hw/virtio/vhost-backend.c

   1 /*
   2  * vhost-backend
   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 "hw/virtio/vhost.h"
  13 #include "hw/virtio/vhost-backend.h"
  14 #include "qemu/error-report.h"
  15 #include "qemu/main-loop.h"
  16 #include "standard-headers/linux/vhost_types.h"
  17
  18 #include "hw/virtio/vhost-vdpa.h"
  19 #ifdef CONFIG_VHOST_KERNEL
  20 #include <linux/vhost.h>
  21 #include <sys/ioctl.h>
  22
  23 static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
  24                              void *arg)
  25 {
  26     int fd = (uintptr_t) dev->opaque;
  27
  28     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  29
  30     return ioctl(fd, request, arg);
  31 }
  32
  33 static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
  34 {
  35     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  36
  37     dev->opaque = opaque;
  38
  39     return 0;
  40 }
  41
  42 static int vhost_kernel_cleanup(struct vhost_dev *dev)
  43 {
  44     int fd = (uintptr_t) dev->opaque;
  45
  46     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  47
  48     return close(fd);
  49 }
  50
  51 static int vhost_kernel_memslots_limit(struct vhost_dev *dev)
  52 {
  53     int limit = 64;
  54     char *s;
  55
  56     if (g_file_get_contents("/sys/module/vhost/parameters/max_mem_regions",
  57                             &s, NULL, NULL)) {
  58         uint64_t val = g_ascii_strtoull(s, NULL, 10);
  59         if (!((val == G_MAXUINT64 || !val) && errno)) {
  60             g_free(s);
  61             return val;
  62         }
  63         error_report("ignoring invalid max_mem_regions value in vhost module:"
  64                      " %s", s);
  65     }
  66     g_free(s);
  67     return limit;
  68 }
  69
  70 static int vhost_kernel_net_set_backend(struct vhost_dev *dev,
  71                                         struct vhost_vring_file *file)
  72 {
  73     return vhost_kernel_call(dev, VHOST_NET_SET_BACKEND, file);
  74 }
  75
  76 static int vhost_kernel_scsi_set_endpoint(struct vhost_dev *dev,
  77                                           struct vhost_scsi_target *target)
  78 {
  79     return vhost_kernel_call(dev, VHOST_SCSI_SET_ENDPOINT, target);
  80 }
  81
  82 static int vhost_kernel_scsi_clear_endpoint(struct vhost_dev *dev,
  83                                             struct vhost_scsi_target *target)
  84 {
  85     return vhost_kernel_call(dev, VHOST_SCSI_CLEAR_ENDPOINT, target);
  86 }
  87
  88 static int vhost_kernel_scsi_get_abi_version(struct vhost_dev *dev, int *version)
  89 {
  90     return vhost_kernel_call(dev, VHOST_SCSI_GET_ABI_VERSION, version);
  91 }
  92
  93 static int vhost_kernel_set_log_base(struct vhost_dev *dev, uint64_t base,
  94                                      struct vhost_log *log)
  95 {
  96     return vhost_kernel_call(dev, VHOST_SET_LOG_BASE, &base);
  97 }
  98
  99 static int vhost_kernel_set_mem_table(struct vhost_dev *dev,
 100                                       struct vhost_memory *mem)
 101 {
 102     return vhost_kernel_call(dev, VHOST_SET_MEM_TABLE, mem);
 103 }
 104
 105 static int vhost_kernel_set_vring_addr(struct vhost_dev *dev,
 106                                        struct vhost_vring_addr *addr)
 107 {
 108     return vhost_kernel_call(dev, VHOST_SET_VRING_ADDR, addr);
 109 }
 110
 111 static int vhost_kernel_set_vring_endian(struct vhost_dev *dev,
 112                                          struct vhost_vring_state *ring)
 113 {
 114     return vhost_kernel_call(dev, VHOST_SET_VRING_ENDIAN, ring);
 115 }
 116
 117 static int vhost_kernel_set_vring_num(struct vhost_dev *dev,
 118                                       struct vhost_vring_state *ring)
