xref: /openbmc/qemu/hw/virtio/vhost-user.c (revision 2a53cff4)
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 
31 #include "standard-headers/linux/vhost_types.h"
32 
33 #ifdef CONFIG_LINUX
34 #include <linux/userfaultfd.h>
35 #endif
36 
37 #define VHOST_MEMORY_MAX_NREGIONS    8
38 #define VHOST_USER_F_PROTOCOL_FEATURES 30
39 #define VHOST_USER_SLAVE_MAX_FDS     8
40 
41 /*
42  * Maximum size of virtio device config space
43  */
44 #define VHOST_USER_MAX_CONFIG_SIZE 256
45 
46 enum VhostUserProtocolFeature {
47     VHOST_USER_PROTOCOL_F_MQ = 0,
48     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
49     VHOST_USER_PROTOCOL_F_RARP = 2,
50     VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
51     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
52     VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
53     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
54     VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
55     VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
56     VHOST_USER_PROTOCOL_F_CONFIG = 9,
57     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
58     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
59     VHOST_USER_PROTOCOL_F_MAX
60 };
61 
62 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
63 
64 typedef enum VhostUserRequest {
65     VHOST_USER_NONE = 0,
66     VHOST_USER_GET_FEATURES = 1,
67     VHOST_USER_SET_FEATURES = 2,
68     VHOST_USER_SET_OWNER = 3,
69     VHOST_USER_RESET_OWNER = 4,
70     VHOST_USER_SET_MEM_TABLE = 5,
71     VHOST_USER_SET_LOG_BASE = 6,
72     VHOST_USER_SET_LOG_FD = 7,
73     VHOST_USER_SET_VRING_NUM = 8,
74     VHOST_USER_SET_VRING_ADDR = 9,
75     VHOST_USER_SET_VRING_BASE = 10,
76     VHOST_USER_GET_VRING_BASE = 11,
77     VHOST_USER_SET_VRING_KICK = 12,
78     VHOST_USER_SET_VRING_CALL = 13,
79     VHOST_USER_SET_VRING_ERR = 14,
80     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
81     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
82     VHOST_USER_GET_QUEUE_NUM = 17,
83     VHOST_USER_SET_VRING_ENABLE = 18,
84     VHOST_USER_SEND_RARP = 19,
85     VHOST_USER_NET_SET_MTU = 20,
86     VHOST_USER_SET_SLAVE_REQ_FD = 21,
87     VHOST_USER_IOTLB_MSG = 22,
88     VHOST_USER_SET_VRING_ENDIAN = 23,
89     VHOST_USER_GET_CONFIG = 24,
90     VHOST_USER_SET_CONFIG = 25,
91     VHOST_USER_CREATE_CRYPTO_SESSION = 26,
92     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
93     VHOST_USER_POSTCOPY_ADVISE  = 28,
94     VHOST_USER_POSTCOPY_LISTEN  = 29,
95     VHOST_USER_POSTCOPY_END     = 30,
96     VHOST_USER_MAX
97 } VhostUserRequest;
98 
99 typedef enum VhostUserSlaveRequest {
100     VHOST_USER_SLAVE_NONE = 0,
101     VHOST_USER_SLAVE_IOTLB_MSG = 1,
102     VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
103     VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
104     VHOST_USER_SLAVE_MAX
105 }  VhostUserSlaveRequest;
106 
107 typedef struct VhostUserMemoryRegion {
108     uint64_t guest_phys_addr;
109     uint64_t memory_size;
110     uint64_t userspace_addr;
111     uint64_t mmap_offset;
112 } VhostUserMemoryRegion;
113 
114 typedef struct VhostUserMemory {
115     uint32_t nregions;
116     uint32_t padding;
117     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
118 } VhostUserMemory;
119 
120 typedef struct VhostUserLog {
121     uint64_t mmap_size;
122     uint64_t mmap_offset;
123 } VhostUserLog;
124 
125 typedef struct VhostUserConfig {
126     uint32_t offset;
127     uint32_t size;
128     uint32_t flags;
129     uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
130 } VhostUserConfig;
131 
132 #define VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN    512
133 #define VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN  64
134 
135 typedef struct VhostUserCryptoSession {
136     /* session id for success, -1 on errors */
137     int64_t session_id;
138     CryptoDevBackendSymSessionInfo session_setup_data;
139     uint8_t key[VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN];
140     uint8_t auth_key[VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN];
141 } VhostUserCryptoSession;
142 
143 static VhostUserConfig c __attribute__ ((unused));
144 #define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
145                                    + sizeof(c.size) \
146                                    + sizeof(c.flags))
147 
148 typedef struct VhostUserVringArea {
149     uint64_t u64;
150     uint64_t size;
151     uint64_t offset;
152 } VhostUserVringArea;
153 
154 typedef struct {
155     VhostUserRequest request;
156 
157 #define VHOST_USER_VERSION_MASK     (0x3)
158 #define VHOST_USER_REPLY_MASK       (0x1<<2)
159 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
160     uint32_t flags;
161     uint32_t size; /* the following payload size */
162 } QEMU_PACKED VhostUserHeader;
163 
164 typedef union {
165 #define VHOST_USER_VRING_IDX_MASK   (0xff)
166 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
167         uint64_t u64;
168         struct vhost_vring_state state;
169         struct vhost_vring_addr addr;
170         VhostUserMemory memory;
171         VhostUserLog log;
172         struct vhost_iotlb_msg iotlb;
173         VhostUserConfig config;
174         VhostUserCryptoSession session;
175         VhostUserVringArea area;
176 } VhostUserPayload;
177 
178 typedef struct VhostUserMsg {
179     VhostUserHeader hdr;
180     VhostUserPayload payload;
181 } QEMU_PACKED VhostUserMsg;
182 
183 static VhostUserMsg m __attribute__ ((unused));
184 #define VHOST_USER_HDR_SIZE (sizeof(VhostUserHeader))
185 
186 #define VHOST_USER_PAYLOAD_SIZE (sizeof(VhostUserPayload))
187 
188 /* The version of the protocol we support */
189 #define VHOST_USER_VERSION    (0x1)
190 
191 struct vhost_user {
192     struct vhost_dev *dev;
193     /* Shared between vhost devs of the same virtio device */
194     VhostUserState *user;
195     int slave_fd;
196     NotifierWithReturn postcopy_notifier;
197     struct PostCopyFD  postcopy_fd;
198     uint64_t           postcopy_client_bases[VHOST_MEMORY_MAX_NREGIONS];
199     /* Length of the region_rb and region_rb_offset arrays */
200     size_t             region_rb_len;
201     /* RAMBlock associated with a given region */
202     RAMBlock         **region_rb;
203     /* The offset from the start of the RAMBlock to the start of the
204      * vhost region.
205      */
206     ram_addr_t        *region_rb_offset;
207 
208     /* True once we've entered postcopy_listen */
209     bool               postcopy_listen;
210 };
211 
212 static bool ioeventfd_enabled(void)
213 {
214     return !kvm_enabled() || kvm_eventfds_enabled();
215 }
216 
217 static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
218 {
219     struct vhost_user *u = dev->opaque;
220     CharBackend *chr = u->user->chr;
221     uint8_t *p = (uint8_t *) msg;
222     int r, size = VHOST_USER_HDR_SIZE;
223 
224     r = qemu_chr_fe_read_all(chr, p, size);
225     if (r != size) {
226         error_report("Failed to read msg header. Read %d instead of %d."
