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 /* 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 bool use_guest_notifier_mask; 155 AddressSpace *dma_as; 156 QLIST_HEAD(, VirtQueue) *vector_queues; 157 QTAILQ_ENTRY(VirtIODevice) next; 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_queue_set_align(VirtIODevice *vdev, int n, int align); 313 void virtio_queue_notify(VirtIODevice *vdev, int n); 314 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); 315 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector); 316 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 317 MemoryRegion *mr, bool assign); 318 int virtio_set_status(VirtIODevice *vdev, uint8_t val); 319 void virtio_reset(void *opaque); 320 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index); 321 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index); 322 void virtio_update_irq(VirtIODevice *vdev); 323 int virtio_set_features(VirtIODevice *vdev, uint64_t val); 324 325 /* Base devices. */ 326 typedef struct VirtIOBlkConf VirtIOBlkConf; 327 struct virtio_net_conf; 328 typedef struct virtio_serial_conf virtio_serial_conf; 329 typedef struct virtio_input_conf virtio_input_conf; 330 typedef struct VirtIOSCSIConf VirtIOSCSIConf; 331 typedef struct VirtIORNGConf VirtIORNGConf; 332 333 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \ 334 DEFINE_PROP_BIT64("indirect_desc", _state, _field, \ 335 VIRTIO_RING_F_INDIRECT_DESC, true), \ 336 DEFINE_PROP_BIT64("event_idx", _state, _field, \ 337 VIRTIO_RING_F_EVENT_IDX, true), \ 338 DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \ 339 VIRTIO_F_NOTIFY_ON_EMPTY, true), \ 340 DEFINE_PROP_BIT64("any_layout", _state, _field, \ 341 VIRTIO_F_ANY_LAYOUT, true), \ 342 DEFINE_PROP_BIT64("iommu_platform", _state, _field, \ 343 VIRTIO_F_IOMMU_PLATFORM, false), \ 344 DEFINE_PROP_BIT64("packed", _state, _field, \ 345 VIRTIO_F_RING_PACKED, false), \ 346 DEFINE_PROP_BIT64("queue_reset", _state, _field, \ 347 VIRTIO_F_RING_RESET, true) 348 349 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n); 350 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n); 351 bool virtio_queue_enabled(VirtIODevice *vdev, int n); 352 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n); 353 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n); 354 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n); 355 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n); 356 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n); 357 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n); 358 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 359 unsigned int idx); 360 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n); 361 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n); 362 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n); 363 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n); 364 uint16_t virtio_get_queue_index(VirtQueue *vq); 365 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq); 366 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 367 bool with_irqfd); 368 int virtio_device_start_ioeventfd(VirtIODevice *vdev); 369 int virtio_device_grab_ioeventfd(VirtIODevice *vdev); 370 void virtio_device_release_ioeventfd(VirtIODevice *vdev); 371 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev); 372 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); 373 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled); 374 void virtio_queue_host_notifier_read(EventNotifier *n); 375 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx); 376 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx); 377 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx); 378 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector); 379 VirtQueue *virtio_vector_next_queue(VirtQueue *vq); 380 381 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit) 382 { 383 assert(fbit < 64); 384 *features |= (1ULL << fbit); 385 } 386 387 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit) 388 { 389 assert(fbit < 64); 390 *features &= ~(1ULL << fbit); 391 } 392 393 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit) 394 { 395 assert(fbit < 64); 396 return !!(features & (1ULL << fbit)); 397 } 398 399 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev, 400 unsigned int fbit) 401 { 402 return virtio_has_feature(vdev->guest_features, fbit); 403 } 404 405 static inline bool virtio_host_has_feature(VirtIODevice *vdev, 406 unsigned int fbit) 407 { 408 return virtio_has_feature(vdev->host_features, fbit); 409 } 410 411 static inline bool virtio_is_big_endian(VirtIODevice *vdev) 412 { 413 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 414 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 415 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 416 } 417 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 418 return false; 419 } 420 421 /** 422 * virtio_device_started() - check if device started 423 * @vdev - the VirtIO device 424 * @status - the devices status bits 425 * 426 * Check if the device is started. For most modern machines this is 427 * tracked via the @vdev->started field (to support migration), 428 * otherwise we check for the final negotiated status bit that 429 * indicates everything is ready. 430 */ 431 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status) 432 { 433 if (vdev->use_started) { 434 return vdev->started; 435 } 436 437 return status & VIRTIO_CONFIG_S_DRIVER_OK; 438 } 439 440 /** 441 * virtio_device_should_start() - check if device startable 442 * @vdev - the VirtIO device 443 * @status - the devices status bits 444 * 445 * This is similar to virtio_device_started() but also encapsulates a 446 * check on the VM status which would prevent a device starting 447 * anyway. 448 */ 449 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status) 450 { 451 if (!vdev->vm_running) { 452 return false; 453 } 454 455 return virtio_device_started(vdev, status); 456 } 457 458 static inline void virtio_set_started(VirtIODevice *vdev, bool started) 459 { 460 if (started) { 461 vdev->start_on_kick = false; 462 } 463 464 if (vdev->use_started) { 465 vdev->started = started; 466 } 467 } 468 469 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable) 470 { 471 if (vdev->use_disabled_flag) { 472 vdev->disabled = disable; 473 } 474 } 475 476 static inline bool virtio_device_disabled(VirtIODevice *vdev) 477 { 478 return unlikely(vdev->disabled || vdev->broken); 479 } 480 481 bool virtio_legacy_allowed(VirtIODevice *vdev); 482 bool virtio_legacy_check_disabled(VirtIODevice *vdev); 483 484 #endif 485