1 /* 2 * Virtio Support 3 * 4 * Copyright IBM, Corp. 2007 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 */ 13 14 #ifndef QEMU_VIRTIO_H 15 #define QEMU_VIRTIO_H 16 17 #include "exec/memory.h" 18 #include "hw/qdev-core.h" 19 #include "net/net.h" 20 #include "migration/vmstate.h" 21 #include "qemu/event_notifier.h" 22 #include "standard-headers/linux/virtio_config.h" 23 #include "standard-headers/linux/virtio_ring.h" 24 #include "qom/object.h" 25 26 /* 27 * A guest should never accept this. It implies negotiation is broken 28 * between the driver frontend and the device. This bit is re-used for 29 * vhost-user to advertise VHOST_USER_F_PROTOCOL_FEATURES between QEMU 30 * and a vhost-user backend. 31 */ 32 #define VIRTIO_F_BAD_FEATURE 30 33 34 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \ 35 (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \ 36 (0x1ULL << VIRTIO_F_ANY_LAYOUT)) 37 38 #define LM_DISABLE 0x00 39 #define LM_ENABLE 0x01 40 41 struct VirtQueue; 42 43 static inline hwaddr vring_align(hwaddr addr, 44 unsigned long align) 45 { 46 return QEMU_ALIGN_UP(addr, align); 47 } 48 49 typedef struct VirtIOFeature { 50 uint64_t flags; 51 size_t end; 52 } VirtIOFeature; 53 54 typedef struct VirtIOConfigSizeParams { 55 size_t min_size; 56 size_t max_size; 57 const VirtIOFeature *feature_sizes; 58 } VirtIOConfigSizeParams; 59 60 size_t virtio_get_config_size(const VirtIOConfigSizeParams *params, 61 uint64_t host_features); 62 63 typedef struct VirtQueue VirtQueue; 64 65 #define VIRTQUEUE_MAX_SIZE 1024 66 67 typedef struct VirtQueueElement 68 { 69 unsigned int index; 70 unsigned int len; 71 unsigned int ndescs; 72 unsigned int out_num; 73 unsigned int in_num; 74 hwaddr *in_addr; 75 hwaddr *out_addr; 76 struct iovec *in_sg; 77 struct iovec *out_sg; 78 } VirtQueueElement; 79 80 #define VIRTIO_QUEUE_MAX 1024 81 82 #define VIRTIO_NO_VECTOR 0xffff 83 84 /* special index value used internally for config irqs */ 85 #define VIRTIO_CONFIG_IRQ_IDX -1 86 87 #define TYPE_VIRTIO_DEVICE "virtio-device" 88 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE) 89 90 typedef struct { 91 int virtio_bit; 92 const char *feature_desc; 93 } qmp_virtio_feature_map_t; 94 95 enum virtio_device_endian { 96 VIRTIO_DEVICE_ENDIAN_UNKNOWN, 97 VIRTIO_DEVICE_ENDIAN_LITTLE, 98 VIRTIO_DEVICE_ENDIAN_BIG, 99 }; 100 101 typedef struct BitmapMemoryRegionCaches { 102 struct rcu_head rcu; 103 MemoryRegionCache bitmap; 104 } BitmapMemoryRegionCaches; 105 106 /** 107 * struct VirtIODevice - common VirtIO structure 108 * @name: name of the device 109 * @status: VirtIO Device Status field 110 * 111 */ 112 struct VirtIODevice 113 { 114 DeviceState parent_obj; 115 const char *name; 116 uint8_t status; 117 uint8_t isr; 118 uint16_t queue_sel; 119 /** 120 * These fields represent a set of VirtIO features at various 121 * levels of the stack. @host_features indicates the complete 122 * feature set the VirtIO device can offer to the driver. 123 * @guest_features indicates which features the VirtIO driver has 124 * selected by writing to the feature register. Finally 125 * @backend_features represents everything supported by the 126 * backend (e.g. vhost) and could potentially be a subset of the 127 * total feature set offered by QEMU. 128 */ 129 uint64_t host_features; 130 uint64_t guest_features; 131 uint64_t backend_features; 132 133 size_t config_len; 134 void *config; 135 uint16_t config_vector; 136 uint32_t generation; 137 int nvectors; 138 VirtQueue *vq; 139 uint8_t lm_logging_ctrl; 140 uint32_t lm_base_addr_low; 141 uint32_t lm_base_addr_high; 142 uint32_t lm_end_addr_low; 143 uint32_t lm_end_addr_high; 144 145 BitmapMemoryRegionCaches *caches; 146 147 MemoryListener listener; 148 uint16_t device_id; 149 /* @vm_running: current VM running state via virtio_vmstate_change() */ 150 bool vm_running; 151 bool broken; /* device in invalid state, needs reset */ 152 bool use_disabled_flag; /* allow use of 'disable' flag when needed */ 153 bool disabled; /* device in temporarily disabled state */ 154 /** 155 * @use_started: true if the @started flag should be used to check the 156 * current state of the VirtIO device. Otherwise status bits 157 * should be checked for a current status of the device. 158 * @use_started is only set via QMP and defaults to true for all 159 * modern machines (since 4.1). 160 */ 161 bool use_started; 162 bool started; 163 bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */ 164 bool disable_legacy_check; 165 bool vhost_started; 166 VMChangeStateEntry *vmstate; 167 char *bus_name; 168 uint8_t device_endian; 169 /** 170 * @user_guest_notifier_mask: gate usage of ->guest_notifier_mask() callback. 