227                      " Original request %d.", r, size, msg->hdr.request);
228         goto fail;
229     }
230 
231     /* validate received flags */
232     if (msg->hdr.flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
233         error_report("Failed to read msg header."
234                 " Flags 0x%x instead of 0x%x.", msg->hdr.flags,
235                 VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
236         goto fail;
237     }
238 
239     /* validate message size is sane */
240     if (msg->hdr.size > VHOST_USER_PAYLOAD_SIZE) {
241         error_report("Failed to read msg header."
242                 " Size %d exceeds the maximum %zu.", msg->hdr.size,
243                 VHOST_USER_PAYLOAD_SIZE);
244         goto fail;
245     }
246 
247     if (msg->hdr.size) {
248         p += VHOST_USER_HDR_SIZE;
249         size = msg->hdr.size;
250         r = qemu_chr_fe_read_all(chr, p, size);
251         if (r != size) {
252             error_report("Failed to read msg payload."
253                          " Read %d instead of %d.", r, msg->hdr.size);
254             goto fail;
255         }
256     }
257 
258     return 0;
259 
260 fail:
261     return -1;
262 }
263 
264 static int process_message_reply(struct vhost_dev *dev,
265                                  const VhostUserMsg *msg)
266 {
267     VhostUserMsg msg_reply;
268 
269     if ((msg->hdr.flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
270         return 0;
271     }
272 
273     if (vhost_user_read(dev, &msg_reply) < 0) {
274         return -1;
275     }
276 
277     if (msg_reply.hdr.request != msg->hdr.request) {
278         error_report("Received unexpected msg type."
279                      "Expected %d received %d",
280                      msg->hdr.request, msg_reply.hdr.request);
281         return -1;
282     }
283 
284     return msg_reply.payload.u64 ? -1 : 0;
285 }
286 
287 static bool vhost_user_one_time_request(VhostUserRequest request)
288 {
289     switch (request) {
290     case VHOST_USER_SET_OWNER:
291     case VHOST_USER_RESET_OWNER:
292     case VHOST_USER_SET_MEM_TABLE:
293     case VHOST_USER_GET_QUEUE_NUM:
294     case VHOST_USER_NET_SET_MTU:
295         return true;
296     default:
297         return false;
298     }
299 }
300 
301 /* most non-init callers ignore the error */
302 static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
303                             int *fds, int fd_num)
304 {
305     struct vhost_user *u = dev->opaque;
306     CharBackend *chr = u->user->chr;
307     int ret, size = VHOST_USER_HDR_SIZE + msg->hdr.size;
308 
309     /*
310      * For non-vring specific requests, like VHOST_USER_SET_MEM_TABLE,
311      * we just need send it once in the first time. For later such
312      * request, we just ignore it.
313      */
314     if (vhost_user_one_time_request(msg->hdr.request) && dev->vq_index != 0) {
315         msg->hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
316         return 0;
317     }
318 
319     if (qemu_chr_fe_set_msgfds(chr, fds, fd_num) < 0) {
320         error_report("Failed to set msg fds.");
321         return -1;
322     }
323 
324     ret = qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size);
325     if (ret != size) {
326         error_report("Failed to write msg."
327                      " Wrote %d instead of %d.", ret, size);
328         return -1;
329     }
330 
331     return 0;
332 }
333 
334 static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
335                                    struct vhost_log *log)
336 {
337     int fds[VHOST_MEMORY_MAX_NREGIONS];
338     size_t fd_num = 0;
339     bool shmfd = virtio_has_feature(dev->protocol_features,
340                                     VHOST_USER_PROTOCOL_F_LOG_SHMFD);
341     VhostUserMsg msg = {
342         .hdr.request = VHOST_USER_SET_LOG_BASE,
343         .hdr.flags = VHOST_USER_VERSION,
344         .payload.log.mmap_size = log->size * sizeof(*(log->log)),
345         .payload.log.mmap_offset = 0,
346         .hdr.size = sizeof(msg.payload.log),
347     };
348 
349     if (shmfd && log->fd != -1) {
350         fds[fd_num++] = log->fd;
351     }
352 
353     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
354         return -1;
355     }
356 
357     if (shmfd) {
358         msg.hdr.size = 0;
359         if (vhost_user_read(dev, &msg) < 0) {
360             return -1;
361         }
362 
363         if (msg.hdr.request != VHOST_USER_SET_LOG_BASE) {
364             error_report("Received unexpected msg type. "
365                          "Expected %d received %d",
366                          VHOST_USER_SET_LOG_BASE, msg.hdr.request);
367             return -1;
368         }
369     }
370 
371     return 0;
372 }
373 
374 static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
375                                              struct vhost_memory *mem)
376 {
377     struct vhost_user *u = dev->opaque;
378     int fds[VHOST_MEMORY_MAX_NREGIONS];
379     int i, fd;
380     size_t fd_num = 0;
381     VhostUserMsg msg_reply;
382     int region_i, msg_i;
383 
384     VhostUserMsg msg = {
385         .hdr.request = VHOST_USER_SET_MEM_TABLE,
386         .hdr.flags = VHOST_USER_VERSION,
387     };
388 
389     if (u->region_rb_len < dev->mem->nregions) {
390         u->region_rb = g_renew(RAMBlock*, u->region_rb, dev->mem->nregions);
391         u->region_rb_offset = g_renew(ram_addr_t, u->region_rb_offset,
392                                       dev->mem->nregions);
393         memset(&(u->region_rb[u->region_rb_len]), '\0',
394                sizeof(RAMBlock *) * (dev->mem->nregions - u->region_rb_len));
395         memset(&(u->region_rb_offset[u->region_rb_len]), '\0',
396                sizeof(ram_addr_t) * (dev->mem->nregions - u->region_rb_len));
397         u->region_rb_len = dev->mem->nregions;
398     }
399 
400     for (i = 0; i < dev->mem->nregions; ++i) {
401         struct vhost_memory_region *reg = dev->mem->regions + i;
402         ram_addr_t offset;
403         MemoryRegion *mr;
404 
405         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
406         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
407                                      &offset);
408         fd = memory_region_get_fd(mr);
409         if (fd > 0) {
410             trace_vhost_user_set_mem_table_withfd(fd_num, mr->name,
411                                                   reg->memory_size,
412                                                   reg->guest_phys_addr,
413                                                   reg->userspace_addr, offset);
414             u->region_rb_offset[i] = offset;
415             u->region_rb[i] = mr->ram_block;
416             msg.payload.memory.regions[fd_num].userspace_addr =
417                 reg->userspace_addr;
418             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
419             msg.payload.memory.regions[fd_num].guest_phys_addr =
420                 reg->guest_phys_addr;
421             msg.payload.memory.regions[fd_num].mmap_offset = offset;
422             assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
423             fds[fd_num++] = fd;
424         } else {
425             u->region_rb_offset[i] = 0;
426             u->region_rb[i] = NULL;
427         }
428     }
429 
430     msg.payload.memory.nregions = fd_num;
431 
432     if (!fd_num) {
433         error_report("Failed initializing vhost-user memory map, "
434                      "consider using -object memory-backend-file share=on");
435         return -1;
436     }
437 
438     msg.hdr.size = sizeof(msg.payload.memory.nregions);
439     msg.hdr.size += sizeof(msg.payload.memory.padding);
440     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
441 
442     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
443         return -1;
444     }
445 
446     if (vhost_user_read(dev, &msg_reply) < 0) {
447         return -1;
448     }
449 
450     if (msg_reply.hdr.request != VHOST_USER_SET_MEM_TABLE) {
451         error_report("%s: Received unexpected msg type."