 119 {
 120     return vhost_kernel_call(dev, VHOST_SET_VRING_NUM, ring);
 121 }
 122
 123 static int vhost_kernel_set_vring_base(struct vhost_dev *dev,
 124                                        struct vhost_vring_state *ring)
 125 {
 126     return vhost_kernel_call(dev, VHOST_SET_VRING_BASE, ring);
 127 }
 128
 129 static int vhost_kernel_get_vring_base(struct vhost_dev *dev,
 130                                        struct vhost_vring_state *ring)
 131 {
 132     return vhost_kernel_call(dev, VHOST_GET_VRING_BASE, ring);
 133 }
 134
 135 static int vhost_kernel_set_vring_kick(struct vhost_dev *dev,
 136                                        struct vhost_vring_file *file)
 137 {
 138     return vhost_kernel_call(dev, VHOST_SET_VRING_KICK, file);
 139 }
 140
 141 static int vhost_kernel_set_vring_call(struct vhost_dev *dev,
 142                                        struct vhost_vring_file *file)
 143 {
 144     return vhost_kernel_call(dev, VHOST_SET_VRING_CALL, file);
 145 }
 146
 147 static int vhost_kernel_set_vring_busyloop_timeout(struct vhost_dev *dev,
 148                                                    struct vhost_vring_state *s)
 149 {
 150     return vhost_kernel_call(dev, VHOST_SET_VRING_BUSYLOOP_TIMEOUT, s);
 151 }
 152
 153 static int vhost_kernel_set_features(struct vhost_dev *dev,
 154                                      uint64_t features)
 155 {
 156     return vhost_kernel_call(dev, VHOST_SET_FEATURES, &features);
 157 }
 158
 159 static int vhost_kernel_set_backend_cap(struct vhost_dev *dev)
 160 {
 161     uint64_t features;
 162     uint64_t f = 0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2;
 163     int r;
 164
 165     if (vhost_kernel_call(dev, VHOST_GET_BACKEND_FEATURES, &features)) {
 166         return 0;
 167     }
 168
 169     features &= f;
 170     r = vhost_kernel_call(dev, VHOST_SET_BACKEND_FEATURES,
 171                               &features);
 172     if (r) {
 173         return 0;
 174     }
 175
 176     dev->backend_cap = features;
 177
 178     return 0;
 179 }
 180
 181 static int vhost_kernel_get_features(struct vhost_dev *dev,
 182                                      uint64_t *features)
 183 {
 184     return vhost_kernel_call(dev, VHOST_GET_FEATURES, features);
 185 }
 186
 187 static int vhost_kernel_set_owner(struct vhost_dev *dev)
 188 {
 189     return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
 190 }
 191
 192 static int vhost_kernel_reset_device(struct vhost_dev *dev)
 193 {
 194     return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
 195 }
 196
 197 static int vhost_kernel_get_vq_index(struct vhost_dev *dev, int idx)
 198 {
 199     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
 200
 201     return idx - dev->vq_index;
 202 }
 203
 204 #ifdef CONFIG_VHOST_VSOCK
 205 static int vhost_kernel_vsock_set_guest_cid(struct vhost_dev *dev,
 206                                             uint64_t guest_cid)
 207 {
 208     return vhost_kernel_call(dev, VHOST_VSOCK_SET_GUEST_CID, &guest_cid);
 209 }
 210
 211 static int vhost_kernel_vsock_set_running(struct vhost_dev *dev, int start)
 212 {
 213     return vhost_kernel_call(dev, VHOST_VSOCK_SET_RUNNING, &start);
 214 }
 215 #endif /* CONFIG_VHOST_VSOCK */
 216
 217 static void vhost_kernel_iotlb_read(void *opaque)
 218 {
 219     struct vhost_dev *dev = opaque;
 220     ssize_t len;
 221
 222     if (dev->backend_cap &
 223         (0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)) {
 224         struct vhost_msg_v2 msg;
 225
 226         while ((len = read((uintptr_t)dev->opaque, &msg, sizeof msg)) > 0) {
 227             if (len < sizeof msg) {
 228                 error_report("Wrong vhost message len: %d", (int)len);
