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 bool use_guest_notifier_mask; 154 AddressSpace *dma_as; 155 QLIST_HEAD(, VirtQueue) *vector_queues; 156 QTAILQ_ENTRY(VirtIODevice) next; 157 EventNotifier config_notifier; 158 }; 159 160 struct VirtioDeviceClass { 161 /*< private >*/ 162 DeviceClass parent; 163 /*< public >*/ 164 165 /* This is what a VirtioDevice must implement */ 166 DeviceRealize realize; 167 DeviceUnrealize unrealize; 168 uint64_t (*get_features)(VirtIODevice *vdev, 169 uint64_t requested_features, 170 Error **errp); 171 uint64_t (*bad_features)(VirtIODevice *vdev); 172 void (*set_features)(VirtIODevice *vdev, uint64_t val); 173 int (*validate_features)(VirtIODevice *vdev); 174 void (*get_config)(VirtIODevice *vdev, uint8_t *config); 175 void (*set_config)(VirtIODevice *vdev, const uint8_t *config); 176 void (*reset)(VirtIODevice *vdev); 177 void (*set_status)(VirtIODevice *vdev, uint8_t val); 178 /* Device must validate queue_index. */ 179 void (*queue_reset)(VirtIODevice *vdev, uint32_t queue_index); 180 /* Device must validate queue_index. */ 181 void (*queue_enable)(VirtIODevice *vdev, uint32_t queue_index); 182 /* For transitional devices, this is a bitmap of features 183 * that are only exposed on the legacy interface but not 184 * the modern one. 185 */ 186 uint64_t legacy_features; 187 /* Test and clear event pending status. 188 * Should be called after unmask to avoid losing events. 189 * If backend does not support masking, 190 * must check in frontend instead. 191 */ 192 bool (*guest_notifier_pending)(VirtIODevice *vdev, int n); 193 /* Mask/unmask events from this vq. Any events reported 194 * while masked will become pending. 195 * If backend does not support masking, 196 * must mask in frontend instead. 197 */ 198 void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask); 199 int (*start_ioeventfd)(VirtIODevice *vdev); 200 void (*stop_ioeventfd)(VirtIODevice *vdev); 201 /* Saving and loading of a device; trying to deprecate save/load 202 * use vmsd for new devices. 203 */ 204 void (*save)(VirtIODevice *vdev, QEMUFile *f); 205 int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); 206 /* Post load hook in vmsd is called early while device is processed, and 207 * when VirtIODevice isn't fully initialized. Devices should use this instead, 208 * unless they specifically want to verify the migration stream as it's 209 * processed, e.g. for bounds checking. 210 */ 211 int (*post_load)(VirtIODevice *vdev); 212 const VMStateDescription *vmsd; 213 bool (*primary_unplug_pending)(void *opaque); 214 struct vhost_dev *(*get_vhost)(VirtIODevice *vdev); 215 }; 216 217 void virtio_instance_init_common(Object *proxy_obj, void *data, 218 size_t vdev_size, const char *vdev_name); 219 220 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size); 221 222 void virtio_cleanup(VirtIODevice *vdev); 223 224 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3); 225 226 /* Set the child bus name. */ 227 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name); 228 229 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *); 230 231 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 232 VirtIOHandleOutput handle_output); 233 234 void virtio_del_queue(VirtIODevice *vdev, int n); 235 236 void virtio_delete_queue(VirtQueue *vq); 237 238 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 239 unsigned int len); 240 void virtqueue_flush(VirtQueue *vq, unsigned int count); 241 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 242 unsigned int len); 243 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 244 unsigned int len); 245 bool virtqueue_rewind(VirtQueue *vq, unsigned int num); 246 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 247 unsigned int len, unsigned int idx); 248 249 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem); 250 void *virtqueue_pop(VirtQueue *vq, size_t sz); 251 unsigned int virtqueue_drop_all(VirtQueue *vq); 252 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz); 253 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 254 VirtQueueElement *elem); 255 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 256 unsigned int out_bytes); 257 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 258 unsigned int *out_bytes, 259 unsigned max_in_bytes, unsigned max_out_bytes); 260 261 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq); 262 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq); 263 264 int virtio_save(VirtIODevice *vdev, QEMUFile *f); 265 266 extern const VMStateInfo virtio_vmstate_info; 267 268 #define VMSTATE_VIRTIO_DEVICE \ 269 { \ 270 .name = "virtio", \ 271 .info = &virtio_vmstate_info, \ 272 .flags = VMS_SINGLE, \ 273 } 274 275 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id); 276 277 void virtio_notify_config(VirtIODevice *vdev); 278 279 bool virtio_queue_get_notification(VirtQueue *vq); 280 void virtio_queue_set_notification(VirtQueue *vq, int enable); 281 282 int virtio_queue_ready(VirtQueue *vq); 283 284 int virtio_queue_empty(VirtQueue *vq); 285 286 /* Host binding interface. */ 287 288 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr); 289 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr); 290 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr); 291 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data); 292 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data); 293 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data); 294 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr); 295 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr); 296 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr); 297 void virtio_config_modern_writeb(VirtIODevice *vdev, 298 uint32_t addr, uint32_t data); 299 void virtio_config_modern_writew(VirtIODevice *vdev, 300 uint32_t addr, uint32_t data); 301 void virtio_config_modern_writel(VirtIODevice *vdev, 302 uint32_t addr, uint32_t data); 303 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr); 304 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n); 305 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num); 306 int virtio_queue_get_num(VirtIODevice *vdev, int n); 307 int virtio_queue_get_max_num(VirtIODevice *vdev, int n); 308 int virtio_get_num_queues(VirtIODevice *vdev); 309 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 310 hwaddr avail, hwaddr used); 311 void virtio_queue_update_rings(VirtIODevice *vdev, int n); 312 void virtio_init_region_cache(VirtIODevice *vdev, int n); 313 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align); 314 void virtio_queue_notify(VirtIODevice *vdev, int n); 315 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); 316 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector); 317 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 318 MemoryRegion *mr, bool assign); 319 int virtio_set_status(VirtIODevice *vdev, uint8_t val); 320 void virtio_reset(void *opaque); 321 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index); 322 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index); 323 void virtio_update_irq(VirtIODevice *vdev); 324 int virtio_set_features(VirtIODevice *vdev, uint64_t val); 325 326 /* Base devices. */ 327 typedef struct VirtIOBlkConf VirtIOBlkConf; 328 struct virtio_net_conf; 329 typedef struct virtio_serial_conf virtio_serial_conf; 330 typedef struct virtio_input_conf virtio_input_conf; 331 typedef struct VirtIOSCSIConf VirtIOSCSIConf; 332 typedef struct VirtIORNGConf VirtIORNGConf; 333 334 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \ 335 DEFINE_PROP_BIT64("indirect_desc", _state, _field, \ 336 VIRTIO_RING_F_INDIRECT_DESC, true), \ 337 DEFINE_PROP_BIT64("event_idx", _state, _field, \ 338 VIRTIO_RING_F_EVENT_IDX, true), \ 339 DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \ 340 VIRTIO_F_NOTIFY_ON_EMPTY, true), \ 341 DEFINE_PROP_BIT64("any_layout", _state, _field, \ 342 VIRTIO_F_ANY_LAYOUT, true), \ 343 DEFINE_PROP_BIT64("iommu_platform", _state, _field, \ 344 VIRTIO_F_IOMMU_PLATFORM, false), \ 345 DEFINE_PROP_BIT64("packed", _state, _field, \ 346 VIRTIO_F_RING_PACKED, false), \ 347 DEFINE_PROP_BIT64("queue_reset", _state, _field, \ 348 VIRTIO_F_RING_RESET, true) 349 350 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n); 351 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n); 352 bool virtio_queue_enabled(VirtIODevice *vdev, int n); 353 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n); 354 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n); 355 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n); 356 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n); 357 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n); 358 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n); 359 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 360 unsigned int idx); 361 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n); 362 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n); 363 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n); 364 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n); 365 uint16_t virtio_get_queue_index(VirtQueue *vq); 366 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq); 367 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 368 bool with_irqfd); 369 int virtio_device_start_ioeventfd(VirtIODevice *vdev); 370 int virtio_device_grab_ioeventfd(VirtIODevice *vdev); 371 void virtio_device_release_ioeventfd(VirtIODevice *vdev); 372 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev); 373 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); 374 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled); 375 void virtio_queue_host_notifier_read(EventNotifier *n); 376 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx); 377 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx); 378 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx); 379 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector); 380 VirtQueue *virtio_vector_next_queue(VirtQueue *vq); 381 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev); 382 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev, 383 bool assign, bool with_irqfd); 384 385 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit) 386 { 387 assert(fbit < 64); 388 *features |= (1ULL << fbit); 389 } 390 391 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit) 392 { 393 assert(fbit < 64); 394 *features &= ~(1ULL << fbit); 395 } 396 397 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit) 398 { 399 assert(fbit < 64); 400 return !!(features & (1ULL << fbit)); 401 } 402 403 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev, 404 unsigned int fbit) 405 { 406 return virtio_has_feature(vdev->guest_features, fbit); 407 } 408 409 static inline bool virtio_host_has_feature(VirtIODevice *vdev, 410 unsigned int fbit) 411 { 412 return virtio_has_feature(vdev->host_features, fbit); 413 } 414 415 static inline bool virtio_is_big_endian(VirtIODevice *vdev) 416 { 417 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 418 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 419 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 420 } 421 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 422 return false; 423 } 424 425 /** 426 * virtio_device_started() - check if device started 427 * @vdev - the VirtIO device 428 * @status - the devices status bits 429 * 430 * Check if the device is started. For most modern machines this is 431 * tracked via the @vdev->started field (to support migration), 432 * otherwise we check for the final negotiated status bit that 433 * indicates everything is ready. 434 */ 435 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status) 436 { 437 if (vdev->use_started) { 438 return vdev->started; 439 } 440 441 return status & VIRTIO_CONFIG_S_DRIVER_OK; 442 } 443 444 /** 445 * virtio_device_should_start() - check if device startable 446 * @vdev - the VirtIO device 447 * @status - the devices status bits 448 * 449 * This is similar to virtio_device_started() but also encapsulates a 450 * check on the VM status which would prevent a device starting 451 * anyway. 452 */ 453 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status) 454 { 455 if (!vdev->vm_running) { 456 return false; 457 } 458 459 return virtio_device_started(vdev, status); 460 } 461 462 static inline void virtio_set_started(VirtIODevice *vdev, bool started) 463 { 464 if (started) { 465 vdev->start_on_kick = false; 466 } 467 468 if (vdev->use_started) { 469 vdev->started = started; 470 } 471 } 472 473 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable) 474 { 475 if (vdev->use_disabled_flag) { 476 vdev->disabled = disable; 477 } 478 } 479 480 static inline bool virtio_device_disabled(VirtIODevice *vdev) 481 { 482 return unlikely(vdev->disabled || vdev->broken); 483 } 484 485 bool virtio_legacy_allowed(VirtIODevice *vdev); 486 bool virtio_legacy_check_disabled(VirtIODevice *vdev); 487 488 #endif 489