452                      "Expected %d received %d", __func__,
453                      VHOST_USER_SET_MEM_TABLE, msg_reply.hdr.request);
454         return -1;
455     }
456     /* We're using the same structure, just reusing one of the
457      * fields, so it should be the same size.
458      */
459     if (msg_reply.hdr.size != msg.hdr.size) {
460         error_report("%s: Unexpected size for postcopy reply "
461                      "%d vs %d", __func__, msg_reply.hdr.size, msg.hdr.size);
462         return -1;
463     }
464 
465     memset(u->postcopy_client_bases, 0,
466            sizeof(uint64_t) * VHOST_MEMORY_MAX_NREGIONS);
467 
468     /* They're in the same order as the regions that were sent
469      * but some of the regions were skipped (above) if they
470      * didn't have fd's
471     */
472     for (msg_i = 0, region_i = 0;
473          region_i < dev->mem->nregions;
474         region_i++) {
475         if (msg_i < fd_num &&
476             msg_reply.payload.memory.regions[msg_i].guest_phys_addr ==
477             dev->mem->regions[region_i].guest_phys_addr) {
478             u->postcopy_client_bases[region_i] =
479                 msg_reply.payload.memory.regions[msg_i].userspace_addr;
480             trace_vhost_user_set_mem_table_postcopy(
481                 msg_reply.payload.memory.regions[msg_i].userspace_addr,
482                 msg.payload.memory.regions[msg_i].userspace_addr,
483                 msg_i, region_i);
484             msg_i++;
485         }
486     }
487     if (msg_i != fd_num) {
488         error_report("%s: postcopy reply not fully consumed "
489                      "%d vs %zd",
490                      __func__, msg_i, fd_num);
491         return -1;
492     }
493     /* Now we've registered this with the postcopy code, we ack to the client,
494      * because now we're in the position to be able to deal with any faults
495      * it generates.
496      */
497     /* TODO: Use this for failure cases as well with a bad value */
498     msg.hdr.size = sizeof(msg.payload.u64);
499     msg.payload.u64 = 0; /* OK */
500     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
501         return -1;
502     }
503 
504     return 0;
505 }
506 
507 static int vhost_user_set_mem_table(struct vhost_dev *dev,
508                                     struct vhost_memory *mem)
509 {
510     struct vhost_user *u = dev->opaque;
511     int fds[VHOST_MEMORY_MAX_NREGIONS];
512     int i, fd;
513     size_t fd_num = 0;
514     bool do_postcopy = u->postcopy_listen && u->postcopy_fd.handler;
515     bool reply_supported = virtio_has_feature(dev->protocol_features,
516                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
517 
518     if (do_postcopy) {
519         /* Postcopy has enough differences that it's best done in it's own
520          * version
521          */
522         return vhost_user_set_mem_table_postcopy(dev, mem);
523     }
524 
525     VhostUserMsg msg = {
526         .hdr.request = VHOST_USER_SET_MEM_TABLE,
527         .hdr.flags = VHOST_USER_VERSION,
528     };
529 
530     if (reply_supported) {
531         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
532     }
533 
534     for (i = 0; i < dev->mem->nregions; ++i) {
535         struct vhost_memory_region *reg = dev->mem->regions + i;
536         ram_addr_t offset;
537         MemoryRegion *mr;
538 
539         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
540         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
541                                      &offset);
542         fd = memory_region_get_fd(mr);
543         if (fd > 0) {
544             if (fd_num == VHOST_MEMORY_MAX_NREGIONS) {
545                 error_report("Failed preparing vhost-user memory table msg");
546                 return -1;
547             }
548             msg.payload.memory.regions[fd_num].userspace_addr =
549                 reg->userspace_addr;
550             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
551             msg.payload.memory.regions[fd_num].guest_phys_addr =
552                 reg->guest_phys_addr;
553             msg.payload.memory.regions[fd_num].mmap_offset = offset;
554             fds[fd_num++] = fd;
555         }
556     }
557 
558     msg.payload.memory.nregions = fd_num;
559 
560     if (!fd_num) {
561         error_report("Failed initializing vhost-user memory map, "
562                      "consider using -object memory-backend-file share=on");
563         return -1;
564     }
565 
566     msg.hdr.size = sizeof(msg.payload.memory.nregions);
567     msg.hdr.size += sizeof(msg.payload.memory.padding);
568     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
569 
570     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
571         return -1;
572     }
573 
574     if (reply_supported) {
575         return process_message_reply(dev, &msg);
576     }
577 
578     return 0;
579 }
580 
581 static int vhost_user_set_vring_addr(struct vhost_dev *dev,
582                                      struct vhost_vring_addr *addr)
583 {
584     VhostUserMsg msg = {
585         .hdr.request = VHOST_USER_SET_VRING_ADDR,
586         .hdr.flags = VHOST_USER_VERSION,
587         .payload.addr = *addr,
588         .hdr.size = sizeof(msg.payload.addr),
589     };
590 
591     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
592         return -1;
593     }
594 
595     return 0;
596 }
597 
598 static int vhost_user_set_vring_endian(struct vhost_dev *dev,
599                                        struct vhost_vring_state *ring)
600 {
601     bool cross_endian = virtio_has_feature(dev->protocol_features,
602                                            VHOST_USER_PROTOCOL_F_CROSS_ENDIAN);
603     VhostUserMsg msg = {
604         .hdr.request = VHOST_USER_SET_VRING_ENDIAN,
605         .hdr.flags = VHOST_USER_VERSION,
606         .payload.state = *ring,
607         .hdr.size = sizeof(msg.payload.state),
608     };
609 
610     if (!cross_endian) {
611         error_report("vhost-user trying to send unhandled ioctl");
612         return -1;
613     }
614 
615     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
616         return -1;
617     }
618 
619     return 0;
620 }
621 
622 static int vhost_set_vring(struct vhost_dev *dev,
623                            unsigned long int request,
624                            struct vhost_vring_state *ring)
625 {
626     VhostUserMsg msg = {
627         .hdr.request = request,
628         .hdr.flags = VHOST_USER_VERSION,
629         .payload.state = *ring,
630         .hdr.size = sizeof(msg.payload.state),
631     };
632 
633     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
634         return -1;
635     }
636 
637     return 0;
638 }
639 
640 static int vhost_user_set_vring_num(struct vhost_dev *dev,
641                                     struct vhost_vring_state *ring)
642 {
643     return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
644 }
645 
646 static void vhost_user_host_notifier_restore(struct vhost_dev *dev,
647                                              int queue_idx)
648 {
649     struct vhost_user *u = dev->opaque;
650     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
651     VirtIODevice *vdev = dev->vdev;
652 
653     if (n->addr && !n->set) {
654         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true);
655         n->set = true;
656     }
657 }
658 
659 static void vhost_user_host_notifier_remove(struct vhost_dev *dev,
660                                             int queue_idx)
661 {
662     struct vhost_user *u = dev->opaque;
663     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
664     VirtIODevice *vdev = dev->vdev;
665 
666     if (n->addr && n->set) {
667         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
668         n->set = false;
669     }
670 }
671 
672 static int vhost_user_set_vring_base(struct vhost_dev *dev,
673                                      struct vhost_vring_state *ring)
674 {
675     vhost_user_host_notifier_restore(dev, ring->index);
676 
677     return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
678 }
679 
680 static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
681 {
682     int i;
683 
684     if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
685         return -1;
686     }
687 
688     for (i = 0; i < dev->nvqs; ++i) {
689         struct vhost_vring_state state = {
690             .index = dev->vq_index + i,
691             .num   = enable,
692         };
693 
694         vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
695     }
696 
697     return 0;
698 }
699 
700 static int vhost_user_get_vring_base(struct vhost_dev *dev,
701                                      struct vhost_vring_state *ring)