171 * This is used to suppress the masking of guest updates for 172 * vhost-user devices which are asynchronous by design. 173 */ 174 bool use_guest_notifier_mask; 175 AddressSpace *dma_as; 176 QLIST_HEAD(, VirtQueue) *vector_queues; 177 QTAILQ_ENTRY(VirtIODevice) next; 178 /** 179 * @config_notifier: the event notifier that handles config events 180 */ 181 EventNotifier config_notifier; 182 bool device_iotlb_enabled; 183 }; 184 185 struct VirtioDeviceClass { 186 /*< private >*/ 187 DeviceClass parent; 188 /*< public >*/ 189 190 /* This is what a VirtioDevice must implement */ 191 DeviceRealize realize; 192 DeviceUnrealize unrealize; 193 uint64_t (*get_features)(VirtIODevice *vdev, 194 uint64_t requested_features, 195 Error **errp); 196 uint64_t (*bad_features)(VirtIODevice *vdev); 197 void (*set_features)(VirtIODevice *vdev, uint64_t val); 198 int (*validate_features)(VirtIODevice *vdev); 199 void (*get_config)(VirtIODevice *vdev, uint8_t *config); 200 void (*set_config)(VirtIODevice *vdev, const uint8_t *config); 201 void (*reset)(VirtIODevice *vdev); 202 void (*set_status)(VirtIODevice *vdev, uint8_t val); 203 /* Device must validate queue_index. */ 204 void (*queue_reset)(VirtIODevice *vdev, uint32_t queue_index); 205 /* Device must validate queue_index. */ 206 void (*queue_enable)(VirtIODevice *vdev, uint32_t queue_index); 207 /* For transitional devices, this is a bitmap of features 208 * that are only exposed on the legacy interface but not 209 * the modern one. 210 */ 211 uint64_t legacy_features; 212 /* Test and clear event pending status. 213 * Should be called after unmask to avoid losing events. 214 * If backend does not support masking, 215 * must check in frontend instead. 216 */ 217 bool (*guest_notifier_pending)(VirtIODevice *vdev, int n); 218 /* Mask/unmask events from this vq. Any events reported 219 * while masked will become pending. 220 * If backend does not support masking, 221 * must mask in frontend instead. 222 */ 223 void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask); 224 int (*start_ioeventfd)(VirtIODevice *vdev); 225 void (*stop_ioeventfd)(VirtIODevice *vdev); 226 /* Saving and loading of a device; trying to deprecate save/load 227 * use vmsd for new devices. 228 */ 229 void (*save)(VirtIODevice *vdev, QEMUFile *f); 230 int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); 231 /* Post load hook in vmsd is called early while device is processed, and 232 * when VirtIODevice isn't fully initialized. Devices should use this instead, 233 * unless they specifically want to verify the migration stream as it's 234 * processed, e.g. for bounds checking. 235 */ 236 int (*post_load)(VirtIODevice *vdev); 237 const VMStateDescription *vmsd; 238 bool (*primary_unplug_pending)(void *opaque); 239 struct vhost_dev *(*get_vhost)(VirtIODevice *vdev); 240 void (*toggle_device_iotlb)(VirtIODevice *vdev); 241 }; 242 243 void virtio_instance_init_common(Object *proxy_obj, void *data, 244 size_t vdev_size, const char *vdev_name); 245 246 /** 247 * virtio_init() - initialise the common VirtIODevice structure 248 * @vdev: pointer to VirtIODevice 249 * @device_id: the VirtIO device ID (see virtio_ids.h) 250 * @config_size: size of the config space 251 */ 252 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size); 253 254 void virtio_cleanup(VirtIODevice *vdev); 255 256 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3); 257 258 /* Set the child bus name. */ 259 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name); 260 261 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *); 262 263 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 264 VirtIOHandleOutput handle_output); 265 266 void virtio_del_queue(VirtIODevice *vdev, int n); 267 268 void virtio_delete_queue(VirtQueue *vq); 269 270 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 271 unsigned int len); 272 void virtqueue_flush(VirtQueue *vq, unsigned int count); 273 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 274 unsigned int len); 275 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 276 unsigned int len); 277 bool virtqueue_rewind(VirtQueue *vq, unsigned int num); 278 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 279 unsigned int len, unsigned int idx); 280 281 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem); 282 void *virtqueue_pop(VirtQueue *vq, size_t sz); 283 unsigned int virtqueue_drop_all(VirtQueue *vq); 284 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz); 285 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 286 VirtQueueElement *elem); 287 