xref: /openbmc/qemu/hw/virtio/vhost-user.c (revision 966f2ec3)
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/sockets.h"
22 #include "sysemu/cryptodev.h"
23 #include "migration/migration.h"
24 #include "migration/postcopy-ram.h"
25 #include "trace.h"
26 
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <sys/un.h>
30 #include <linux/vhost.h>
31 #include <linux/userfaultfd.h>
32 
33 #define VHOST_MEMORY_MAX_NREGIONS    8
34 #define VHOST_USER_F_PROTOCOL_FEATURES 30
35 #define VHOST_USER_SLAVE_MAX_FDS     8
36 
37 /*
38  * Maximum size of virtio device config space
39  */
40 #define VHOST_USER_MAX_CONFIG_SIZE 256
41 
42 enum VhostUserProtocolFeature {
43     VHOST_USER_PROTOCOL_F_MQ = 0,
44     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
45     VHOST_USER_PROTOCOL_F_RARP = 2,
46     VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
47     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
48     VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
49     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
50     VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
51     VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
52     VHOST_USER_PROTOCOL_F_CONFIG = 9,
53     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
54     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
55     VHOST_USER_PROTOCOL_F_MAX
56 };
57 
58 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
59 
60 typedef enum VhostUserRequest {
61     VHOST_USER_NONE = 0,
62     VHOST_USER_GET_FEATURES = 1,
63     VHOST_USER_SET_FEATURES = 2,
64     VHOST_USER_SET_OWNER = 3,
65     VHOST_USER_RESET_OWNER = 4,
66     VHOST_USER_SET_MEM_TABLE = 5,
67     VHOST_USER_SET_LOG_BASE = 6,
68     VHOST_USER_SET_LOG_FD = 7,
69     VHOST_USER_SET_VRING_NUM = 8,
70     VHOST_USER_SET_VRING_ADDR = 9,
71     VHOST_USER_SET_VRING_BASE = 10,
72     VHOST_USER_GET_VRING_BASE = 11,
73     VHOST_USER_SET_VRING_KICK = 12,
74     VHOST_USER_SET_VRING_CALL = 13,
75     VHOST_USER_SET_VRING_ERR = 14,
76     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
77     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
78     VHOST_USER_GET_QUEUE_NUM = 17,
79     VHOST_USER_SET_VRING_ENABLE = 18,
80     VHOST_USER_SEND_RARP = 19,
81     VHOST_USER_NET_SET_MTU = 20,
82     VHOST_USER_SET_SLAVE_REQ_FD = 21,
83     VHOST_USER_IOTLB_MSG = 22,
84     VHOST_USER_SET_VRING_ENDIAN = 23,
85     VHOST_USER_GET_CONFIG = 24,
86     VHOST_USER_SET_CONFIG = 25,
87     VHOST_USER_CREATE_CRYPTO_SESSION = 26,
88     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
89     VHOST_USER_POSTCOPY_ADVISE  = 28,
90     VHOST_USER_POSTCOPY_LISTEN  = 29,
91     VHOST_USER_POSTCOPY_END     = 30,
92     VHOST_USER_MAX
93 } VhostUserRequest;
94 
95 typedef enum VhostUserSlaveRequest {
96     VHOST_USER_SLAVE_NONE = 0,
97     VHOST_USER_SLAVE_IOTLB_MSG = 1,
98     VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
99     VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
100     VHOST_USER_SLAVE_MAX
101 }  VhostUserSlaveRequest;
102 
103 typedef struct VhostUserMemoryRegion {
104     uint64_t guest_phys_addr;
105     uint64_t memory_size;
106     uint64_t userspace_addr;
107     uint64_t mmap_offset;
108 } VhostUserMemoryRegion;
109 
110 typedef struct VhostUserMemory {
111     uint32_t nregions;
112     uint32_t padding;
113     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
114 } VhostUserMemory;
115 
116 typedef struct VhostUserLog {
117     uint64_t mmap_size;
118     uint64_t mmap_offset;
119 } VhostUserLog;
120 
121 typedef struct VhostUserConfig {
122     uint32_t offset;
123     uint32_t size;
124     uint32_t flags;
125     uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
126 } VhostUserConfig;
127 
128 #define VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN    512
129 #define VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN  64
130 
131 typedef struct VhostUserCryptoSession {
132     /* session id for success, -1 on errors */
133     int64_t session_id;
134     CryptoDevBackendSymSessionInfo session_setup_data;
135     uint8_t key[VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN];
136     uint8_t auth_key[VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN];
137 } VhostUserCryptoSession;
138 
139 static VhostUserConfig c __attribute__ ((unused));
140 #define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
141                                    + sizeof(c.size) \
142                                    + sizeof(c.flags))
143 
144 typedef struct VhostUserVringArea {
145     uint64_t u64;
146     uint64_t size;
147     uint64_t offset;
148 } VhostUserVringArea;
149 
150 typedef struct {
151     VhostUserRequest request;
152 
153 #define VHOST_USER_VERSION_MASK     (0x3)
154 #define VHOST_USER_REPLY_MASK       (0x1<<2)
155 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
156     uint32_t flags;
157     uint32_t size; /* the following payload size */
158 } QEMU_PACKED VhostUserHeader;
159 
160 typedef union {
161 #define VHOST_USER_VRING_IDX_MASK   (0xff)
162 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
163         uint64_t u64;
164         struct vhost_vring_state state;
165         struct vhost_vring_addr addr;
166         VhostUserMemory memory;
167         VhostUserLog log;
168         struct vhost_iotlb_msg iotlb;
169         VhostUserConfig config;
170         VhostUserCryptoSession session;
171         VhostUserVringArea area;
172 } VhostUserPayload;
173 
174 typedef struct VhostUserMsg {
175     VhostUserHeader hdr;
176     VhostUserPayload payload;
177 } QEMU_PACKED VhostUserMsg;
178 
179 static VhostUserMsg m __attribute__ ((unused));
180 #define VHOST_USER_HDR_SIZE (sizeof(VhostUserHeader))
181 
182 #define VHOST_USER_PAYLOAD_SIZE (sizeof(VhostUserPayload))
183 
184 /* The version of the protocol we support */
185 #define VHOST_USER_VERSION    (0x1)
186 
187 struct vhost_user {
188     struct vhost_dev *dev;
189     /* Shared between vhost devs of the same virtio device */
190     VhostUserState *user;
191     int slave_fd;
192     NotifierWithReturn postcopy_notifier;
193     struct PostCopyFD  postcopy_fd;
194     uint64_t           postcopy_client_bases[VHOST_MEMORY_MAX_NREGIONS];
195     /* Length of the region_rb and region_rb_offset arrays */
196     size_t             region_rb_len;
197     /* RAMBlock associated with a given region */
198     RAMBlock         **region_rb;
199     /* The offset from the start of the RAMBlock to the start of the
200      * vhost region.
201      */
202     ram_addr_t        *region_rb_offset;
203 
204     /* True once we've entered postcopy_listen */
205     bool               postcopy_listen;
206 };
207 
208 static bool ioeventfd_enabled(void)
209 {
210     return kvm_enabled() && kvm_eventfds_enabled();
211 }
212 
213 static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
214 {
215     struct vhost_user *u = dev->opaque;
216     CharBackend *chr = u->user->chr;
217     uint8_t *p = (uint8_t *) msg;
218     int r, size = VHOST_USER_HDR_SIZE;
219 
220     r = qemu_chr_fe_read_all(chr, p, size);
221     if (r != size) {
222         error_report("Failed to read msg header. Read %d instead of %d."