702 {
703     VhostUserMsg msg = {
704         .hdr.request = VHOST_USER_GET_VRING_BASE,
705         .hdr.flags = VHOST_USER_VERSION,
706         .payload.state = *ring,
707         .hdr.size = sizeof(msg.payload.state),
708     };
709 
710     vhost_user_host_notifier_remove(dev, ring->index);
711 
712     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
713         return -1;
714     }
715 
716     if (vhost_user_read(dev, &msg) < 0) {
717         return -1;
718     }
719 
720     if (msg.hdr.request != VHOST_USER_GET_VRING_BASE) {
721         error_report("Received unexpected msg type. Expected %d received %d",
722                      VHOST_USER_GET_VRING_BASE, msg.hdr.request);
723         return -1;
724     }
725 
726     if (msg.hdr.size != sizeof(msg.payload.state)) {
727         error_report("Received bad msg size.");
728         return -1;
729     }
730 
731     *ring = msg.payload.state;
732 
733     return 0;
734 }
735 
736 static int vhost_set_vring_file(struct vhost_dev *dev,
737                                 VhostUserRequest request,
738                                 struct vhost_vring_file *file)
739 {
740     int fds[VHOST_MEMORY_MAX_NREGIONS];
741     size_t fd_num = 0;
742     VhostUserMsg msg = {
743         .hdr.request = request,
744         .hdr.flags = VHOST_USER_VERSION,
745         .payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
746         .hdr.size = sizeof(msg.payload.u64),
747     };
748 
749     if (ioeventfd_enabled() && file->fd > 0) {
750         fds[fd_num++] = file->fd;
751     } else {
752         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
753     }
754 
755     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
756         return -1;
757     }
758 
759     return 0;
760 }
761 
762 static int vhost_user_set_vring_kick(struct vhost_dev *dev,
763                                      struct vhost_vring_file *file)
764 {
765     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
766 }
767 
768 static int vhost_user_set_vring_call(struct vhost_dev *dev,
769                                      struct vhost_vring_file *file)
770 {
771     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
772 }
773 
774 static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64)
775 {
776     VhostUserMsg msg = {
777         .hdr.request = request,
778         .hdr.flags = VHOST_USER_VERSION,
779         .payload.u64 = u64,
780         .hdr.size = sizeof(msg.payload.u64),
781     };
782 
783     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
784         return -1;
785     }
786 
787     return 0;
788 }
789 
790 static int vhost_user_set_features(struct vhost_dev *dev,
791                                    uint64_t features)
792 {
793     return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features);
794 }
795 
796 static int vhost_user_set_protocol_features(struct vhost_dev *dev,
797                                             uint64_t features)
798 {
799     return vhost_user_set_u64(dev, VHOST_USER_SET_PROTOCOL_FEATURES, features);
800 }
801 
802 static int vhost_user_get_u64(struct vhost_dev *dev, int request, uint64_t *u64)
803 {
804     VhostUserMsg msg = {
805         .hdr.request = request,
806         .hdr.flags = VHOST_USER_VERSION,
807     };
808 
809     if (vhost_user_one_time_request(request) && dev->vq_index != 0) {
810         return 0;
811     }
812 
813     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
814         return -1;
815     }
816 
817     if (vhost_user_read(dev, &msg) < 0) {
818         return -1;
819     }
820 
821     if (msg.hdr.request != request) {
822         error_report("Received unexpected msg type. Expected %d received %d",
823                      request, msg.hdr.request);
824         return -1;
825     }
826 
827     if (msg.hdr.size != sizeof(msg.payload.u64)) {
828         error_report("Received bad msg size.");
829         return -1;
830     }
831 
832     *u64 = msg.payload.u64;
833 
834     return 0;
835 }
836 
837 static int vhost_user_get_features(struct vhost_dev *dev, uint64_t *features)
838 {
839     return vhost_user_get_u64(dev, VHOST_USER_GET_FEATURES, features);
840 }
841 
842 static int vhost_user_set_owner(struct vhost_dev *dev)
843 {
844     VhostUserMsg msg = {
845         .hdr.request = VHOST_USER_SET_OWNER,
846         .hdr.flags = VHOST_USER_VERSION,
847     };
848 
849     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
850         return -1;
851     }
852 
853     return 0;
854 }
855 
856 static int vhost_user_reset_device(struct vhost_dev *dev)
857 {
858     VhostUserMsg msg = {
859         .hdr.request = VHOST_USER_RESET_OWNER,
860         .hdr.flags = VHOST_USER_VERSION,
861     };
862 
863     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
864         return -1;
865     }
866 
867     return 0;
868 }
869 
870 static int vhost_user_slave_handle_config_change(struct vhost_dev *dev)
871 {
872     int ret = -1;
873 
874     if (!dev->config_ops) {
875         return -1;
876     }
877 
878     if (dev->config_ops->vhost_dev_config_notifier) {
879         ret = dev->config_ops->vhost_dev_config_notifier(dev);
880     }
881 
882     return ret;
883 }
884 
885 static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev,
886                                                        VhostUserVringArea *area,
887                                                        int fd)
888 {
889     int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK;
890     size_t page_size = qemu_real_host_page_size;
891     struct vhost_user *u = dev->opaque;
892     VhostUserState *user = u->user;
893     VirtIODevice *vdev = dev->vdev;
894     VhostUserHostNotifier *n;
895     void *addr;
896     char *name;
897 
898     if (!virtio_has_feature(dev->protocol_features,
899                             VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) ||
900         vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) {
901         return -1;
902     }
903 
904     n = &user->notifier[queue_idx];
905 
906     if (n->addr) {
907         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
908         object_unparent(OBJECT(&n->mr));
909         munmap(n->addr, page_size);
910         n->addr = NULL;
911     }
912 
913     if (area->u64 & VHOST_USER_VRING_NOFD_MASK) {
914         return 0;
915     }
916 
917     /* Sanity check. */
918     if (area->size != page_size) {
919         return -1;
920     }
921 
922     addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
923                 fd, area->offset);
924     if (addr == MAP_FAILED) {
925         return -1;
926     }
927 
928     name = g_strdup_printf("vhost-user/host-notifier@%p mmaps[%d]",
929                            user, queue_idx);
930     memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name,
931                                       page_size, addr);
932     g_free(name);
933 
934     if (virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true)) {
935         munmap(addr, page_size);
936         return -1;
937     }
938 
939     n->addr = addr;
940     n->set = true;
941 
942     return 0;
943 }
944 
945 static void slave_read(void *opaque)
946 {
947     struct vhost_dev *dev = opaque;
948     struct vhost_user *u = dev->opaque;
949     VhostUserHeader hdr = { 0, };
950     VhostUserPayload payload = { 0, };
951     int size, ret = 0;
952     struct iovec iov;
953     struct msghdr msgh;
954     int fd[VHOST_USER_SLAVE_MAX_FDS];
955     char control[CMSG_SPACE(sizeof(fd))];
956     struct cmsghdr *cmsg;
957     int i, fdsize = 0;
958 
959     memset(&msgh, 0, sizeof(msgh));
960     msgh.msg_iov = &iov;
961     msgh.msg_iovlen = 1;
962     msgh.msg_control = control;
963     msgh.msg_controllen = sizeof(control);
964 
965     memset(fd, -1, sizeof(fd));
966 
967     /* Read header */
968     iov.iov_base = &hdr;
969     iov.iov_len = VHOST_USER_HDR_SIZE;
970 
971     size = recvmsg(u->slave_fd, &msgh, 0);
972     if (size != VHOST_USER_HDR_SIZE) {
973         error_report("Failed to read from slave.");
974         goto err;
975     }
976 
977     if (msgh.msg_flags & MSG_CTRUNC) {
978         error_report("Truncated message.");
979         goto err;
980     }
981 
982     for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;
983          cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
984             if (cmsg->cmsg_level == SOL_SOCKET &&
985                 cmsg->cmsg_type == SCM_RIGHTS) {
986                     fdsize = cmsg->cmsg_len - CMSG_LEN(0);
987                     memcpy(fd, CMSG_DATA(cmsg), fdsize);
988                     break;
989             }
990     }
991 
992     if (hdr.size > VHOST_USER_PAYLOAD_SIZE) {
993         error_report("Failed to read msg header."