 229                 break;
 230             }
 231             if (msg.type != VHOST_IOTLB_MSG_V2) {
 232                 error_report("Unknown vhost iotlb message type");
 233                 break;
 234             }
 235
 236             vhost_backend_handle_iotlb_msg(dev, &msg.iotlb);
 237         }
 238     } else {
 239         struct vhost_msg msg;
 240
 241         while ((len = read((uintptr_t)dev->opaque, &msg, sizeof msg)) > 0) {
 242             if (len < sizeof msg) {
 243                 error_report("Wrong vhost message len: %d", (int)len);
 244                 break;
 245             }
 246             if (msg.type != VHOST_IOTLB_MSG) {
 247                 error_report("Unknown vhost iotlb message type");
 248                 break;
 249             }
 250
 251             vhost_backend_handle_iotlb_msg(dev, &msg.iotlb);
 252         }
 253     }
 254 }
 255
 256 static int vhost_kernel_send_device_iotlb_msg(struct vhost_dev *dev,
 257                                               struct vhost_iotlb_msg *imsg)
 258 {
 259     if (dev->backend_cap & (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)) {
 260         struct vhost_msg_v2 msg = {};
 261
 262         msg.type = VHOST_IOTLB_MSG_V2;
 263         msg.iotlb = *imsg;
 264
 265         if (write((uintptr_t)dev->opaque, &msg, sizeof msg) != sizeof msg) {
 266             error_report("Fail to update device iotlb");
 267             return -EFAULT;
 268         }
 269     } else {
 270         struct vhost_msg msg = {};
 271
 272         msg.type = VHOST_IOTLB_MSG;
 273         msg.iotlb = *imsg;
 274
 275         if (write((uintptr_t)dev->opaque, &msg, sizeof msg) != sizeof msg) {
 276             error_report("Fail to update device iotlb");
 277             return -EFAULT;
 278         }
 279     }
 280
 281     return 0;
 282 }
 283
 284 static void vhost_kernel_set_iotlb_callback(struct vhost_dev *dev,
 285                                            int enabled)
 286 {
 287     if (enabled)
 288         qemu_set_fd_handler((uintptr_t)dev->opaque,
 289                             vhost_kernel_iotlb_read, NULL, dev);
 290     else
 291         qemu_set_fd_handler((uintptr_t)dev->opaque, NULL, NULL, NULL);
 292 }
 293
 294 static const VhostOps kernel_ops = {
 295         .backend_type = VHOST_BACKEND_TYPE_KERNEL,
 296         .vhost_backend_init = vhost_kernel_init,
 297         .vhost_backend_cleanup = vhost_kernel_cleanup,
 298         .vhost_backend_memslots_limit = vhost_kernel_memslots_limit,
 299         .vhost_net_set_backend = vhost_kernel_net_set_backend,
 300         .vhost_scsi_set_endpoint = vhost_kernel_scsi_set_endpoint,
 301         .vhost_scsi_clear_endpoint = vhost_kernel_scsi_clear_endpoint,
 302         .vhost_scsi_get_abi_version = vhost_kernel_scsi_get_abi_version,
 303         .vhost_set_log_base = vhost_kernel_set_log_base,
 304         .vhost_set_mem_table = vhost_kernel_set_mem_table,
 305         .vhost_set_vring_addr = vhost_kernel_set_vring_addr,
 306         .vhost_set_vring_endian = vhost_kernel_set_vring_endian,
 307         .vhost_set_vring_num = vhost_kernel_set_vring_num,
 308         .vhost_set_vring_base = vhost_kernel_set_vring_base,
 309         .vhost_get_vring_base = vhost_kernel_get_vring_base,
 310         .vhost_set_vring_kick = vhost_kernel_set_vring_kick,
 311         .vhost_set_vring_call = vhost_kernel_set_vring_call,
 312         .vhost_set_vring_busyloop_timeout =
 313                                 vhost_kernel_set_vring_busyloop_timeout,
 314         .vhost_set_features = vhost_kernel_set_features,
 315         .vhost_get_features = vhost_kernel_get_features,
 316         .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
 317         .vhost_set_owner = vhost_kernel_set_owner,
