virtio.h (17114B)
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 "hw/virtio/vhost.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 #define TYPE_VIRTIO_DEVICE "virtio-device" 83 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE) 84 85 typedef struct { 86 int virtio_bit; 87 const char *feature_desc; 88 } qmp_virtio_feature_map_t; 89 90 enum virtio_device_endian { 91 VIRTIO_DEVICE_ENDIAN_UNKNOWN, 92 VIRTIO_DEVICE_ENDIAN_LITTLE, 93 VIRTIO_DEVICE_ENDIAN_BIG, 94 }; 95 96 struct VirtIODevice 97 { 98 DeviceState parent_obj; 99 const char *name; 100 uint8_t status; 101 uint8_t isr; 102 uint16_t queue_sel; 103 uint64_t guest_features; 104 uint64_t host_features; 105 uint64_t backend_features; 106 size_t config_len; 107 void *config; 108 uint16_t config_vector; 109 uint32_t generation; 110 int nvectors; 111 VirtQueue *vq; 112 MemoryListener listener; 113 uint16_t device_id; 114 /* @vm_running: current VM running state via virtio_vmstate_change() */ 115 bool vm_running; 116 bool broken; /* device in invalid state, needs reset */ 117 bool use_disabled_flag; /* allow use of 'disable' flag when needed */ 118 bool disabled; /* device in temporarily disabled state */ 119 /** 120 * @use_started: true if the @started flag should be used to check the 121 * current state of the VirtIO device. Otherwise status bits 122 * should be checked for a current status of the device. 123 * @use_started is only set via QMP and defaults to true for all 124 * modern machines (since 4.1). 125 */ 126 bool use_started; 127 bool started; 128 bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */ 129 bool disable_legacy_check; 130 bool vhost_started; 131 VMChangeStateEntry *vmstate; 132 char *bus_name; 133 uint8_t device_endian; 134 bool use_guest_notifier_mask; 135 AddressSpace *dma_as; 136 QLIST_HEAD(, VirtQueue) *vector_queues; 137 QTAILQ_ENTRY(VirtIODevice) next; 138 }; 139 140 struct VirtioDeviceClass { 141 /*< private >*/ 142 DeviceClass parent; 143 /*< public >*/ 144 145 /* This is what a VirtioDevice must implement */ 146 DeviceRealize realize; 147 DeviceUnrealize unrealize; 148 uint64_t (*get_features)(VirtIODevice *vdev, 149 uint64_t requested_features, 150 Error **errp); 151 uint64_t (*bad_features)(VirtIODevice *vdev); 152 void (*set_features)(VirtIODevice *vdev, uint64_t val); 153 int (*validate_features)(VirtIODevice *vdev); 154 void (*get_config)(VirtIODevice *vdev, uint8_t *config); 155 void (*set_config)(VirtIODevice *vdev, const uint8_t *config); 156 void (*reset)(VirtIODevice *vdev); 157 void (*set_status)(VirtIODevice *vdev, uint8_t val); 158 /* Device must validate queue_index. */ 159 void (*queue_reset)(VirtIODevice *vdev, uint32_t queue_index); 160 /* Device must validate queue_index. */ 161 void (*queue_enable)(VirtIODevice *vdev, uint32_t queue_index); 162 /* For transitional devices, this is a bitmap of features 163 * that are only exposed on the legacy interface but not 164 * the modern one. 165 */ 166 uint64_t legacy_features; 167 /* Test and clear event pending status. 168 * Should be called after unmask to avoid losing events. 169 * If backend does not support masking, 170 * must check in frontend instead. 171 */ 172 bool (*guest_notifier_pending)(VirtIODevice *vdev, int n); 173 /* Mask/unmask events from this vq. Any events reported 174 * while masked will become pending. 175 * If backend does not support masking, 176 * must mask in frontend instead. 177 */ 178 void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask); 179 int (*start_ioeventfd)(VirtIODevice *vdev); 180 void (*stop_ioeventfd)(VirtIODevice *vdev); 181 /* Saving and loading of a device; trying to deprecate save/load 182 * use vmsd for new devices. 183 */ 184 void (*save)(VirtIODevice *vdev, QEMUFile *f); 185 int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); 186 /* Post load hook in vmsd is called early while device is processed, and 187 * when VirtIODevice isn't fully initialized. Devices should use this instead, 188 * unless they specifically want to verify the migration stream as it's 189 * processed, e.g. for bounds checking. 