994                 " Size %d exceeds the maximum %zu.", hdr.size,
995                 VHOST_USER_PAYLOAD_SIZE);
996         goto err;
997     }
998 
999     /* Read payload */
1000     size = read(u->slave_fd, &payload, hdr.size);
1001     if (size != hdr.size) {
1002         error_report("Failed to read payload from slave.");
1003         goto err;
1004     }
1005 
1006     switch (hdr.request) {
1007     case VHOST_USER_SLAVE_IOTLB_MSG:
1008         ret = vhost_backend_handle_iotlb_msg(dev, &payload.iotlb);
1009         break;
1010     case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG :
1011         ret = vhost_user_slave_handle_config_change(dev);
1012         break;
1013     case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
1014         ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area,
1015                                                           fd[0]);
1016         break;
1017     default:
1018         error_report("Received unexpected msg type.");
1019         ret = -EINVAL;
1020     }
1021 
1022     /* Close the remaining file descriptors. */
1023     for (i = 0; i < fdsize; i++) {
1024         if (fd[i] != -1) {
1025             close(fd[i]);
1026         }
1027     }
1028 
1029     /*
1030      * REPLY_ACK feature handling. Other reply types has to be managed
1031      * directly in their request handlers.
1032      */
1033     if (hdr.flags & VHOST_USER_NEED_REPLY_MASK) {
1034         struct iovec iovec[2];
1035 
1036 
1037         hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
1038         hdr.flags |= VHOST_USER_REPLY_MASK;
1039 
1040         payload.u64 = !!ret;
1041         hdr.size = sizeof(payload.u64);
1042 
1043         iovec[0].iov_base = &hdr;
1044         iovec[0].iov_len = VHOST_USER_HDR_SIZE;
1045         iovec[1].iov_base = &payload;
1046         iovec[1].iov_len = hdr.size;
1047 
1048         size = writev(u->slave_fd, iovec, ARRAY_SIZE(iovec));
1049         if (size != VHOST_USER_HDR_SIZE + hdr.size) {
1050             error_report("Failed to send msg reply to slave.");
1051             goto err;
1052         }
1053     }
1054 
1055     return;
1056 
1057 err:
1058     qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1059     close(u->slave_fd);
1060     u->slave_fd = -1;
1061     for (i = 0; i < fdsize; i++) {
1062         if (fd[i] != -1) {
1063             close(fd[i]);
1064         }
1065     }
1066     return;
1067 }
1068 
1069 static int vhost_setup_slave_channel(struct vhost_dev *dev)
1070 {
1071     VhostUserMsg msg = {
1072         .hdr.request = VHOST_USER_SET_SLAVE_REQ_FD,
1073         .hdr.flags = VHOST_USER_VERSION,
1074     };
1075     struct vhost_user *u = dev->opaque;
1076     int sv[2], ret = 0;
1077     bool reply_supported = virtio_has_feature(dev->protocol_features,
1078                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1079 
1080     if (!virtio_has_feature(dev->protocol_features,
1081                             VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
1082         return 0;
1083     }
1084 
1085     if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
1086         error_report("socketpair() failed");
1087         return -1;
1088     }
1089 
1090     u->slave_fd = sv[0];
1091     qemu_set_fd_handler(u->slave_fd, slave_read, NULL, dev);
1092 
1093     if (reply_supported) {
1094         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1095     }
1096 
1097     ret = vhost_user_write(dev, &msg, &sv[1], 1);
1098     if (ret) {
1099         goto out;
1100     }
1101 
1102     if (reply_supported) {
1103         ret = process_message_reply(dev, &msg);
1104     }
1105 
1106 out:
1107     close(sv[1]);
1108     if (ret) {
1109         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1110         close(u->slave_fd);
1111         u->slave_fd = -1;
1112     }
1113 
1114     return ret;
1115 }
1116 
1117 #ifdef CONFIG_LINUX
1118 /*
1119  * Called back from the postcopy fault thread when a fault is received on our
1120  * ufd.
1121  * TODO: This is Linux specific
1122  */
1123 static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
1124                                              void *ufd)
1125 {
1126     struct vhost_dev *dev = pcfd->data;
1127     struct vhost_user *u = dev->opaque;
1128     struct uffd_msg *msg = ufd;
1129     uint64_t faultaddr = msg->arg.pagefault.address;
1130     RAMBlock *rb = NULL;
1131     uint64_t rb_offset;
1132     int i;
1133 
1134     trace_vhost_user_postcopy_fault_handler(pcfd->idstr, faultaddr,
1135                                             dev->mem->nregions);
1136     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1137         trace_vhost_user_postcopy_fault_handler_loop(i,
1138                 u->postcopy_client_bases[i], dev->mem->regions[i].memory_size);
1139         if (faultaddr >= u->postcopy_client_bases[i]) {
1140             /* Ofset of the fault address in the vhost region */
1141             uint64_t region_offset = faultaddr - u->postcopy_client_bases[i];
1142             if (region_offset < dev->mem->regions[i].memory_size) {
1143                 rb_offset = region_offset + u->region_rb_offset[i];
1144                 trace_vhost_user_postcopy_fault_handler_found(i,
1145                         region_offset, rb_offset);
1146                 rb = u->region_rb[i];
1147                 return postcopy_request_shared_page(pcfd, rb, faultaddr,
1148                                                     rb_offset);
1149             }
1150         }
1151     }
1152     error_report("%s: Failed to find region for fault %" PRIx64,
1153                  __func__, faultaddr);
1154     return -1;
1155 }
1156 
1157 static int vhost_user_postcopy_waker(struct PostCopyFD *pcfd, RAMBlock *rb,
1158                                      uint64_t offset)
1159 {
1160     struct vhost_dev *dev = pcfd->data;
1161     struct vhost_user *u = dev->opaque;
1162     int i;
1163 
1164     trace_vhost_user_postcopy_waker(qemu_ram_get_idstr(rb), offset);
1165 
1166     if (!u) {
1167         return 0;
1168     }
1169     /* Translate the offset into an address in the clients address space */
1170     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1171         if (u->region_rb[i] == rb &&
1172             offset >= u->region_rb_offset[i] &&
1173             offset < (u->region_rb_offset[i] +
1174                       dev->mem->regions[i].memory_size)) {
1175             uint64_t client_addr = (offset - u->region_rb_offset[i]) +
1176                                    u->postcopy_client_bases[i];
1177             trace_vhost_user_postcopy_waker_found(client_addr);
1178             return postcopy_wake_shared(pcfd, client_addr, rb);
1179         }
1180     }
1181 
1182     trace_vhost_user_postcopy_waker_nomatch(qemu_ram_get_idstr(rb), offset);
1183     return 0;
1184 }
1185 #endif
1186 
1187 /*
1188  * Called at the start of an inbound postcopy on reception of the
1189  * 'advise' command.
