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