include/hw/virtio/virtio.h

   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_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 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev);
 381 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
 382                                                  bool assign, bool with_irqfd);
 383
 384 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
 385 {
 386     assert(fbit < 64);
 387     *features |= (1ULL << fbit);
 388 }
 389
 390 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
 391 {
 392     assert(fbit < 64);
 393     *features &= ~(1ULL << fbit);
 394 }
 395
 396 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
 397 {
 398     assert(fbit < 64);
 399     return !!(features & (1ULL << fbit));
 400 }
 401
 402 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
 403                                            unsigned int fbit)
 404 {
 405     return virtio_has_feature(vdev->guest_features, fbit);
 406 }
 407
 408 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
 409                                            unsigned int fbit)
 410 {
 411     return virtio_has_feature(vdev->host_features, fbit);
 412 }
 413
 414 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
 415 {
 416     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
 417         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
 418         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
 419     }
 420     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
 421     return false;
 422 }
 423
 424 /**
 425  * virtio_device_started() - check if device started
 426  * @vdev - the VirtIO device
 427  * @status - the devices status bits
 428  *
 429  * Check if the device is started. For most modern machines this is
 430  * tracked via the @vdev->started field (to support migration),
 431  * otherwise we check for the final negotiated status bit that
 432  * indicates everything is ready.
 433  */
 434 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
 435 {
 436     if (vdev->use_started) {
 437         return vdev->started;
 438     }
 439
 440     return status & VIRTIO_CONFIG_S_DRIVER_OK;
 441 }
 442
 443 /**
 444  * virtio_device_should_start() - check if device startable
 445  * @vdev - the VirtIO device
 446  * @status - the devices status bits
 447  *
 448  * This is similar to virtio_device_started() but also encapsulates a
 449  * check on the VM status which would prevent a device starting
 450  * anyway.
 451  */
 452 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status)
 453 {
 454     if (!vdev->vm_running) {
 455         return false;
 456     }
 457
 458     return virtio_device_started(vdev, status);
 459 }
 460
 461 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
 462 {
 463     if (started) {
 464         vdev->start_on_kick = false;
 465     }
 466
 467     if (vdev->use_started) {
 468         vdev->started = started;
 469     }
 470 }
 471
 472 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
 473 {
 474     if (vdev->use_disabled_flag) {
 475         vdev->disabled = disable;
 476     }
 477 }
 478
 479 static inline bool virtio_device_disabled(VirtIODevice *vdev)
 480 {
 481     return unlikely(vdev->disabled || vdev->broken);
 482 }
 483
 484 bool virtio_legacy_allowed(VirtIODevice *vdev);
 485 bool virtio_legacy_check_disabled(VirtIODevice *vdev);
 486
 487 #endif