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