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 288 unsigned int out_bytes); 289 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 290 unsigned int *out_bytes, 291 unsigned max_in_bytes, unsigned max_out_bytes); 292 293 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq); 294 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq); 295 296 int virtio_save(VirtIODevice *vdev, QEMUFile *f); 297 298 extern const VMStateInfo virtio_vmstate_info; 299 300 #define VMSTATE_VIRTIO_DEVICE \ 301 { \ 302 .name = "virtio", \ 303 .info = &virtio_vmstate_info, \ 304 .flags = VMS_SINGLE, \ 305 } 306 307 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id); 308 309 /** 310 * virtio_notify_config() - signal a change to device config 311 * @vdev: the virtio device 312 * 313 * Assuming the virtio device is up (VIRTIO_CONFIG_S_DRIVER_OK) this 314 * will trigger a guest interrupt and update the config version. 315 */ 316 void virtio_notify_config(VirtIODevice *vdev); 317 318 bool virtio_queue_get_notification(VirtQueue *vq); 319 void virtio_queue_set_notification(VirtQueue *vq, int enable); 320 321 int virtio_queue_ready(VirtQueue *vq); 322 323 int virtio_queue_empty(VirtQueue *vq); 324 325 /* Host binding interface. */ 326 327 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr); 328 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr); 329 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr); 330 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data); 331 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data); 332 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data); 333 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr); 334 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr); 335 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr); 336 void virtio_config_modern_writeb(VirtIODevice *vdev, 337 uint32_t addr, uint32_t data); 338 void virtio_config_modern_writew(VirtIODevice *vdev, 339 uint32_t addr, uint32_t data); 340 void virtio_config_modern_writel(VirtIODevice *vdev, 341 uint32_t addr, uint32_t data); 342 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr); 343 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n); 344 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num); 345 int virtio_queue_get_num(VirtIODevice *vdev, int n); 346 int virtio_queue_get_max_num(VirtIODevice *vdev, int n); 347 int virtio_get_num_queues(VirtIODevice *vdev); 348 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 349 hwaddr avail, hwaddr used); 350 void virtio_queue_update_rings(VirtIODevice *vdev, int n); 351 void virtio_init_region_cache(VirtIODevice *vdev, int n); 352 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align); 353 void virtio_queue_notify(VirtIODevice *vdev, int n); 354 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); 355 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector); 356 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 357 MemoryRegion *mr, bool assign); 358 int virtio_set_status(VirtIODevice *vdev, uint8_t val); 359 void virtio_reset(void *opaque); 360 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index); 361 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index); 362 void virtio_update_irq(VirtIODevice *vdev); 363 int virtio_set_features(VirtIODevice *vdev, uint64_t val); 364 365 /* Base devices. */ 366 typedef struct VirtIOBlkConf VirtIOBlkConf; 367 struct virtio_net_conf; 368 typedef struct virtio_serial_conf virtio_serial_conf; 369 typedef struct virtio_input_conf virtio_input_conf; 370 typedef struct VirtIOSCSIConf VirtIOSCSIConf; 371 typedef struct VirtIORNGConf VirtIORNGConf; 372 373 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \ 374 DEFINE_PROP_BIT64("indirect_desc", _state, _field, \ 375 VIRTIO_RING_F_INDIRECT_DESC, true), \ 376 DEFINE_PROP_BIT64("event_idx", _state, _field, \ 377 VIRTIO_RING_F_EVENT_IDX, true), \ 378 DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \ 379 VIRTIO_F_NOTIFY_ON_EMPTY, true), \ 380 DEFINE_PROP_BIT64("any_layout", _state, _field, \ 381 VIRTIO_F_ANY_LAYOUT, true), \ 382 DEFINE_PROP_BIT64("iommu_platform", _state, _field, \ 383 VIRTIO_F_IOMMU_PLATFORM, false), \ 384 DEFINE_PROP_BIT64("packed", _state, _field, \ 385 VIRTIO_F_RING_PACKED, false), \ 386 DEFINE_PROP_BIT64("queue_reset", _state, _field, \ 387 VIRTIO_F_RING_RESET, true) 388 389 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n); 390 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n); 391 bool virtio_queue_enabled(VirtIODevice *vdev, int n); 392 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n); 393 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n); 