223                      " Original request %d.", r, size, msg->hdr.request);
224         goto fail;
225     }
226 
227     /* validate received flags */
228     if (msg->hdr.flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
229         error_report("Failed to read msg header."
230                 " Flags 0x%x instead of 0x%x.", msg->hdr.flags,
231                 VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
232         goto fail;
233     }
234 
235     /* validate message size is sane */
236     if (msg->hdr.size > VHOST_USER_PAYLOAD_SIZE) {
237         error_report("Failed to read msg header."
238                 " Size %d exceeds the maximum %zu.", msg->hdr.size,
239                 VHOST_USER_PAYLOAD_SIZE);
240         goto fail;
241     }
242 
243     if (msg->hdr.size) {
244         p += VHOST_USER_HDR_SIZE;
245         size = msg->hdr.size;
246         r = qemu_chr_fe_read_all(chr, p, size);
247         if (r != size) {
248             error_report("Failed to read msg payload."
249                          " Read %d instead of %d.", r, msg->hdr.size);
250             goto fail;
251         }
252     }
253 
254     return 0;
255 
256 fail:
257     return -1;
258 }
259 
260 static int process_message_reply(struct vhost_dev *dev,
261                                  const VhostUserMsg *msg)
262 {
263     VhostUserMsg msg_reply;
264 
265     if ((msg->hdr.flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
266         return 0;
267     }
268 
269     if (vhost_user_read(dev, &msg_reply) < 0) {
270         return -1;
271     }
272 
273     if (msg_reply.hdr.request != msg->hdr.request) {
274         error_report("Received unexpected msg type."
275                      "Expected %d received %d",
276                      msg->hdr.request, msg_reply.hdr.request);
277         return -1;
278     }
279 
280     return msg_reply.payload.u64 ? -1 : 0;
281 }
282 
283 static bool vhost_user_one_time_request(VhostUserRequest request)
284 {
285     switch (request) {
286     case VHOST_USER_SET_OWNER:
287     case VHOST_USER_RESET_OWNER:
288     case VHOST_USER_SET_MEM_TABLE:
289     case VHOST_USER_GET_QUEUE_NUM:
290     case VHOST_USER_NET_SET_MTU:
291         return true;
292     default:
293         return false;
294     }
295 }
296 
297 /* most non-init callers ignore the error */
298 static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
299                             int *fds, int fd_num)
300 {
301     struct vhost_user *u = dev->opaque;
302     CharBackend *chr = u->user->chr;
303     int ret, size = VHOST_USER_HDR_SIZE + msg->hdr.size;
304 
305     /*
306      * For non-vring specific requests, like VHOST_USER_SET_MEM_TABLE,
307      * we just need send it once in the first time. For later such
308      * request, we just ignore it.
309      */
310     if (vhost_user_one_time_request(msg->hdr.request) && dev->vq_index != 0) {
311         msg->hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
312         return 0;
313     }
314 
315     if (qemu_chr_fe_set_msgfds(chr, fds, fd_num) < 0) {
316         error_report("Failed to set msg fds.");
317         return -1;
318     }
319 
320     ret = qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size);
321     if (ret != size) {
322         error_report("Failed to write msg."
323                      " Wrote %d instead of %d.", ret, size);
324         return -1;
325     }
326 
327     return 0;
328 }
329 
330 static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
331                                    struct vhost_log *log)
332 {
333     int fds[VHOST_MEMORY_MAX_NREGIONS];
334     size_t fd_num = 0;
335     bool shmfd = virtio_has_feature(dev->protocol_features,
336                                     VHOST_USER_PROTOCOL_F_LOG_SHMFD);
337     VhostUserMsg msg = {
338         .hdr.request = VHOST_USER_SET_LOG_BASE,
339         .hdr.flags = VHOST_USER_VERSION,
340         .payload.log.mmap_size = log->size * sizeof(*(log->log)),
341         .payload.log.mmap_offset = 0,
342         .hdr.size = sizeof(msg.payload.log),
343     };
344 
345     if (shmfd && log->fd != -1) {
346         fds[fd_num++] = log->fd;
347     }
348 
349     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
350         return -1;
351     }
352 
353     if (shmfd) {
354         msg.hdr.size = 0;
355         if (vhost_user_read(dev, &msg) < 0) {
356             return -1;
357         }
358 
359         if (msg.hdr.request != VHOST_USER_SET_LOG_BASE) {
360             error_report("Received unexpected msg type. "
361                          "Expected %d received %d",
362                          VHOST_USER_SET_LOG_BASE, msg.hdr.request);
363             return -1;
364         }
365     }
366 
367     return 0;
368 }
369 
370 static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
371                                              struct vhost_memory *mem)
372 {
373     struct vhost_user *u = dev->opaque;
374     int fds[VHOST_MEMORY_MAX_NREGIONS];
375     int i, fd;
376     size_t fd_num = 0;
377     VhostUserMsg msg_reply;
378     int region_i, msg_i;
379 
380     VhostUserMsg msg = {
381         .hdr.request = VHOST_USER_SET_MEM_TABLE,
382         .hdr.flags = VHOST_USER_VERSION,
383     };
384 
385     if (u->region_rb_len < dev->mem->nregions) {
386         u->region_rb = g_renew(RAMBlock*, u->region_rb, dev->mem->nregions);
387         u->region_rb_offset = g_renew(ram_addr_t, u->region_rb_offset,
388                                       dev->mem->nregions);
389         memset(&(u->region_rb[u->region_rb_len]), '\0',
390                sizeof(RAMBlock *) * (dev->mem->nregions - u->region_rb_len));
391         memset(&(u->region_rb_offset[u->region_rb_len]), '\0',
392                sizeof(ram_addr_t) * (dev->mem->nregions - u->region_rb_len));
393         u->region_rb_len = dev->mem->nregions;
394     }
395 
396     for (i = 0; i < dev->mem->nregions; ++i) {
397         struct vhost_memory_region *reg = dev->mem->regions + i;
398         ram_addr_t offset;
399         MemoryRegion *mr;
400 
401         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
402         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
403                                      &offset);
404         fd = memory_region_get_fd(mr);
405         if (fd > 0) {
406             trace_vhost_user_set_mem_table_withfd(fd_num, mr->name,
407                                                   reg->memory_size,
408                                                   reg->guest_phys_addr,
409                                                   reg->userspace_addr, offset);
410             u->region_rb_offset[i] = offset;
411             u->region_rb[i] = mr->ram_block;
412             msg.payload.memory.regions[fd_num].userspace_addr =
413                 reg->userspace_addr;
414             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
415             msg.payload.memory.regions[fd_num].guest_phys_addr =
416                 reg->guest_phys_addr;
417             msg.payload.memory.regions[fd_num].mmap_offset = offset;
418             assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
419             fds[fd_num++] = fd;
420         } else {
421             u->region_rb_offset[i] = 0;
422             u->region_rb[i] = NULL;
423         }
424     }
425 
426     msg.payload.memory.nregions = fd_num;
427 
428     if (!fd_num) {
429         error_report("Failed initializing vhost-user memory map, "
430                      "consider using -object memory-backend-file share=on");
431         return -1;
432     }
433 
434     msg.hdr.size = sizeof(msg.payload.memory.nregions);
435     msg.hdr.size += sizeof(msg.payload.memory.padding);
436     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
437 
438     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
439         return -1;
440     }
441 
442     if (vhost_user_read(dev, &msg_reply) < 0) {
443         return -1;
444     }
445 
446     if (msg_reply.hdr.request != VHOST_USER_SET_MEM_TABLE) {
447         error_report("%s: Received unexpected msg type."