1190  */
1191 static int vhost_user_postcopy_advise(struct vhost_dev *dev, Error **errp)
1192 {
1193 #ifdef CONFIG_LINUX
1194     struct vhost_user *u = dev->opaque;
1195     CharBackend *chr = u->user->chr;
1196     int ufd;
1197     VhostUserMsg msg = {
1198         .hdr.request = VHOST_USER_POSTCOPY_ADVISE,
1199         .hdr.flags = VHOST_USER_VERSION,
1200     };
1201 
1202     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1203         error_setg(errp, "Failed to send postcopy_advise to vhost");
1204         return -1;
1205     }
1206 
1207     if (vhost_user_read(dev, &msg) < 0) {
1208         error_setg(errp, "Failed to get postcopy_advise reply from vhost");
1209         return -1;
1210     }
1211 
1212     if (msg.hdr.request != VHOST_USER_POSTCOPY_ADVISE) {
1213         error_setg(errp, "Unexpected msg type. Expected %d received %d",
1214                      VHOST_USER_POSTCOPY_ADVISE, msg.hdr.request);
1215         return -1;
1216     }
1217 
1218     if (msg.hdr.size) {
1219         error_setg(errp, "Received bad msg size.");
1220         return -1;
1221     }
1222     ufd = qemu_chr_fe_get_msgfd(chr);
1223     if (ufd < 0) {
1224         error_setg(errp, "%s: Failed to get ufd", __func__);
1225         return -1;
1226     }
1227     qemu_set_nonblock(ufd);
1228 
1229     /* register ufd with userfault thread */
1230     u->postcopy_fd.fd = ufd;
1231     u->postcopy_fd.data = dev;
1232     u->postcopy_fd.handler = vhost_user_postcopy_fault_handler;
1233     u->postcopy_fd.waker = vhost_user_postcopy_waker;
1234     u->postcopy_fd.idstr = "vhost-user"; /* Need to find unique name */
1235     postcopy_register_shared_ufd(&u->postcopy_fd);
1236     return 0;
1237 #else
1238     error_setg(errp, "Postcopy not supported on non-Linux systems");
1239     return -1;
1240 #endif
1241 }
1242 
1243 /*
1244  * Called at the switch to postcopy on reception of the 'listen' command.
1245  */
1246 static int vhost_user_postcopy_listen(struct vhost_dev *dev, Error **errp)
1247 {
1248     struct vhost_user *u = dev->opaque;
1249     int ret;
1250     VhostUserMsg msg = {
1251         .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
1252         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1253     };
1254     u->postcopy_listen = true;
1255     trace_vhost_user_postcopy_listen();
1256     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1257         error_setg(errp, "Failed to send postcopy_listen to vhost");
1258         return -1;
1259     }
1260 
1261     ret = process_message_reply(dev, &msg);
1262     if (ret) {
1263         error_setg(errp, "Failed to receive reply to postcopy_listen");
1264         return ret;
1265     }
1266 
1267     return 0;
1268 }
1269 
1270 /*
1271  * Called at the end of postcopy
1272  */
1273 static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
1274 {
1275     VhostUserMsg msg = {
1276         .hdr.request = VHOST_USER_POSTCOPY_END,
1277         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1278     };
1279     int ret;
1280     struct vhost_user *u = dev->opaque;
1281 
1282     trace_vhost_user_postcopy_end_entry();
1283     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1284         error_setg(errp, "Failed to send postcopy_end to vhost");
1285         return -1;
1286     }
1287 
1288     ret = process_message_reply(dev, &msg);
1289     if (ret) {
1290         error_setg(errp, "Failed to receive reply to postcopy_end");
1291         return ret;
1292     }
1293     postcopy_unregister_shared_ufd(&u->postcopy_fd);
1294     close(u->postcopy_fd.fd);
1295     u->postcopy_fd.handler = NULL;
1296 
1297     trace_vhost_user_postcopy_end_exit();
1298 
1299     return 0;
1300 }
1301 
1302 static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
1303                                         void *opaque)
1304 {
1305     struct PostcopyNotifyData *pnd = opaque;
1306     struct vhost_user *u = container_of(notifier, struct vhost_user,
1307                                          postcopy_notifier);
1308     struct vhost_dev *dev = u->dev;
1309 
1310     switch (pnd->reason) {
1311     case POSTCOPY_NOTIFY_PROBE:
1312         if (!virtio_has_feature(dev->protocol_features,
1313                                 VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
1314             /* TODO: Get the device name into this error somehow */
1315             error_setg(pnd->errp,
1316                        "vhost-user backend not capable of postcopy");
1317             return -ENOENT;
1318         }
1319         break;
1320 
1321     case POSTCOPY_NOTIFY_INBOUND_ADVISE:
1322         return vhost_user_postcopy_advise(dev, pnd->errp);
1323 
1324     case POSTCOPY_NOTIFY_INBOUND_LISTEN:
1325         return vhost_user_postcopy_listen(dev, pnd->errp);
1326 
1327     case POSTCOPY_NOTIFY_INBOUND_END:
1328         return vhost_user_postcopy_end(dev, pnd->errp);
1329 
1330     default:
1331         /* We ignore notifications we don't know */
1332         break;
1333     }
1334 
1335     return 0;
1336 }
1337 
1338 static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque)
1339 {
1340     uint64_t features, protocol_features;
1341     struct vhost_user *u;
1342     int err;
1343 
1344     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1345 
1346     u = g_new0(struct vhost_user, 1);
1347     u->user = opaque;
1348     u->slave_fd = -1;
1349     u->dev = dev;
1350     dev->opaque = u;
1351 
1352     err = vhost_user_get_features(dev, &features);
1353     if (err < 0) {
1354         return err;
1355     }
1356 
1357     if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
1358         dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
1359 
1360         err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
1361                                  &protocol_features);
1362         if (err < 0) {
1363             return err;
1364         }
1365 
1366         dev->protocol_features =
1367             protocol_features & VHOST_USER_PROTOCOL_FEATURE_MASK;
1368 
1369         if (!dev->config_ops || !dev->config_ops->vhost_dev_config_notifier) {
1370             /* Don't acknowledge CONFIG feature if device doesn't support it */
1371             dev->protocol_features &= ~(1ULL << VHOST_USER_PROTOCOL_F_CONFIG);
1372         } else if (!(protocol_features &
1373                     (1ULL << VHOST_USER_PROTOCOL_F_CONFIG))) {
1374             error_report("Device expects VHOST_USER_PROTOCOL_F_CONFIG "
1375                     "but backend does not support it.");
1376             return -1;
1377         }
1378 
1379         err = vhost_user_set_protocol_features(dev, dev->protocol_features);
1380         if (err < 0) {
1381             return err;
1382         }
1383 
1384         /* query the max queues we support if backend supports Multiple Queue */
1385         if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
1386             err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
1387                                      &dev->max_queues);
1388             if (err < 0) {
1389                 return err;
1390             }
1391         }
1392 
1393         if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) &&
1394                 !(virtio_has_feature(dev->protocol_features,
1395                     VHOST_USER_PROTOCOL_F_SLAVE_REQ) &&
