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