448                      "Expected %d received %d", __func__,
449                      VHOST_USER_SET_MEM_TABLE, msg_reply.hdr.request);
450         return -1;
451     }
452     /* We're using the same structure, just reusing one of the
453      * fields, so it should be the same size.
454      */
455     if (msg_reply.hdr.size != msg.hdr.size) {
456         error_report("%s: Unexpected size for postcopy reply "
457                      "%d vs %d", __func__, msg_reply.hdr.size, msg.hdr.size);
458         return -1;
459     }
460 
461     memset(u->postcopy_client_bases, 0,
462            sizeof(uint64_t) * VHOST_MEMORY_MAX_NREGIONS);
463 
464     /* They're in the same order as the regions that were sent
465      * but some of the regions were skipped (above) if they
466      * didn't have fd's
467     */
468     for (msg_i = 0, region_i = 0;
469          region_i < dev->mem->nregions;
470         region_i++) {
471         if (msg_i < fd_num &&
472             msg_reply.payload.memory.regions[msg_i].guest_phys_addr ==
473             dev->mem->regions[region_i].guest_phys_addr) {
474             u->postcopy_client_bases[region_i] =
475                 msg_reply.payload.memory.regions[msg_i].userspace_addr;
476             trace_vhost_user_set_mem_table_postcopy(
477                 msg_reply.payload.memory.regions[msg_i].userspace_addr,
478                 msg.payload.memory.regions[msg_i].userspace_addr,
479                 msg_i, region_i);
480             msg_i++;
481         }
482     }
483     if (msg_i != fd_num) {
484         error_report("%s: postcopy reply not fully consumed "
485                      "%d vs %zd",
486                      __func__, msg_i, fd_num);
487         return -1;
488     }
489     /* Now we've registered this with the postcopy code, we ack to the client,
490      * because now we're in the position to be able to deal with any faults
491      * it generates.
492      */
493     /* TODO: Use this for failure cases as well with a bad value */
494     msg.hdr.size = sizeof(msg.payload.u64);
495     msg.payload.u64 = 0; /* OK */
496     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
497         return -1;
498     }
499 
500     return 0;
501 }
502 
503 static int vhost_user_set_mem_table(struct vhost_dev *dev,
504                                     struct vhost_memory *mem)
505 {
506     struct vhost_user *u = dev->opaque;
507     int fds[VHOST_MEMORY_MAX_NREGIONS];
508     int i, fd;
509     size_t fd_num = 0;
510     bool do_postcopy = u->postcopy_listen && u->postcopy_fd.handler;
511     bool reply_supported = virtio_has_feature(dev->protocol_features,
512                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
513 
514     if (do_postcopy) {
515         /* Postcopy has enough differences that it's best done in it's own
516          * version
517          */
518         return vhost_user_set_mem_table_postcopy(dev, mem);
519     }
520 
521     VhostUserMsg msg = {
522         .hdr.request = VHOST_USER_SET_MEM_TABLE,
523         .hdr.flags = VHOST_USER_VERSION,
524     };
525 
526     if (reply_supported) {
527         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
528     }
529 
530     for (i = 0; i < dev->mem->nregions; ++i) {
531         struct vhost_memory_region *reg = dev->mem->regions + i;
532         ram_addr_t offset;
533         MemoryRegion *mr;
534 
535         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
536         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
537                                      &offset);
538         fd = memory_region_get_fd(mr);
539         if (fd > 0) {
540             if (fd_num == VHOST_MEMORY_MAX_NREGIONS) {
541                 error_report("Failed preparing vhost-user memory table msg");
542                 return -1;
543             }
544             msg.payload.memory.regions[fd_num].userspace_addr =
545                 reg->userspace_addr;
546             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
547             msg.payload.memory.regions[fd_num].guest_phys_addr =
548                 reg->guest_phys_addr;
549             msg.payload.memory.regions[fd_num].mmap_offset = offset;
550             fds[fd_num++] = fd;
551         }
552     }
553 
554     msg.payload.memory.nregions = fd_num;
555 
556     if (!fd_num) {
557         error_report("Failed initializing vhost-user memory map, "
558                      "consider using -object memory-backend-file share=on");
559         return -1;
560     }
561 
562     msg.hdr.size = sizeof(msg.payload.memory.nregions);
563     msg.hdr.size += sizeof(msg.payload.memory.padding);
564     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
565 
566     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
567         return -1;
568     }
569 
570     if (reply_supported) {
571         return process_message_reply(dev, &msg);
572     }
573 
574     return 0;
575 }
576 
577 static int vhost_user_set_vring_addr(struct vhost_dev *dev,
578                                      struct vhost_vring_addr *addr)
579 {
580     VhostUserMsg msg = {
581         .hdr.request = VHOST_USER_SET_VRING_ADDR,
582         .hdr.flags = VHOST_USER_VERSION,
583         .payload.addr = *addr,
584         .hdr.size = sizeof(msg.payload.addr),
585     };
586 
587     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
588         return -1;
589     }
590 
591     return 0;
592 }
593 
594 static int vhost_user_set_vring_endian(struct vhost_dev *dev,
595                                        struct vhost_vring_state *ring)
596 {
597     bool cross_endian = virtio_has_feature(dev->protocol_features,
598                                            VHOST_USER_PROTOCOL_F_CROSS_ENDIAN);
599     VhostUserMsg msg = {
600         .hdr.request = VHOST_USER_SET_VRING_ENDIAN,
601         .hdr.flags = VHOST_USER_VERSION,
602         .payload.state = *ring,
603         .hdr.size = sizeof(msg.payload.state),
604     };
605 
606     if (!cross_endian) {
607         error_report("vhost-user trying to send unhandled ioctl");
608         return -1;
609     }
610 
611     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
612         return -1;
613     }
614 
615     return 0;
616 }
617 
618 static int vhost_set_vring(struct vhost_dev *dev,
619                            unsigned long int request,
620                            struct vhost_vring_state *ring)
621 {
622     VhostUserMsg msg = {
623         .hdr.request = request,
624         .hdr.flags = VHOST_USER_VERSION,
625         .payload.state = *ring,
626         .hdr.size = sizeof(msg.payload.state),
627     };
628 
629     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
630         return -1;
631     }
632 
633     return 0;
634 }
635 
636 static int vhost_user_set_vring_num(struct vhost_dev *dev,
637                                     struct vhost_vring_state *ring)
638 {
639     return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
640 }
641 
642 static void vhost_user_host_notifier_restore(struct vhost_dev *dev,
643                                              int queue_idx)
644 {
645     struct vhost_user *u = dev->opaque;
646     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
647     VirtIODevice *vdev = dev->vdev;
648 
649     if (n->addr && !n->set) {
650         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true);
651         n->set = true;
652     }
653 }
654 
655 static void vhost_user_host_notifier_remove(struct vhost_dev *dev,
656                                             int queue_idx)
657 {
658     struct vhost_user *u = dev->opaque;
659     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
660     VirtIODevice *vdev = dev->vdev;
661 
662     if (n->addr && n->set) {
663         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
664         n->set = false;
665     }
666 }
667 
668 static int vhost_user_set_vring_base(struct vhost_dev *dev,
669                                      struct vhost_vring_state *ring)
670 {
671     vhost_user_host_notifier_restore(dev, ring->index);
672 
673     return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
674 }
675 
676 static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
677 {
678     int i;
679 
680     if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
681         return -1;
682     }
683 
684     for (i = 0; i < dev->nvqs; ++i) {
685         struct vhost_vring_state state = {
686             .index = dev->vq_index + i,
687             .num   = enable,
688         };
689 
690         vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
691     }
692 
693     return 0;
694 }
695 
696 static int vhost_user_get_vring_base(struct vhost_dev *dev,
697                                      struct vhost_vring_state *ring)
