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