190 */ 191 int (*post_load)(VirtIODevice *vdev); 192 const VMStateDescription *vmsd; 193 bool (*primary_unplug_pending)(void *opaque); 194 struct vhost_dev *(*get_vhost)(VirtIODevice *vdev); 195 }; 196 197 void virtio_instance_init_common(Object *proxy_obj, void *data, 198 size_t vdev_size, const char *vdev_name); 199 200 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size); 201 202 void virtio_cleanup(VirtIODevice *vdev); 203 204 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3); 205 206 /* Set the child bus name. */ 207 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name); 208 209 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *); 210 211 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 212 VirtIOHandleOutput handle_output); 213 214 void virtio_del_queue(VirtIODevice *vdev, int n); 215 216 void virtio_delete_queue(VirtQueue *vq); 217 218 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 219 unsigned int len); 220 void virtqueue_flush(VirtQueue *vq, unsigned int count); 221 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 222 unsigned int len); 223 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 224 unsigned int len); 225 bool virtqueue_rewind(VirtQueue *vq, unsigned int num); 226 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 227 unsigned int len, unsigned int idx); 228 229 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem); 230 void *virtqueue_pop(VirtQueue *vq, size_t sz); 231 unsigned int virtqueue_drop_all(VirtQueue *vq); 232 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz); 233 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 234 VirtQueueElement *elem); 235 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 236 unsigned int out_bytes); 237 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 238 unsigned int *out_bytes, 239 unsigned max_in_bytes, unsigned max_out_bytes); 240 241 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq); 242 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq); 243 244 int virtio_save(VirtIODevice *vdev, QEMUFile *f); 245 246 extern const VMStateInfo virtio_vmstate_info; 247 248 #define VMSTATE_VIRTIO_DEVICE \ 249 { \ 250 .name = "virtio", \ 251 .info = &virtio_vmstate_info, \ 252 .flags = VMS_SINGLE, \ 253 } 254 255 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id); 256 257 void virtio_notify_config(VirtIODevice *vdev); 258 259 bool virtio_queue_get_notification(VirtQueue *vq); 260 void virtio_queue_set_notification(VirtQueue *vq, int enable); 261 262 int virtio_queue_ready(VirtQueue *vq); 263 264 int virtio_queue_empty(VirtQueue *vq); 265 266 /* Host binding interface. */ 267 268 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr); 269 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr); 270 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr); 271 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data); 272 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data); 273 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data); 274 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr); 275 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr); 276 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr); 277 void virtio_config_modern_writeb(VirtIODevice *vdev, 278 uint32_t addr, uint32_t data); 279 void virtio_config_modern_writew(VirtIODevice *vdev, 280 uint32_t addr, uint32_t data); 281 void virtio_config_modern_writel(VirtIODevice *vdev, 282 uint32_t addr, uint32_t data); 283 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr); 284 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n); 285 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num); 286 int virtio_queue_get_num(VirtIODevice *vdev, int n); 287 int virtio_queue_get_max_num(VirtIODevice *vdev, int n); 288 int virtio_get_num_queues(VirtIODevice *vdev); 289 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 290 hwaddr avail, hwaddr used); 291 void virtio_queue_update_rings(VirtIODevice *vdev, int n); 292 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align); 293 void virtio_queue_notify(VirtIODevice *vdev, int n); 294 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); 295 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector); 296 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 297 MemoryRegion *mr, bool assign); 298 int virtio_set_status(VirtIODevice *vdev, uint8_t val); 299 void virtio_reset(void *opaque); 300 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index); 301 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index); 302 void virtio_update_irq(VirtIODevice *vdev); 303 int virtio_set_features(VirtIODevice *vdev, uint64_t val); 304 305 /* Base devices. */ 306 typedef struct VirtIOBlkConf VirtIOBlkConf; 307 struct virtio_net_conf; 308 typedef struct virtio_serial_conf virtio_serial_conf; 309 typedef struct virtio_input_conf virtio_input_conf; 310 typedef struct VirtIOSCSIConf VirtIOSCSIConf; 311 typedef struct VirtIORNGConf VirtIORNGConf; 312 313 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \ 314 DEFINE_PROP_BIT64("indirect_desc", _state, _field, \ 315 VIRTIO_RING_F_INDIRECT_DESC, true), \ 316 DEFINE_PROP_BIT64("event_idx", _state, _field, \ 317 VIRTIO_RING_F_EVENT_IDX, true), \ 318 DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \ 319 VIRTIO_F_NOTIFY_ON_EMPTY, true), \ 320 DEFINE_PROP_BIT64("any_layout", _state, _field, \ 321 VIRTIO_F_ANY_LAYOUT, true), \ 322 DEFINE_PROP_BIT64("iommu_platform", _state, _field, \ 