory_region_get_fd(section->mr) >= 0;
1791 
1792     return result;
1793 }
1794 
1795 static int vhost_user_get_inflight_fd(struct vhost_dev *dev,
1796                                       uint16_t queue_size,
1797                                       struct vhost_inflight *inflight)
1798 {
1799     void *addr;
1800     int fd;
1801     struct vhost_user *u = dev->opaque;
1802     CharBackend *chr = u->user->chr;
1803     VhostUserMsg msg = {
1804         .hdr.request = VHOST_USER_GET_INFLIGHT_FD,
1805         .hdr.flags = VHOST_USER_VERSION,
1806         .payload.inflight.num_queues = dev->nvqs,
1807         .payload.inflight.queue_size = queue_size,
1808         .hdr.size = sizeof(msg.payload.inflight),
1809     };
1810 
1811     if (!virtio_has_feature(dev->protocol_features,
1812                             VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
1813         return 0;
1814     }
1815 
1816     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1817         return -1;
1818     }
1819 
1820     if (vhost_user_read(dev, &msg) < 0) {
1821         return -1;
1822     }
1823 
1824     if (msg.hdr.request != VHOST_USER_GET_INFLIGHT_FD) {
1825         error_report("Received unexpected msg type. "
1826                      "Expected %d received %d",
1827                      VHOST_USER_GET_INFLIGHT_FD, msg.hdr.request);
1828         return -1;
1829     }
1830 
1831     if (msg.hdr.size != sizeof(msg.payload.inflight)) {
1832         error_report("Received bad msg size.");
1833         return -1;
1834     }
1835 
1836     if (!msg.payload.inflight.mmap_size) {
1837         return 0;
1838     }
1839 
1840     fd = qemu_chr_fe_get_msgfd(chr);
1841     if (fd < 0) {
1842         error_report("Failed to get mem fd");
1843         return -1;
1844     }
1845 
1846     addr = mmap(0, msg.payload.inflight.mmap_size, PROT_READ | PROT_WRITE,
1847                 MAP_SHARED, fd, msg.payload.inflight.mmap_offset);
1848 
1849     if (addr == MAP_FAILED) {
1850         error_report("Failed to mmap mem fd");
1851         close(fd);
1852         return -1;
1853     }
1854 
1855     inflight->addr = addr;
1856     inflight->fd = fd;
1857     inflight->size = msg.payload.inflight.mmap_size;
1858     inflight->offset = msg.payload.inflight.mmap_offset;
1859     inflight->queue_size = queue_size;
1860 
1861     return 0;
1862 }
1863 
1864 static int vhost_user_set_inflight_fd(struct vhost_dev *dev,
1865                                       struct vhost_inflight *inflight)
1866 {
1867     VhostUserMsg msg = {
1868         .hdr.request = VHOST_USER_SET_INFLIGHT_FD,
1869         .hdr.flags = VHOST_USER_VERSION,
1870         .payload.inflight.mmap_size = inflight->size,
1871         .payload.inflight.mmap_offset = inflight->offset,
1872         .payload.inflight.num_queues = dev->nvqs,
1873         .payload.inflight.queue_size = inflight->queue_size,
1874         .hdr.size = sizeof(msg.payload.inflight),
1875     };
1876 
1877     if (!virtio_has_feature(dev->protocol_features,
1878                             VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
1879         return 0;
1880     }
1881 
1882     if (vhost_user_write(dev, &msg, &inflight->fd, 1) < 0) {
1883         return -1;
1884     }
1885 
1886     return 0;
1887 }
1888 
1889 bool vhost_user_init(VhostUserState *user, CharBackend *chr, Error **errp)
1890 {
1891     if (user->chr) {
1892         error_setg(errp, "Cannot initialize vhost-user state");
1893         return false;
1894     }
1895     user->chr = chr;
1896     return true;
1897 }
1898 
1899 void vhost_user_cleanup(VhostUserState *user)
1900 {
1901     int i;
1902 
1903     if (!user->chr) {
1904         return;
1905     }
1906 
1907     for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1908         if (user->notifier[i].addr) {
1909             object_unparent(OBJECT(&user->notifier[i].mr));
1910             munmap(user->notifier[i].addr, qemu_real_host_page_size);
1911             user->notifier[i].addr = NULL;
1912         }
1913     }
1914     user->chr = NULL;
1915 }
1916 
1917 const VhostOps user_ops = {
1918         .backend_type = VHOST_BACKEND_TYPE_USER,
1919         .vhost_backend_init = vhost_user_backend_init,
1920         .vhost_backend_cleanup = vhost_user_backend_cleanup,
1921         .vhost_backend_memslots_limit = vhost_user_memslots_limit,
1922         .vhost_set_log_base = vhost_user_set_log_base,
1923         .vhost_set_mem_table = vhost_user_set_mem_table,
1924         .vhost_set_vring_addr = vhost_user_set_vring_addr,
1925         .vhost_set_vring_endian = vhost_user_set_vring_endian,
1926         .vhost_set_vring_num = vhost_user_set_vring_num,
1927         .vhost_set_vring_base = vhost_user_set_vring_base,
1928         .vhost_get_vring_base = vhost_user_get_vring_base,
1929         .vhost_set_vring_kick = vhost_user_set_vring_kick,
1930         .vhost_set_vring_call = vhost_user_set_vring_call,
1931         .vhost_set_features = vhost_user_set_features,
1932         .vhost_get_features = vhost_user_get_features,
1933         .vhost_set_owner = vhost_user_set_owner,
1934         .vhost_reset_device = vhost_user_reset_device,
1935         .vhost_get_vq_index = vhost_user_get_vq_index,
1936         .vhost_set_vring_enable = vhost_user_set_vring_enable,
1937         .vhost_requires_shm_log = vhost_user_requires_shm_log,
1938         .vhost_migration_done = vhost_user_migration_done,
1939         .vhost_backend_can_merge = vhost_user_can_merge,
1940         .vhost_net_set_mtu = vhost_user_net_set_mtu,
1941         .vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
1942         .vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
1943         .vhost_get_config = vhost_user_get_config,
1944         .vhost_set_config = vhost_user_set_config,
1945         .vhost_crypto_create_session = vhost_user_crypto_create_session,
1946         .vhost_crypto_close_session = vhost_user_crypto_close_session,
1947         .vhost_backend_mem_section_filter = vhost_user_mem_section_filter,
1948         .vhost_get_inflight_fd = vhost_user_get_inflight_fd,
1949         .vhost_set_inflight_fd = vhost_user_set_inflight_fd,
1950 };
1951