1396                  virtio_has_feature(dev->protocol_features,
1397                     VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1398             error_report("IOMMU support requires reply-ack and "
1399                          "slave-req protocol features.");
1400             return -1;
1401         }
1402     }
1403 
1404     if (dev->migration_blocker == NULL &&
1405         !virtio_has_feature(dev->protocol_features,
1406                             VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
1407         error_setg(&dev->migration_blocker,
1408                    "Migration disabled: vhost-user backend lacks "
1409                    "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
1410     }
1411 
1412     err = vhost_setup_slave_channel(dev);
1413     if (err < 0) {
1414         return err;
1415     }
1416 
1417     u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
1418     postcopy_add_notifier(&u->postcopy_notifier);
1419 
1420     return 0;
1421 }
1422 
1423 static int vhost_user_backend_cleanup(struct vhost_dev *dev)
1424 {
1425     struct vhost_user *u;
1426 
1427     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1428 
1429     u = dev->opaque;
1430     if (u->postcopy_notifier.notify) {
1431         postcopy_remove_notifier(&u->postcopy_notifier);
1432         u->postcopy_notifier.notify = NULL;
1433     }
1434     u->postcopy_listen = false;
1435     if (u->postcopy_fd.handler) {
1436         postcopy_unregister_shared_ufd(&u->postcopy_fd);
1437         close(u->postcopy_fd.fd);
1438         u->postcopy_fd.handler = NULL;
1439     }
1440     if (u->slave_fd >= 0) {
1441         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1442         close(u->slave_fd);
1443         u->slave_fd = -1;
1444     }
1445     g_free(u->region_rb);
1446     u->region_rb = NULL;
1447     g_free(u->region_rb_offset);
1448     u->region_rb_offset = NULL;
1449     u->region_rb_len = 0;
1450     g_free(u);
1451     dev->opaque = 0;
1452 
1453     return 0;
1454 }
1455 
1456 static int vhost_user_get_vq_index(struct vhost_dev *dev, int idx)
1457 {
1458     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
1459 
1460     return idx;
1461 }
1462 
1463 static int vhost_user_memslots_limit(struct vhost_dev *dev)
1464 {
1465     return VHOST_MEMORY_MAX_NREGIONS;
1466 }
1467 
1468 static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
1469 {
1470     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1471 
1472     return virtio_has_feature(dev->protocol_features,
1473                               VHOST_USER_PROTOCOL_F_LOG_SHMFD);
1474 }
1475 
1476 static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
1477 {
1478     VhostUserMsg msg = { };
1479 
1480     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1481 
1482     /* If guest supports GUEST_ANNOUNCE do nothing */
1483     if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {
1484         return 0;
1485     }
1486 
1487     /* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
1488     if (virtio_has_feature(dev->protocol_features,
1489                            VHOST_USER_PROTOCOL_F_RARP)) {
1490         msg.hdr.request = VHOST_USER_SEND_RARP;
1491         msg.hdr.flags = VHOST_USER_VERSION;
1492         memcpy((char *)&msg.payload.u64, mac_addr, 6);
1493         msg.hdr.size = sizeof(msg.payload.u64);
1494 
1495         return vhost_user_write(dev, &msg, NULL, 0);
1496     }
1497     return -1;
1498 }
1499 
1500 static bool vhost_user_can_merge(struct vhost_dev *dev,
1501                                  uint64_t start1, uint64_t size1,
1502                                  uint64_t start2, uint64_t size2)
1503 {
1504     ram_addr_t offset;
1505     int mfd, rfd;
1506     MemoryRegion *mr;
1507 
1508     mr = memory_region_from_host((void *)(uintptr_t)start1, &offset);
1509     mfd = memory_region_get_fd(mr);
1510 
1511     mr = memory_region_from_host((void *)(uintptr_t)start2, &offset);
1512     rfd = memory_region_get_fd(mr);
1513 
1514     return mfd == rfd;
1515 }
1516 
1517 static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu)
1518 {
1519     VhostUserMsg msg;
1520     bool reply_supported = virtio_has_feature(dev->protocol_features,
1521                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1522 
1523     if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))) {
1524         return 0;
1525     }
1526 
1527     msg.hdr.request = VHOST_USER_NET_SET_MTU;
1528     msg.payload.u64 = mtu;
1529     msg.hdr.size = sizeof(msg.payload.u64);
1530     msg.hdr.flags = VHOST_USER_VERSION;
1531     if (reply_supported) {
1532         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1533     }
1534 
1535     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1536         return -1;
1537     }
1538 
1539     /* If reply_ack supported, slave has to ack specified MTU is valid */
1540     if (reply_supported) {
1541         return process_message_reply(dev, &msg);
1542     }
1543 
1544     return 0;
1545 }
1546 
1547 static int vhost_user_send_device_iotlb_msg(struct vhost_dev *dev,
1548                                             struct vhost_iotlb_msg *imsg)
1549 {
1550     VhostUserMsg msg = {
1551         .hdr.request = VHOST_USER_IOTLB_MSG,
1552         .hdr.size = sizeof(msg.payload.iotlb),
1553         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1554         .payload.iotlb = *imsg,
1555     };
1556 
1557     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1558         return -EFAULT;
1559     }
1560 
1561     return process_message_reply(dev, &msg);
1562 }
1563 
1564 
1565 static void vhost_user_set_iotlb_callback(struct vhost_dev *dev, int enabled)
1566 {
1567     /* No-op as the receive channel is not dedicated to IOTLB messages. */
1568 }
1569 
1570 static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
1571                                  uint32_t config_len)
1572 {
1573     VhostUserMsg msg = {
1574         .hdr.request = VHOST_USER_GET_CONFIG,
1575         .hdr.flags = VHOST_USER_VERSION,
1576         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + config_len,
1577     };
1578 
1579     if (!virtio_has_feature(dev->protocol_features,
1580                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1581         return -1;
1582     }
1583 
1584     if (config_len > VHOST_USER_MAX_CONFIG_SIZE) {
1585         return -1;
1586     }
1587 
1588     msg.payload.config.offset = 0;
1589     msg.payload.config.size = config_len;
1590     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1591         return -1;
1592     }
1593 
1594     if (vhost_user_read(dev, &msg) < 0) {
1595         return -1;
1596     }
1597 
1598     if (msg.hdr.request != VHOST_USER_GET_CONFIG) {
1599         error_report("Received unexpected msg type. Expected %d received %d",
1600                      VHOST_USER_GET_CONFIG, msg.hdr.request);
1601         return -1;
1602     }
1603 
1604     if (msg.hdr.size != VHOST_USER_CONFIG_HDR_SIZE + config_len) {
1605         error_report("Received bad msg size.");
1606         return -1;
1607     }
1608 
1609     memcpy(config, msg.payload.config.region, config_len);
1610 
1611     return 0;
1612 }
1613 
1614 static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *data,