698 {
699     VhostUserMsg msg = {
700         .hdr.request = VHOST_USER_GET_VRING_BASE,
701         .hdr.flags = VHOST_USER_VERSION,
702         .payload.state = *ring,
703         .hdr.size = sizeof(msg.payload.state),
704     };
705 
706     vhost_user_host_notifier_remove(dev, ring->index);
707 
708     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
709         return -1;
710     }
711 
712     if (vhost_user_read(dev, &msg) < 0) {
713         return -1;
714     }
715 
716     if (msg.hdr.request != VHOST_USER_GET_VRING_BASE) {
717         error_report("Received unexpected msg type. Expected %d received %d",
718                      VHOST_USER_GET_VRING_BASE, msg.hdr.request);
719         return -1;
720     }
721 
722     if (msg.hdr.size != sizeof(msg.payload.state)) {
723         error_report("Received bad msg size.");
724         return -1;
725     }
726 
727     *ring = msg.payload.state;
728 
729     return 0;
730 }
731 
732 static int vhost_set_vring_file(struct vhost_dev *dev,
733                                 VhostUserRequest request,
734                                 struct vhost_vring_file *file)
735 {
736     int fds[VHOST_MEMORY_MAX_NREGIONS];
737     size_t fd_num = 0;
738     VhostUserMsg msg = {
739         .hdr.request = request,
740         .hdr.flags = VHOST_USER_VERSION,
741         .payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
742         .hdr.size = sizeof(msg.payload.u64),
743     };
744 
745     if (ioeventfd_enabled() && file->fd > 0) {
746         fds[fd_num++] = file->fd;
747     } else {
748         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
749     }
750 
751     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
752         return -1;
753     }
754 
755     return 0;
756 }
757 
758 static int vhost_user_set_vring_kick(struct vhost_dev *dev,
759                                      struct vhost_vring_file *file)
760 {
761     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
762 }
763 
764 static int vhost_user_set_vring_call(struct vhost_dev *dev,
765                                      struct vhost_vring_file *file)
766 {
767     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
768 }
769 
770 static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64)
771 {
772     VhostUserMsg msg = {
773         .hdr.request = request,
774         .hdr.flags = VHOST_USER_VERSION,
775         .payload.u64 = u64,
776         .hdr.size = sizeof(msg.payload.u64),
777     };
778 
779     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
780         return -1;
781     }
782 
783     return 0;
784 }
785 
786 static int vhost_user_set_features(struct vhost_dev *dev,
787                                    uint64_t features)
788 {
789     return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features);
790 }
791 
792 static int vhost_user_set_protocol_features(struct vhost_dev *dev,
793                                             uint64_t features)
794 {
795     return vhost_user_set_u64(dev, VHOST_USER_SET_PROTOCOL_FEATURES, features);
796 }
797 
798 static int vhost_user_get_u64(struct vhost_dev *dev, int request, uint64_t *u64)
799 {
800     VhostUserMsg msg = {
801         .hdr.request = request,
802         .hdr.flags = VHOST_USER_VERSION,
803     };
804 
805     if (vhost_user_one_time_request(request) && dev->vq_index != 0) {
806         return 0;
807     }
808 
809     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
810         return -1;
811     }
812 
813     if (vhost_user_read(dev, &msg) < 0) {
814         return -1;
815     }
816 
817     if (msg.hdr.request != request) {
818         error_report("Received unexpected msg type. Expected %d received %d",
819                      request, msg.hdr.request);
820         return -1;
821     }
822 
823     if (msg.hdr.size != sizeof(msg.payload.u64)) {
824         error_report("Received bad msg size.");
825         return -1;
826     }
827 
828     *u64 = msg.payload.u64;
829 
830     return 0;
831 }
832 
833 static int vhost_user_get_features(struct vhost_dev *dev, uint64_t *features)
834 {
835     return vhost_user_get_u64(dev, VHOST_USER_GET_FEATURES, features);
836 }
837 
838 static int vhost_user_set_owner(struct vhost_dev *dev)
839 {
840     VhostUserMsg msg = {
841         .hdr.request = VHOST_USER_SET_OWNER,
842         .hdr.flags = VHOST_USER_VERSION,
843     };
844 
845     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
846         return -1;
847     }
848 
849     return 0;
850 }
851 
852 static int vhost_user_reset_device(struct vhost_dev *dev)
853 {
854     VhostUserMsg msg = {
855         .hdr.request = VHOST_USER_RESET_OWNER,
856         .hdr.flags = VHOST_USER_VERSION,
857     };
858 
859     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
860         return -1;
861     }
862 
863     return 0;
864 }
865 
866 static int vhost_user_slave_handle_config_change(struct vhost_dev *dev)
867 {
868     int ret = -1;
869 
870     if (!dev->config_ops) {
871         return -1;
872     }
873 
874     if (dev->config_ops->vhost_dev_config_notifier) {
875         ret = dev->config_ops->vhost_dev_config_notifier(dev);
876     }
877 
878     return ret;
879 }
880 
881 static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev,
882                                                        VhostUserVringArea *area,
883                                                        int fd)
884 {
885     int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK;
886     size_t page_size = qemu_real_host_page_size;
887     struct vhost_user *u = dev->opaque;
888     VhostUserState *user = u->user;
889     VirtIODevice *vdev = dev->vdev;
890     VhostUserHostNotifier *n;
891     void *addr;
892     char *name;
893 
894     if (!virtio_has_feature(dev->protocol_features,
895                             VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) ||
896         vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) {
897         return -1;
898     }
899 
900     n = &user->notifier[queue_idx];
901 
902     if (n->addr) {
903         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
904         object_unparent(OBJECT(&n->mr));
905         munmap(n->addr, page_size);
906         n->addr = NULL;
907     }
908 
909     if (area->u64 & VHOST_USER_VRING_NOFD_MASK) {
910         return 0;
911     }
912 
913     /* Sanity check. */
914     if (area->size != page_size) {
915         return -1;
916     }
917 
918     addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
919                 fd, area->offset);
920     if (addr == MAP_FAILED) {
921         return -1;
922     }
923 
924     name = g_strdup_printf("vhost-user/host-notifier@%p mmaps[%d]",
925                            user, queue_idx);
926     memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name,
927                                       page_size, addr);
928     g_free(name);
929 
930     if (virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true)) {
931         munmap(addr, page_size);
932         return -1;
933     }
934 
935     n->addr = addr;
936     n->set = true;
937 
938     return 0;
939 }
940 
941 static void slave_read(void *opaque)
942 {
943     struct vhost_dev *dev = opaque;
944     struct vhost_user *u = dev->opaque;
945     VhostUserHeader hdr = { 0, };
946     VhostUserPayload payload = { 0, };
947     int size, ret = 0;
948     struct iovec iov;
949     struct msghdr msgh;
950     int fd[VHOST_USER_SLAVE_MAX_FDS];
951     char control[CMSG_SPACE(sizeof(fd))];
952     struct cmsghdr *cmsg;
953     int i, fdsize = 0;
954 
955     memset(&msgh, 0, sizeof(msgh));
956     msgh.msg_iov = &iov;
957     msgh.msg_iovlen = 1;
958     msgh.msg_control = control;
959     msgh.msg_controllen = sizeof(control);
960 
961     memset(fd, -1, sizeof(fd));
962 
963     /* Read header */
964     iov.iov_base = &hdr;
965     iov.iov_len = VHOST_USER_HDR_SIZE;
966 
967     size = recvmsg(u->slave_fd, &msgh, 0);
968     if (size != VHOST_USER_HDR_SIZE) {
969         error_report("Failed to read from slave.");
970         goto err;
971     }
972 
973     if (msgh.msg_flags & MSG_CTRUNC) {
974         error_report("Truncated message.");
975         goto err;
976     }
977 
978     for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;
979          cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
980             if (cmsg->cmsg_level == SOL_SOCKET &&
981                 cmsg->cmsg_type == SCM_RIGHTS) {
982                     fdsize = cmsg->cmsg_len - CMSG_LEN(0);
983                     memcpy(fd, CMSG_DATA(cmsg), fdsize);
984                     break;
985             }
986     }
987 
988     if (hdr.size > VHOST_USER_PAYLOAD_SIZE) {
989         error_report("Failed to read msg header."
