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