394 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n); 395 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n); 396 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n); 397 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n); 398 unsigned int virtio_queue_get_vring_states(VirtIODevice *vdev, int n); 399 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 400 unsigned int idx); 401 void virtio_queue_set_vring_states(VirtIODevice *vdev, int n, 402 unsigned int idx); 403 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n); 404 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n); 405 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n); 406 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n); 407 uint16_t virtio_get_queue_index(VirtQueue *vq); 408 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq); 409 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 410 bool with_irqfd); 411 int virtio_device_start_ioeventfd(VirtIODevice *vdev); 412 int virtio_device_grab_ioeventfd(VirtIODevice *vdev); 413 void virtio_device_release_ioeventfd(VirtIODevice *vdev); 414 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev); 415 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); 416 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled); 417 void virtio_queue_host_notifier_read(EventNotifier *n); 418 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx); 419 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx); 420 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx); 421 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector); 422 VirtQueue *virtio_vector_next_queue(VirtQueue *vq); 423 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev); 424 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev, 425 bool assign, bool with_irqfd); 426 427 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit) 428 { 429 assert(fbit < 64); 430 *features |= (1ULL << fbit); 431 } 432 433 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit) 434 { 435 assert(fbit < 64); 436 *features &= ~(1ULL << fbit); 437 } 438 439 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit) 440 { 441 assert(fbit < 64); 442 return !!(features & (1ULL << fbit)); 443 } 444 445 static inline bool virtio_vdev_has_feature(const VirtIODevice *vdev, 446 unsigned int fbit) 447 { 448 return virtio_has_feature(vdev->guest_features, fbit); 449 } 450 451 static inline bool virtio_host_has_feature(VirtIODevice *vdev, 452 unsigned int fbit) 453 { 454 return virtio_has_feature(vdev->host_features, fbit); 455 } 456 457 static inline bool virtio_is_big_endian(VirtIODevice *vdev) 458 { 459 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 460 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 461 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 462 } 463 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 464 return false; 465 } 466 467 /** 468 * virtio_device_started() - check if device started 469 * @vdev - the VirtIO device 470 * @status - the devices status bits 471 * 472 * Check if the device is started. For most modern machines this is 473 * tracked via the @vdev->started field (to support migration), 474 * otherwise we check for the final negotiated status bit that 475 * indicates everything is ready. 476 */ 477 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status) 478 { 479 if (vdev->use_started) { 480 return vdev->started; 481 } 482 483 return status & VIRTIO_CONFIG_S_DRIVER_OK; 484 } 485 486 /** 487 * virtio_device_should_start() - check if device startable 488 * @vdev - the VirtIO device 489 * @status - the devices status bits 490 * 491 * This is similar to virtio_device_started() but also encapsulates a 492 * check on the VM status which would prevent a device starting 493 * anyway. 494 */ 495 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status) 496 { 497 if (!vdev->vm_running) { 498 return false; 499 } 500 501 return virtio_device_started(vdev, status); 502 } 503 504 static inline void virtio_set_started(VirtIODevice *vdev, bool started) 505 { 506 if (started) { 507 vdev->start_on_kick = false; 508 } 509 510 if (vdev->use_started) { 511 vdev->started = started; 512 } 513 } 514 515 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable) 516 { 517 if (vdev->use_disabled_flag) { 518 vdev->disabled = disable; 519 } 520 } 521 522 static inline bool virtio_device_disabled(VirtIODevice *vdev) 523 { 524 return unlikely(vdev->disabled || vdev->broken); 525 } 526 527 bool virtio_legacy_allowed(VirtIODevice *vdev); 528 bool virtio_legacy_check_disabled(VirtIODevice *vdev); 529 530 #endif 531