 318         .vhost_reset_device = vhost_kernel_reset_device,
 319         .vhost_get_vq_index = vhost_kernel_get_vq_index,
 320 #ifdef CONFIG_VHOST_VSOCK
 321         .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
 322         .vhost_vsock_set_running = vhost_kernel_vsock_set_running,
 323 #endif /* CONFIG_VHOST_VSOCK */
 324         .vhost_set_iotlb_callback = vhost_kernel_set_iotlb_callback,
 325         .vhost_send_device_iotlb_msg = vhost_kernel_send_device_iotlb_msg,
 326 };
 327 #endif
 328
 329 int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
 330 {
 331     int r = 0;
 332
 333     switch (backend_type) {
 334 #ifdef CONFIG_VHOST_KERNEL
 335     case VHOST_BACKEND_TYPE_KERNEL:
 336         dev->vhost_ops = &kernel_ops;
 337         break;
 338 #endif
 339 #ifdef CONFIG_VHOST_USER
 340     case VHOST_BACKEND_TYPE_USER:
 341         dev->vhost_ops = &user_ops;
 342         break;
 343 #endif
 344 #ifdef CONFIG_VHOST_VDPA
 345     case VHOST_BACKEND_TYPE_VDPA:
 346         dev->vhost_ops = &vdpa_ops;
 347         break;
 348 #endif
 349     default:
 350         error_report("Unknown vhost backend type");
 351         r = -1;
 352     }
 353
 354     return r;
 355 }
 356
 357 int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
 358                                              uint64_t iova, uint64_t uaddr,
 359                                              uint64_t len,
 360                                              IOMMUAccessFlags perm)
 361 {
 362     struct vhost_iotlb_msg imsg;
 363
 364     imsg.iova =  iova;
 365     imsg.uaddr = uaddr;
 366     imsg.size = len;
 367     imsg.type = VHOST_IOTLB_UPDATE;
 368
 369     switch (perm) {
 370     case IOMMU_RO:
 371         imsg.perm = VHOST_ACCESS_RO;
 372         break;
 373     case IOMMU_WO:
 374         imsg.perm = VHOST_ACCESS_WO;
 375         break;
 376     case IOMMU_RW:
 377         imsg.perm = VHOST_ACCESS_RW;
 378         break;
 379     default:
 380         return -EINVAL;
 381     }
 382
 383     if (dev->vhost_ops && dev->vhost_ops->vhost_send_device_iotlb_msg)
 384         return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
 385
 386     return -ENODEV;
 387 }
 388
 389 int vhost_backend_invalidate_device_iotlb(struct vhost_dev *dev,
 390                                                  uint64_t iova, uint64_t len)
 391 {
 392     struct vhost_iotlb_msg imsg;
 393
 394     imsg.iova = iova;
 395     imsg.size = len;
 396     imsg.type = VHOST_IOTLB_INVALIDATE;
 397
 398     if (dev->vhost_ops && dev->vhost_ops->vhost_send_device_iotlb_msg)
 399         return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
 400
 401     return -ENODEV;
 402 }
 403
 404 int vhost_backend_handle_iotlb_msg(struct vhost_dev *dev,
 405                                           struct vhost_iotlb_msg *imsg)
 406 {
 407     int ret = 0;
 408
 409     if (unlikely(!dev->vdev)) {
 410         error_report("Unexpected IOTLB message when virtio device is stopped");
 411         return -EINVAL;
 412     }
 413
 414     switch (imsg->type) {
 415     case VHOST_IOTLB_MISS:
 416         ret = vhost_device_iotlb_miss(dev, imsg->iova,
 417                                       imsg->perm != VHOST_ACCESS_RO);
 418         break;
 419     case VHOST_IOTLB_ACCESS_FAIL:
 420         /* FIXME: report device iotlb error */
 421         error_report("Access failure IOTLB message type not supported");
 422         ret = -ENOTSUP;
 423         break;
 424     case VHOST_IOTLB_UPDATE:
 425     case VHOST_IOTLB_INVALIDATE:
 426     default:
 427         error_report("Unexpected IOTLB message type");
 428         ret = -EINVAL;
 429         break;
 430     }
 431
 432     return ret;
 433 }