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) < 0 ? -errno : 0;
  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 < INT_MAX && val > 0) {
  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 static int vhost_kernel_vsock_set_guest_cid(struct vhost_dev *dev,
 207                                             uint64_t guest_cid)
 208 {
 209     return vhost_kernel_call(dev, VHOST_VSOCK_SET_GUEST_CID, &guest_cid);
 210 }
 211
 212 static int vhost_kernel_vsock_set_running(struct vhost_dev *dev, int start)
 213 {
 214     return vhost_kernel_call(dev, VHOST_VSOCK_SET_RUNNING, &start);
 215 }
 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 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         .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
 321         .vhost_vsock_set_running = vhost_kernel_vsock_set_running,
 322         .vhost_set_iotlb_callback = vhost_kernel_set_iotlb_callback,
 323         .vhost_send_device_iotlb_msg = vhost_kernel_send_device_iotlb_msg,
 324 };
 325 #endif
 326
 327 int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
 328                                              uint64_t iova, uint64_t uaddr,
 329                                              uint64_t len,
 330                                              IOMMUAccessFlags perm)
 331 {
 332     struct vhost_iotlb_msg imsg;
 333
 334     imsg.iova =  iova;
 335     imsg.uaddr = uaddr;
 336     imsg.size = len;
 337     imsg.type = VHOST_IOTLB_UPDATE;
 338
 339     switch (perm) {
 340     case IOMMU_RO:
 341         imsg.perm = VHOST_ACCESS_RO;
 342         break;
 343     case IOMMU_WO:
 344         imsg.perm = VHOST_ACCESS_WO;
 345         break;
 346     case IOMMU_RW:
 347         imsg.perm = VHOST_ACCESS_RW;
 348         break;
 349     default:
 350         return -EINVAL;
 351     }
 352
 353     if (dev->vhost_ops && dev->vhost_ops->vhost_send_device_iotlb_msg)
 354         return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
 355
 356     return -ENODEV;
 357 }
 358
 359 int vhost_backend_invalidate_device_iotlb(struct vhost_dev *dev,
 360                                                  uint64_t iova, uint64_t len)
 361 {
 362     struct vhost_iotlb_msg imsg;
 363
 364     imsg.iova = iova;
 365     imsg.size = len;
 366     imsg.type = VHOST_IOTLB_INVALIDATE;
 367
 368     if (dev->vhost_ops && dev->vhost_ops->vhost_send_device_iotlb_msg)
 369         return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
 370
 371     return -ENODEV;
 372 }
 373
 374 int vhost_backend_handle_iotlb_msg(struct vhost_dev *dev,
 375                                           struct vhost_iotlb_msg *imsg)
 376 {
 377     int ret = 0;
 378
 379     if (unlikely(!dev->vdev)) {
 380         error_report("Unexpected IOTLB message when virtio device is stopped");
 381         return -EINVAL;
 382     }
 383
 384     switch (imsg->type) {
 385     case VHOST_IOTLB_MISS:
 386         ret = vhost_device_iotlb_miss(dev, imsg->iova,
 387                                       imsg->perm != VHOST_ACCESS_RO);
 388         break;
 389     case VHOST_IOTLB_ACCESS_FAIL:
 390         /* FIXME: report device iotlb error */
 391         error_report("Access failure IOTLB message type not supported");
 392         ret = -ENOTSUP;
 393         break;
 394     case VHOST_IOTLB_UPDATE:
 395     case VHOST_IOTLB_INVALIDATE:
 396     default:
 397         error_report("Unexpected IOTLB message type");
 398         ret = -EINVAL;
 399         break;
 400     }
 401
 402     return ret;
 403 }