990                 " Size %d exceeds the maximum %zu.", hdr.size,
991                 VHOST_USER_PAYLOAD_SIZE);
992         goto err;
993     }
994 
995     /* Read payload */
996     size = read(u->slave_fd, &payload, hdr.size);
997     if (size != hdr.size) {
998         error_report("Failed to read payload from slave.");
999         goto err;
1000     }
1001 
1002     switch (hdr.request) {
1003     case VHOST_USER_SLAVE_IOTLB_MSG:
1004         ret = vhost_backend_handle_iotlb_msg(dev, &payload.iotlb);
1005         break;
1006     case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG :
1007         ret = vhost_user_slave_handle_config_change(dev);
1008         break;
1009     case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
1010         ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area,
1011                                                           fd[0]);
1012         break;
1013     default:
1014         error_report("Received unexpected msg type.");
1015         ret = -EINVAL;
1016     }
1017 
1018     /* Close the remaining file descriptors. */
1019     for (i = 0; i < fdsize; i++) {
1020         if (fd[i] != -1) {
1021             close(fd[i]);
1022         }
1023     }
1024 
1025     /*
1026      * REPLY_ACK feature handling. Other reply types has to be managed
1027      * directly in their request handlers.
1028      */
1029     if (hdr.flags & VHOST_USER_NEED_REPLY_MASK) {
1030         struct iovec iovec[2];
1031 
1032 
1033         hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
1034         hdr.flags |= VHOST_USER_REPLY_MASK;
1035 
1036         payload.u64 = !!ret;
1037         hdr.size = sizeof(payload.u64);
1038 
1039         iovec[0].iov_base = &hdr;
1040         iovec[0].iov_len = VHOST_USER_HDR_SIZE;
1041         iovec[1].iov_base = &payload;
1042         iovec[1].iov_len = hdr.size;
1043 
1044         size = writev(u->slave_fd, iovec, ARRAY_SIZE(iovec));
1045         if (size != VHOST_USER_HDR_SIZE + hdr.size) {
1046             error_report("Failed to send msg reply to slave.");
1047             goto err;
1048         }
1049     }
1050 
1051     return;
1052 
1053 err:
1054     qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1055     close(u->slave_fd);
1056     u->slave_fd = -1;
1057     for (i = 0; i < fdsize; i++) {
1058         if (fd[i] != -1) {
1059             close(fd[i]);
1060         }
1061     }
1062     return;
1063 }
1064 
1065 static int vhost_setup_slave_channel(struct vhost_dev *dev)
1066 {
1067     VhostUserMsg msg = {
1068         .hdr.request = VHOST_USER_SET_SLAVE_REQ_FD,
1069         .hdr.flags = VHOST_USER_VERSION,
1070     };
1071     struct vhost_user *u = dev->opaque;
1072     int sv[2], ret = 0;
1073     bool reply_supported = virtio_has_feature(dev->protocol_features,
1074                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1075 
1076     if (!virtio_has_feature(dev->protocol_features,
1077                             VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
1078         return 0;
1079     }
1080 
1081     if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
1082         error_report("socketpair() failed");
1083         return -1;
1084     }
1085 
1086     u->slave_fd = sv[0];
1087     qemu_set_fd_handler(u->slave_fd, slave_read, NULL, dev);
1088 
1089     if (reply_supported) {
1090         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1091     }
1092 
1093     ret = vhost_user_write(dev, &msg, &sv[1], 1);
1094     if (ret) {
1095         goto out;
1096     }
1097 
1098     if (reply_supported) {
1099         ret = process_message_reply(dev, &msg);
1100     }
1101 
1102 out:
1103     close(sv[1]);
1104     if (ret) {
1105         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1106         close(u->slave_fd);
1107         u->slave_fd = -1;
1108     }
1109 
1110     return ret;
1111 }
1112 
1113 /*
1114  * Called back from the postcopy fault thread when a fault is received on our
1115  * ufd.
1116  * TODO: This is Linux specific
1117  */
1118 static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
1119                                              void *ufd)
1120 {
1121     struct vhost_dev *dev = pcfd->data;
1122     struct vhost_user *u = dev->opaque;
1123     struct uffd_msg *msg = ufd;
1124     uint64_t faultaddr = msg->arg.pagefault.address;
1125     RAMBlock *rb = NULL;
1126     uint64_t rb_offset;
1127     int i;
1128 
1129     trace_vhost_user_postcopy_fault_handler(pcfd->idstr, faultaddr,
1130                                             dev->mem->nregions);
1131     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1132         trace_vhost_user_postcopy_fault_handler_loop(i,
1133                 u->postcopy_client_bases[i], dev->mem->regions[i].memory_size);
1134         if (faultaddr >= u->postcopy_client_bases[i]) {
1135             /* Ofset of the fault address in the vhost region */
1136             uint64_t region_offset = faultaddr - u->postcopy_client_bases[i];
1137             if (region_offset < dev->mem->regions[i].memory_size) {
1138                 rb_offset = region_offset + u->region_rb_offset[i];
1139                 trace_vhost_user_postcopy_fault_handler_found(i,
1140                         region_offset, rb_offset);
1141                 rb = u->region_rb[i];
1142                 return postcopy_request_shared_page(pcfd, rb, faultaddr,
1143                                                     rb_offset);
1144             }
1145         }
1146     }
1147     error_report("%s: Failed to find region for fault %" PRIx64,
1148                  __func__, faultaddr);
1149     return -1;
1150 }
1151 
1152 static int vhost_user_postcopy_waker(struct PostCopyFD *pcfd, RAMBlock *rb,
1153                                      uint64_t offset)
1154 {
1155     struct vhost_dev *dev = pcfd->data;
1156     struct vhost_user *u = dev->opaque;
1157     int i;
1158 
1159     trace_vhost_user_postcopy_waker(qemu_ram_get_idstr(rb), offset);
1160 
1161     if (!u) {
1162         return 0;
1163     }
1164     /* Translate the offset into an address in the clients address space */
1165     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1166         if (u->region_rb[i] == rb &&
1167             offset >= u->region_rb_offset[i] &&
1168             offset < (u->region_rb_offset[i] +
1169                       dev->mem->regions[i].memory_size)) {
1170             uint64_t client_addr = (offset - u->region_rb_offset[i]) +
1171                                    u->postcopy_client_bases[i];
1172             trace_vhost_user_postcopy_waker_found(client_addr);
1173             return postcopy_wake_shared(pcfd, client_addr, rb);
1174         }
1175     }
1176 
1177     trace_vhost_user_postcopy_waker_nomatch(qemu_ram_get_idstr(rb), offset);
1178     return 0;
1179 }
1180 
1181 /*
1182  * Called at the start of an inbound postcopy on reception of the
1183  * 'advise' command.