323 VIRTIO_F_IOMMU_PLATFORM, false), \ 324 DEFINE_PROP_BIT64("packed", _state, _field, \ 325 VIRTIO_F_RING_PACKED, false), \ 326 DEFINE_PROP_BIT64("queue_reset", _state, _field, \ 327 VIRTIO_F_RING_RESET, true) 328 329 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n); 330 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n); 331 bool virtio_queue_enabled(VirtIODevice *vdev, int n); 332 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n); 333 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n); 334 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n); 335 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n); 336 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n); 337 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n); 338 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 339 unsigned int idx); 340 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n); 341 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n); 342 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n); 343 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n); 344 uint16_t virtio_get_queue_index(VirtQueue *vq); 345 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq); 346 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 347 bool with_irqfd); 348 int virtio_device_start_ioeventfd(VirtIODevice *vdev); 349 int virtio_device_grab_ioeventfd(VirtIODevice *vdev); 350 void virtio_device_release_ioeventfd(VirtIODevice *vdev); 351 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev); 352 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); 353 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled); 354 void virtio_queue_host_notifier_read(EventNotifier *n); 355 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx); 356 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx); 357 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx); 358 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector); 359 VirtQueue *virtio_vector_next_queue(VirtQueue *vq); 360 361 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit) 362 { 363 assert(fbit < 64); 364 *features |= (1ULL << fbit); 365 } 366 367 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit) 368 { 369 assert(fbit < 64); 370 *features &= ~(1ULL << fbit); 371 } 372 373 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit) 374 { 375 assert(fbit < 64); 376 return !!(features & (1ULL << fbit)); 377 } 378 379 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev, 380 unsigned int fbit) 381 { 382 return virtio_has_feature(vdev->guest_features, fbit); 383 } 384 385 static inline bool virtio_host_has_feature(VirtIODevice *vdev, 386 unsigned int fbit) 387 { 388 return virtio_has_feature(vdev->host_features, fbit); 389 } 390 391 static inline bool virtio_is_big_endian(VirtIODevice *vdev) 392 { 393 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 394 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 395 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 396 } 397 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 398 return false; 399 } 400 401 /** 402 * virtio_device_started() - check if device started 403 * @vdev - the VirtIO device 404 * @status - the devices status bits 405 * 406 * Check if the device is started. For most modern machines this is 407 * tracked via the @vdev->started field (to support migration), 408 * otherwise we check for the final negotiated status bit that 409 * indicates everything is ready. 410 */ 411 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status) 412 { 413 if (vdev->use_started) { 414 return vdev->started; 415 } 416 417 return status & VIRTIO_CONFIG_S_DRIVER_OK; 418 } 419 420 /** 421 * virtio_device_should_start() - check if device startable 422 * @vdev - the VirtIO device 423 * @status - the devices status bits 424 * 425 * This is similar to virtio_device_started() but also encapsulates a 426 * check on the VM status which would prevent a device starting 427 * anyway. 428 */ 429 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status) 430 { 431 if (!vdev->vm_running) { 432 return false; 433 } 434 435 return virtio_device_started(vdev, status); 436 } 437 438 static inline void virtio_set_started(VirtIODevice *vdev, bool started) 439 { 440 if (started) { 441 vdev->start_on_kick = false; 442 } 443 444 if (vdev->use_started) { 445 vdev->started = started; 446 } 447 } 448 449 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable) 450 { 451 if (vdev->use_disabled_flag) { 452 vdev->disabled = disable; 453 } 454 } 455 456 static inline bool virtio_device_disabled(VirtIODevice *vdev) 457 { 458 return unlikely(vdev->disabled || vdev->broken); 459 } 460 461 bool virtio_legacy_allowed(VirtIODevice *vdev); 462 bool virtio_legacy_check_disabled(VirtIODevice *vdev); 463 464 #endif