1615                                  uint32_t offset, uint32_t size, uint32_t flags)
1616 {
1617     uint8_t *p;
1618     bool reply_supported = virtio_has_feature(dev->protocol_features,
1619                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1620 
1621     VhostUserMsg msg = {
1622         .hdr.request = VHOST_USER_SET_CONFIG,
1623         .hdr.flags = VHOST_USER_VERSION,
1624         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + size,
1625     };
1626 
1627     if (!virtio_has_feature(dev->protocol_features,
1628                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1629         return -1;
1630     }
1631 
1632     if (reply_supported) {
1633         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1634     }
1635 
1636     if (size > VHOST_USER_MAX_CONFIG_SIZE) {
1637         return -1;
1638     }
1639 
1640     msg.payload.config.offset = offset,
1641     msg.payload.config.size = size,
1642     msg.payload.config.flags = flags,
1643     p = msg.payload.config.region;
1644     memcpy(p, data, size);
1645 
1646     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1647         return -1;
1648     }
1649 
1650     if (reply_supported) {
1651         return process_message_reply(dev, &msg);
1652     }
1653 
1654     return 0;
1655 }
1656 
1657 static int vhost_user_crypto_create_session(struct vhost_dev *dev,
1658                                             void *session_info,
1659                                             uint64_t *session_id)
1660 {
1661     bool crypto_session = virtio_has_feature(dev->protocol_features,
1662                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1663     CryptoDevBackendSymSessionInfo *sess_info = session_info;
1664     VhostUserMsg msg = {
1665         .hdr.request = VHOST_USER_CREATE_CRYPTO_SESSION,
1666         .hdr.flags = VHOST_USER_VERSION,
1667         .hdr.size = sizeof(msg.payload.session),
1668     };
1669 
1670     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1671 
1672     if (!crypto_session) {
1673         error_report("vhost-user trying to send unhandled ioctl");
1674         return -1;
1675     }
1676 
1677     memcpy(&msg.payload.session.session_setup_data, sess_info,
1678               sizeof(CryptoDevBackendSymSessionInfo));
1679     if (sess_info->key_len) {
1680         memcpy(&msg.payload.session.key, sess_info->cipher_key,
1681                sess_info->key_len);
1682     }
1683     if (sess_info->auth_key_len > 0) {
1684         memcpy(&msg.payload.session.auth_key, sess_info->auth_key,
1685                sess_info->auth_key_len);
1686     }
1687     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1688         error_report("vhost_user_write() return -1, create session failed");
1689         return -1;
1690     }
1691 
1692     if (vhost_user_read(dev, &msg) < 0) {
1693         error_report("vhost_user_read() return -1, create session failed");
1694         return -1;
1695     }
1696 
1697     if (msg.hdr.request != VHOST_USER_CREATE_CRYPTO_SESSION) {
1698         error_report("Received unexpected msg type. Expected %d received %d",
1699                      VHOST_USER_CREATE_CRYPTO_SESSION, msg.hdr.request);
1700         return -1;
1701     }
1702 
1703     if (msg.hdr.size != sizeof(msg.payload.session)) {
1704         error_report("Received bad msg size.");
1705         return -1;
1706     }
1707 
1708     if (msg.payload.session.session_id < 0) {
1709         error_report("Bad session id: %" PRId64 "",
1710                               msg.payload.session.session_id);
1711         return -1;
1712     }
1713     *session_id = msg.payload.session.session_id;
1714 
1715     return 0;
1716 }
1717 
1718 static int
1719 vhost_user_crypto_close_session(struct vhost_dev *dev, uint64_t session_id)
1720 {
1721     bool crypto_session = virtio_has_feature(dev->protocol_features,
1722                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1723     VhostUserMsg msg = {
1724         .hdr.request = VHOST_USER_CLOSE_CRYPTO_SESSION,
1725         .hdr.flags = VHOST_USER_VERSION,
1726         .hdr.size = sizeof(msg.payload.u64),
1727     };
1728     msg.payload.u64 = session_id;
1729 
1730     if (!crypto_session) {
1731         error_report("vhost-user trying to send unhandled ioctl");
1732         return -1;
1733     }
1734 
1735     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1736         error_report("vhost_user_write() return -1, close session failed");
1737         return -1;
1738     }
1739 
1740     return 0;
1741 }
1742 
1743 static bool vhost_user_mem_section_filter(struct vhost_dev *dev,
1744                                           MemoryRegionSection *section)
1745 {
1746     bool result;
1747 
1748     result = memory_region_get_fd(section->mr) >= 0;
1749 
1750     return result;
1751 }
1752 
1753 VhostUserState *vhost_user_init(void)
1754 {
1755     VhostUserState *user = g_new0(struct VhostUserState, 1);
1756 
1757     return user;
1758 }
1759 
1760 void vhost_user_cleanup(VhostUserState *user)
1761 {
1762     int i;
1763 
1764     for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1765         if (user->notifier[i].addr) {
1766             object_unparent(OBJECT(&user->notifier[i].mr));
1767             munmap(user->notifier[i].addr, qemu_real_host_page_size);
1768             user->notifier[i].addr = NULL;
1769         }
1770     }
1771 }
1772 
1773 const VhostOps user_ops = {
1774         .backend_type = VHOST_BACKEND_TYPE_USER,
1775         .vhost_backend_init = vhost_user_backend_init,
1776         .vhost_backend_cleanup = vhost_user_backend_cleanup,
1777         .vhost_backend_memslots_limit = vhost_user_memslots_limit,
1778         .vhost_set_log_base = vhost_user_set_log_base,
1779         .vhost_set_mem_table = vhost_user_set_mem_table,
1780         .vhost_set_vring_addr = vhost_user_set_vring_addr,
1781         .vhost_set_vring_endian = vhost_user_set_vring_endian,
1782         .vhost_set_vring_num = vhost_user_set_vring_num,
1783         .vhost_set_vring_base = vhost_user_set_vring_base,
1784         .vhost_get_vring_base = vhost_user_get_vring_base,
1785         .vhost_set_vring_kick = vhost_user_set_vring_kick,
1786         .vhost_set_vring_call = vhost_user_set_vring_call,
1787         .vhost_set_features = vhost_user_set_features,
1788         .vhost_get_features = vhost_user_get_features,
1789         .vhost_set_owner = vhost_user_set_owner,
1790         .vhost_reset_device = vhost_user_reset_device,
1791         .vhost_get_vq_index = vhost_user_get_vq_index,
1792         .vhost_set_vring_enable = vhost_user_set_vring_enable,
1793         .vhost_requires_shm_log = vhost_user_requires_shm_log,
1794         .vhost_migration_done = vhost_user_migration_done,
1795         .vhost_backend_can_merge = vhost_user_can_merge,
1796         .vhost_net_set_mtu = vhost_user_net_set_mtu,
1797         .vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
1798         .vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
1799         .vhost_get_config = vhost_user_get_config,
1800         .vhost_set_config = vhost_user_set_config,
1801         .vhost_crypto_create_session = vhost_user_crypto_create_session,
1802         .vhost_crypto_close_session = vhost_user_crypto_close_session,
1803         .vhost_backend_mem_section_filter = vhost_user_mem_section_filter,
1804 };
1805