1184  */
1185 static int vhost_user_postcopy_advise(struct vhost_dev *dev, Error **errp)
1186 {
1187     struct vhost_user *u = dev->opaque;
1188     CharBackend *chr = u->user->chr;
1189     int ufd;
1190     VhostUserMsg msg = {
1191         .hdr.request = VHOST_USER_POSTCOPY_ADVISE,
1192         .hdr.flags = VHOST_USER_VERSION,
1193     };
1194 
1195     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1196         error_setg(errp, "Failed to send postcopy_advise to vhost");
1197         return -1;
1198     }
1199 
1200     if (vhost_user_read(dev, &msg) < 0) {
1201         error_setg(errp, "Failed to get postcopy_advise reply from vhost");
1202         return -1;
1203     }
1204 
1205     if (msg.hdr.request != VHOST_USER_POSTCOPY_ADVISE) {
1206         error_setg(errp, "Unexpected msg type. Expected %d received %d",
1207                      VHOST_USER_POSTCOPY_ADVISE, msg.hdr.request);
1208         return -1;
1209     }
1210 
1211     if (msg.hdr.size) {
1212         error_setg(errp, "Received bad msg size.");
1213         return -1;
1214     }
1215     ufd = qemu_chr_fe_get_msgfd(chr);
1216     if (ufd < 0) {
1217         error_setg(errp, "%s: Failed to get ufd", __func__);
1218         return -1;
1219     }
1220     qemu_set_nonblock(ufd);
1221 
1222     /* register ufd with userfault thread */
1223     u->postcopy_fd.fd = ufd;
1224     u->postcopy_fd.data = dev;
1225     u->postcopy_fd.handler = vhost_user_postcopy_fault_handler;
1226     u->postcopy_fd.waker = vhost_user_postcopy_waker;
1227     u->postcopy_fd.idstr = "vhost-user"; /* Need to find unique name */
1228     postcopy_register_shared_ufd(&u->postcopy_fd);
1229     return 0;
1230 }
1231 
1232 /*
1233  * Called at the switch to postcopy on reception of the 'listen' command.
1234  */
1235 static int vhost_user_postcopy_listen(struct vhost_dev *dev, Error **errp)
1236 {
1237     struct vhost_user *u = dev->opaque;
1238     int ret;
1239     VhostUserMsg msg = {
1240         .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
1241         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1242     };
1243     u->postcopy_listen = true;
1244     trace_vhost_user_postcopy_listen();
1245     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1246         error_setg(errp, "Failed to send postcopy_listen to vhost");
1247         return -1;
1248     }
1249 
1250     ret = process_message_reply(dev, &msg);
1251     if (ret) {
1252         error_setg(errp, "Failed to receive reply to postcopy_listen");
1253         return ret;
1254     }
1255 
1256     return 0;
1257 }
1258 
1259 /*
1260  * Called at the end of postcopy
1261  */
1262 static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
1263 {
1264     VhostUserMsg msg = {
1265         .hdr.request = VHOST_USER_POSTCOPY_END,
1266         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1267     };
1268     int ret;
1269     struct vhost_user *u = dev->opaque;
1270 
1271     trace_vhost_user_postcopy_end_entry();
1272     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1273         error_setg(errp, "Failed to send postcopy_end to vhost");
1274         return -1;
1275     }
1276 
1277     ret = process_message_reply(dev, &msg);
1278     if (ret) {
1279         error_setg(errp, "Failed to receive reply to postcopy_end");
1280         return ret;
1281     }
1282     postcopy_unregister_shared_ufd(&u->postcopy_fd);
1283     close(u->postcopy_fd.fd);
1284     u->postcopy_fd.handler = NULL;
1285 
1286     trace_vhost_user_postcopy_end_exit();
1287 
1288     return 0;
1289 }
1290 
1291 static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
1292                                         void *opaque)
1293 {
1294     struct PostcopyNotifyData *pnd = opaque;
1295     struct vhost_user *u = container_of(notifier, struct vhost_user,
1296                                          postcopy_notifier);
1297     struct vhost_dev *dev = u->dev;
1298 
1299     switch (pnd->reason) {
1300     case POSTCOPY_NOTIFY_PROBE:
1301         if (!virtio_has_feature(dev->protocol_features,
1302                                 VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
1303             /* TODO: Get the device name into this error somehow */
1304             error_setg(pnd->errp,
1305                        "vhost-user backend not capable of postcopy");
1306             return -ENOENT;
1307         }
1308         break;
1309 
1310     case POSTCOPY_NOTIFY_INBOUND_ADVISE:
1311         return vhost_user_postcopy_advise(dev, pnd->errp);
1312 
1313     case POSTCOPY_NOTIFY_INBOUND_LISTEN:
1314         return vhost_user_postcopy_listen(dev, pnd->errp);
1315 
1316     case POSTCOPY_NOTIFY_INBOUND_END:
1317         return vhost_user_postcopy_end(dev, pnd->errp);
1318 
1319     default:
1320         /* We ignore notifications we don't know */
1321         break;
1322     }
1323 
1324     return 0;
1325 }
1326 
1327 static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque)
1328 {
1329     uint64_t features, protocol_features;
1330     struct vhost_user *u;
1331     int err;
1332 
1333     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1334 
1335     u = g_new0(struct vhost_user, 1);
1336     u->user = opaque;
1337     u->slave_fd = -1;
1338     u->dev = dev;
1339     dev->opaque = u;
1340 
1341     err = vhost_user_get_features(dev, &features);
1342     if (err < 0) {
1343         return err;
1344     }
1345 
1346     if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
1347         dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
1348 
1349         err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
1350                                  &protocol_features);
1351         if (err < 0) {
1352             return err;
1353         }
1354 
1355         dev->protocol_features =
1356             protocol_features & VHOST_USER_PROTOCOL_FEATURE_MASK;
1357 
1358         if (!dev->config_ops || !dev->config_ops->vhost_dev_config_notifier) {
1359             /* Don't acknowledge CONFIG feature if device doesn't support it */
1360             dev->protocol_features &= ~(1ULL << VHOST_USER_PROTOCOL_F_CONFIG);
1361         } else if (!(protocol_features &
1362                     (1ULL << VHOST_USER_PROTOCOL_F_CONFIG))) {
1363             error_report("Device expects VHOST_USER_PROTOCOL_F_CONFIG "
1364                     "but backend does not support it.");
1365             return -1;
1366         }
1367 
1368         err = vhost_user_set_protocol_features(dev, dev->protocol_features);
1369         if (err < 0) {
1370             return err;
1371         }
1372 
1373         /* query the max queues we support if backend supports Multiple Queue */
1374         if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
1375             err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
1376                                      &dev->max_queues);
1377             if (err < 0) {
1378                 return err;
1379             }
1380         }
1381 
1382         if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) &&
1383                 !(virtio_has_feature(dev->protocol_features,
1384                     VHOST_USER_PROTOCOL_F_SLAVE_REQ) &&
1385                  virtio_has_feature(dev->protocol_features,
