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