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