1386                     VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1387             error_report("IOMMU support requires reply-ack and "
1388                          "slave-req protocol features.");
1389             return -1;
1390         }
1391     }
1392 
1393     if (dev->migration_blocker == NULL &&
1394         !virtio_has_feature(dev->protocol_features,
1395                             VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
1396         error_setg(&dev->migration_blocker,
1397                    "Migration disabled: vhost-user backend lacks "
1398                    "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
1399     }
1400 
1401     err = vhost_setup_slave_channel(dev);
1402     if (err < 0) {
1403         return err;
1404     }
1405 
1406     u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
1407     postcopy_add_notifier(&u->postcopy_notifier);
1408 
1409     return 0;
1410 }
1411 
1412 static int vhost_user_backend_cleanup(struct vhost_dev *dev)
1413 {
1414     struct vhost_user *u;
1415 
1416     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1417 
1418     u = dev->opaque;
1419     if (u->postcopy_notifier.notify) {
1420         postcopy_remove_notifier(&u->postcopy_notifier);
1421         u->postcopy_notifier.notify = NULL;
1422     }
1423     u->postcopy_listen = false;
1424     if (u->postcopy_fd.handler) {
1425         postcopy_unregister_shared_ufd(&u->postcopy_fd);
1426         close(u->postcopy_fd.fd);
1427         u->postcopy_fd.handler = NULL;
1428     }
1429     if (u->slave_fd >= 0) {
1430         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1431         close(u->slave_fd);
1432         u->slave_fd = -1;
1433     }
1434     g_free(u->region_rb);
1435     u->region_rb = NULL;
1436     g_free(u->region_rb_offset);
1437     u->region_rb_offset = NULL;
1438     u->region_rb_len = 0;
1439     g_free(u);
1440     dev->opaque = 0;
1441 
1442     return 0;
1443 }
1444 
1445 static int vhost_user_get_vq_index(struct vhost_dev *dev, int idx)
1446 {
1447     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
1448 
1449     return idx;
1450 }
1451 
1452 static int vhost_user_memslots_limit(struct vhost_dev *dev)
1453 {
1454     return VHOST_MEMORY_MAX_NREGIONS;
1455 }
1456 
1457 static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
1458 {
1459     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1460 
1461     return virtio_has_feature(dev->protocol_features,
1462                               VHOST_USER_PROTOCOL_F_LOG_SHMFD);
1463 }
1464 
1465 static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
1466 {
1467     VhostUserMsg msg = { };
1468 
1469     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1470 
1471     /* If guest supports GUEST_ANNOUNCE do nothing */
1472     if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {
1473         return 0;
1474     }
1475 
1476     /* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
1477     if (virtio_has_feature(dev->protocol_features,
1478                            VHOST_USER_PROTOCOL_F_RARP)) {
1479         msg.hdr.request = VHOST_USER_SEND_RARP;
1480         msg.hdr.flags = VHOST_USER_VERSION;
1481         memcpy((char *)&msg.payload.u64, mac_addr, 6);
1482         msg.hdr.size = sizeof(msg.payload.u64);
1483 
1484         return vhost_user_write(dev, &msg, NULL, 0);
1485     }
1486     return -1;
1487 }
1488 
1489 static bool vhost_user_can_merge(struct vhost_dev *dev,
1490                                  uint64_t start1, uint64_t size1,
1491                                  uint64_t start2, uint64_t size2)
1492 {
1493     ram_addr_t offset;
1494     int mfd, rfd;
1495     MemoryRegion *mr;
1496 
1497     mr = memory_region_from_host((void *)(uintptr_t)start1, &offset);
1498     mfd = memory_region_get_fd(mr);
1499 
1500     mr = memory_region_from_host((void *)(uintptr_t)start2, &offset);
1501     rfd = memory_region_get_fd(mr);
1502 
1503     return mfd == rfd;
1504 }
1505 
1506 static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu)
1507 {
1508     VhostUserMsg msg;
1509     bool reply_supported = virtio_has_feature(dev->protocol_features,
1510                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1511 
1512     if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))) {
1513         return 0;
1514     }
1515 
1516     msg.hdr.request = VHOST_USER_NET_SET_MTU;
1517     msg.payload.u64 = mtu;
1518     msg.hdr.size = sizeof(msg.payload.u64);
1519     msg.hdr.flags = VHOST_USER_VERSION;
1520     if (reply_supported) {
1521         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1522     }
1523 
1524     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1525         return -1;
1526     }
1527 
1528     /* If reply_ack supported, slave has to ack specified MTU is valid */
1529     if (reply_supported) {
1530         return process_message_reply(dev, &msg);
1531     }
1532 
1533     return 0;
1534 }
1535 
1536 static int vhost_user_send_device_iotlb_msg(struct vhost_dev *dev,
1537                                             struct vhost_iotlb_msg *imsg)
1538 {
1539     VhostUserMsg msg = {
1540         .hdr.request = VHOST_USER_IOTLB_MSG,
1541         .hdr.size = sizeof(msg.payload.iotlb),
1542         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1543         .payload.iotlb = *imsg,
1544     };
1545 
1546     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1547         return -EFAULT;
1548     }
1549 
1550     return process_message_reply(dev, &msg);
1551 }
1552 
1553 
1554 static void vhost_user_set_iotlb_callback(struct vhost_dev *dev, int enabled)
1555 {
1556     /* No-op as the receive channel is not dedicated to IOTLB messages. */
1557 }
1558 
1559 static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
1560                                  uint32_t config_len)
1561 {
1562     VhostUserMsg msg = {
1563         .hdr.request = VHOST_USER_GET_CONFIG,
1564         .hdr.flags = VHOST_USER_VERSION,
1565         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + config_len,
1566     };
1567 
1568     if (!virtio_has_feature(dev->protocol_features,
1569                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1570         return -1;
1571     }
1572 
1573     if (config_len > VHOST_USER_MAX_CONFIG_SIZE) {
1574         return -1;
1575     }
1576 
1577     msg.payload.config.offset = 0;
1578     msg.payload.config.size = config_len;
1579     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1580         return -1;
1581     }
1582 
1583     if (vhost_user_read(dev, &msg) < 0) {
1584         return -1;
1585     }
1586 
1587     if (msg.hdr.request != VHOST_USER_GET_CONFIG) {
1588         error_report("Received unexpected msg type. Expected %d received %d",
1589                      VHOST_USER_GET_CONFIG, msg.hdr.request);
1590         return -1;
1591     }
1592 
1593     if (msg.hdr.size != VHOST_USER_CONFIG_HDR_SIZE + config_len) {
1594         error_report("Received bad msg size.");
1595         return -1;
1596     }
1597 
1598     memcpy(config, msg.payload.config.region, config_len);
1599 
1600     return 0;
1601 }
1602 
1603 static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *data,
1604                                  uint32_t offset, uint32_t size, uint32_t flags)
1605 {
1606     uint8_t *p;
1607     bool reply_supported = virtio_has_feature(dev->protocol_features,
1608                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1609 
1610     VhostUserMsg msg = {
1611         .hdr.request = VHOST_USER_SET_CONFIG,
1612         .hdr.flags = VHOST_USER_VERSION,
1613         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + size,
1614     };
1615 
1616     if (!virtio_has_feature(dev->protocol_features,
1617                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1618         return -1;
1619     }
1620 
1621     if (reply_supported) {
1622         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1623     }
1624 
1625     if (size > VHOST_USER_MAX_CONFIG_SIZE) {
1626         return -1;
1627     }
1628 
1629     msg.payload.config.offset = offset,
1630     msg.payload.config.size = size,
1631     msg.payload.config.flags = flags,
1632     p = msg.payload.config.region;
1633     memcpy(p, data, size);
1634 
1635     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1636         return -1;
1637     }
1638 
1639     if (reply_supported) {
1640         return process_message_reply(dev, &msg);
1641     }
1642 
1643     return 0;
1644 }
1645 
1646 static int vhost_user_crypto_create_session(struct vhost_dev *dev,
1647                                             void *session_info,
1648                                             uint64_t *session_id)
1649 {
1650     bool crypto_session = virtio_has_feature(dev->protocol_features,
1651                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1652     CryptoDevBackendSymSessionInfo *sess_info = session_info;
1653     VhostUserMsg msg = {
1654         .hdr.request = VHOST_USER_CREATE_CRYPTO_SESSION,
1655         .hdr.flags = VHOST_USER_VERSION,
1656         .hdr.size = sizeof(msg.payload.session),
1657     };
1658 
1659     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1660 
1661     if (!crypto_session) {
1662         error_report("vhost-user trying to send unhandled ioctl");
1663         return -1;
1664     }
1665 
1666     memcpy(&msg.payload.session.session_setup_data, sess_info,
1667               sizeof(CryptoDevBackendSymSessionInfo));
1668     if (sess_info->key_len) {
1669         memcpy(&msg.payload.session.key, sess_info->cipher_key,
1670                sess_info->key_len);
1671     }
1672     if (sess_info->auth_key_len > 0) {
1673         memcpy(&msg.payload.session.auth_key, sess_info->auth_key,
1674                sess_info->auth_key_len);
1675     }
1676     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1677         error_report("vhost_user_write() return -1, create session failed");
1678         return -1;
1679     }
1680 
1681     if (vhost_user_read(dev, &msg) < 0) {
1682         error_report("vhost_user_read() return -1, create session failed");
1683         return -1;
1684     }
1685 
1686     if (msg.hdr.request != VHOST_USER_CREATE_CRYPTO_SESSION) {
1687         error_report("Received unexpected msg type. Expected %d received %d",
1688                      VHOST_USER_CREATE_CRYPTO_SESSION, msg.hdr.request);
1689         return -1;
1690     }
1691 
1692     if (msg.hdr.size != sizeof(msg.payload.session)) {
1693         error_report("Received bad msg size.");
1694         return -1;
1695     }
1696 
1697     if (msg.payload.session.session_id < 0) {
1698         error_report("Bad session id: %" PRId64 "",
1699                               msg.payload.session.session_id);
1700         return -1;
1701     }
1702     *session_id = msg.payload.session.session_id;
1703 
1704     return 0;
1705 }
1706 
1707 static int
1708 vhost_user_crypto_close_session(struct vhost_dev *dev, uint64_t session_id)
1709 {
1710     bool crypto_session = virtio_has_feature(dev->protocol_features,
1711                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1712     VhostUserMsg msg = {
1713         .hdr.request = VHOST_USER_CLOSE_CRYPTO_SESSION,
1714         .hdr.flags = VHOST_USER_VERSION,
1715         .hdr.size = sizeof(msg.payload.u64),
1716     };
1717     msg.payload.u64 = session_id;
1718 
1719     if (!crypto_session) {
1720         error_report("vhost-user trying to send unhandled ioctl");
1721         return -1;
1722     }
1723 
1724     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1725         error_report("vhost_user_write() return -1, close session failed");
1726         return -1;
1727     }
1728 
1729     return 0;
1730 }
1731 
1732 static bool vhost_user_mem_section_filter(struct vhost_dev *dev,
1733                                           MemoryRegionSection *section)
1734 {
1735     bool result;
1736 
1737     result = memory_region_get_fd(section->mr) >= 0;
1738 
1739     return result;
1740 }
1741 
1742 VhostUserState *vhost_user_init(void)
1743 {
1744     VhostUserState *user = g_new0(struct VhostUserState, 1);
1745 
1746     return user;
1747 }
1748 
1749 void vhost_user_cleanup(VhostUserState *user)
1750 {
1751     int i;
1752 
1753     for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1754         if (user->notifier[i].addr) {
1755             object_unparent(OBJECT(&user->notifier[i].mr));
1756             munmap(user->notifier[i].addr, qemu_real_host_page_size);
1757             user->notifier[i].addr = NULL;
1758         }
1759     }
1760 }
1761 
1762 const VhostOps user_ops = {
1763         .backend_type = VHOST_BACKEND_TYPE_USER,
1764         .vhost_backend_init = vhost_user_backend_init,
1765         .vhost_backend_cleanup = vhost_user_backend_cleanup,
1766         .vhost_backend_memslots_limit = vhost_user_memslots_limit,
1767         .vhost_set_log_base = vhost_user_set_log_base,
1768         .vhost_set_mem_table = vhost_user_set_mem_table,
1769         .vhost_set_vring_addr = vhost_user_set_vring_addr,
1770         .vhost_set_vring_endian = vhost_user_set_vring_endian,
1771         .vhost_set_vring_num = vhost_user_set_vring_num,
1772         .vhost_set_vring_base = vhost_user_set_vring_base,
1773         .vhost_get_vring_base = vhost_user_get_vring_base,
1774         .vhost_set_vring_kick = vhost_user_set_vring_kick,
1775         .vhost_set_vring_call = vhost_user_set_vring_call,
1776         .vhost_set_features = vhost_user_set_features,
1777         .vhost_get_features = vhost_user_get_features,
1778         .vhost_set_owner = vhost_user_set_owner,
1779         .vhost_reset_device = vhost_user_reset_device,
1780         .vhost_get_vq_index = vhost_user_get_vq_index,
1781         .vhost_set_vring_enable = vhost_user_set_vring_enable,
1782         .vhost_requires_shm_log = vhost_user_requires_shm_log,
1783         .vhost_migration_done = vhost_user_migration_done,
1784         .vhost_backend_can_merge = vhost_user_can_merge,
1785         .vhost_net_set_mtu = vhost_user_net_set_mtu,
1786         .vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
1787         .vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
1788         .vhost_get_config = vhost_user_get_config,
1789         .vhost_set_config = vhost_user_set_config,
1790         .vhost_crypto_create_session = vhost_user_crypto_create_session,
1791         .vhost_crypto_close_session = vhost_user_crypto_close_session,
1792         .vhost_backend_mem_section_filter = vhost_user_mem_section_filter,
1793 };
1794