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 "block/aio.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
vring_align(hwaddr addr,unsigned long align)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 /* Element has been processed (VIRTIO_F_IN_ORDER) */
73 bool in_order_filled;
74 hwaddr *in_addr;
75 hwaddr *out_addr;
76 struct iovec *in_sg;
77 struct iovec *out_sg;
78 } VirtQueueElement;
79
80 #define VIRTIO_QUEUE_MAX 1024
81
82 #define VIRTIO_NO_VECTOR 0xffff
83
84 /* special index value used internally for config irqs */
85 #define VIRTIO_CONFIG_IRQ_IDX -1
86
87 #define TYPE_VIRTIO_DEVICE "virtio-device"
88 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE)
89
90 typedef struct {
91 int virtio_bit;
92 const char *feature_desc;
93 } qmp_virtio_feature_map_t;
94
95 enum virtio_device_endian {
96 VIRTIO_DEVICE_ENDIAN_UNKNOWN,
97 VIRTIO_DEVICE_ENDIAN_LITTLE,
98 VIRTIO_DEVICE_ENDIAN_BIG,
99 };
100
101 /**
102 * struct VirtIODevice - common VirtIO structure
103 * @name: name of the device
104 * @status: VirtIO Device Status field
105 *
106 */
107 struct VirtIODevice
108 {
109 DeviceState parent_obj;
110 const char *name;
111 uint8_t status;
112 uint8_t isr;
113 uint16_t queue_sel;
114 /**
115 * These fields represent a set of VirtIO features at various
116 * levels of the stack. @host_features indicates the complete
117 * feature set the VirtIO device can offer to the driver.
118 * @guest_features indicates which features the VirtIO driver has
119 * selected by writing to the feature register. Finally
120 * @backend_features represents everything supported by the
121 * backend (e.g. vhost) and could potentially be a subset of the
122 * total feature set offered by QEMU.
123 */
124 uint64_t host_features;
125 uint64_t guest_features;
126 uint64_t backend_features;
127
128 size_t config_len;
129 void *config;
130 uint16_t config_vector;
131 uint32_t generation;
132 int nvectors;
133 VirtQueue *vq;
134 MemoryListener listener;
135 uint16_t device_id;
136 /* @vm_running: current VM running state via virtio_vmstate_change() */
137 bool vm_running;
138 bool broken; /* device in invalid state, needs reset */
139 bool use_disabled_flag; /* allow use of 'disable' flag when needed */
140 bool disabled; /* device in temporarily disabled state */
141 /**
142 * @use_started: true if the @started flag should be used to check the
143 * current state of the VirtIO device. Otherwise status bits
144 * should be checked for a current status of the device.
145 * @use_started is only set via QMP and defaults to true for all
146 * modern machines (since 4.1).
147 */
148 bool use_started;
149 bool started;
150 bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
151 bool disable_legacy_check;
152 bool vhost_started;
153 VMChangeStateEntry *vmstate;
154 char *bus_name;
155 uint8_t device_endian;
156 /**
157 * @user_guest_notifier_mask: gate usage of ->guest_notifier_mask() callback.
158 * This is used to suppress the masking of guest updates for
159 * vhost-user devices which are asynchronous by design.
160 */
161 bool use_guest_notifier_mask;
162 AddressSpace *dma_as;
163 QLIST_HEAD(, VirtQueue) *vector_queues;
164 QTAILQ_ENTRY(VirtIODevice) next;
165 /**
166 * @config_notifier: the event notifier that handles config events
167 */
168 EventNotifier config_notifier;
169 bool device_iotlb_enabled;
170 };
171
172 struct VirtioDeviceClass {
173 /*< private >*/
174 DeviceClass parent;
175 /*< public >*/
176
177 /* This is what a VirtioDevice must implement */
178 DeviceRealize realize;
179 DeviceUnrealize unrealize;
180 uint64_t (*get_features)(VirtIODevice *vdev,
181 uint64_t requested_features,
182 Error **errp);
183 uint64_t (*bad_features)(VirtIODevice *vdev);
184 void (*set_features)(VirtIODevice *vdev, uint64_t val);
185 int (*validate_features)(VirtIODevice *vdev);
186 void (*get_config)(VirtIODevice *vdev, uint8_t *config);
187 void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
188 void (*reset)(VirtIODevice *vdev);
189 void (*set_status)(VirtIODevice *vdev, uint8_t val);
190 /* Device must validate queue_index. */
191 void (*queue_reset)(VirtIODevice *vdev, uint32_t queue_index);
192 /* Device must validate queue_index. */
193 void (*queue_enable)(VirtIODevice *vdev, uint32_t queue_index);
194 /* For transitional devices, this is a bitmap of features
195 * that are only exposed on the legacy interface but not
196 * the modern one.
197 */
198 uint64_t legacy_features;
199 /* Test and clear event pending status.
200 * Should be called after unmask to avoid losing events.
201 * If backend does not support masking,
202 * must check in frontend instead.
203 */
204 bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
205 /* Mask/unmask events from this vq. Any events reported
206 * while masked will become pending.
207 * If backend does not support masking,
208 * must mask in frontend instead.
209 */
210 void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
211 int (*start_ioeventfd)(VirtIODevice *vdev);
212 void (*stop_ioeventfd)(VirtIODevice *vdev);
213 /* Saving and loading of a device; trying to deprecate save/load
214 * use vmsd for new devices.
215 */
216 void (*save)(VirtIODevice *vdev, QEMUFile *f);
217 int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
218 /* Post load hook in vmsd is called early while device is processed, and
219 * when VirtIODevice isn't fully initialized. Devices should use this instead,
220 * unless they specifically want to verify the migration stream as it's
221 * processed, e.g. for bounds checking.
222 */
223 int (*post_load)(VirtIODevice *vdev);
224 const VMStateDescription *vmsd;
225 bool (*primary_unplug_pending)(void *opaque);
226 /* May be called even when vdev->vhost_started is false */
227 struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
228 void (*toggle_device_iotlb)(VirtIODevice *vdev);
229 };
230
231 void virtio_instance_init_common(Object *proxy_obj, void *data,
232 size_t vdev_size, const char *vdev_name);
233
234 /**
235 * virtio_init() - initialise the common VirtIODevice structure
236 * @vdev: pointer to VirtIODevice
237 * @device_id: the VirtIO device ID (see virtio_ids.h)
238 * @config_size: size of the config space
239 */
240 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size);
241
242 void virtio_cleanup(VirtIODevice *vdev);
243
244 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3);
245
246 /* Set the child bus name. */
247 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
248
249 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
250
251 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
252 VirtIOHandleOutput handle_output);
253
254 void virtio_del_queue(VirtIODevice *vdev, int n);
255
256 void virtio_delete_queue(VirtQueue *vq);
257
258 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
259 unsigned int len);
260 void virtqueue_flush(VirtQueue *vq, unsigned int count);
261 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
262 unsigned int len);
263 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
264 unsigned int len);
265 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
266 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
267 unsigned int len, unsigned int idx);
268
269 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
270 void *virtqueue_pop(VirtQueue *vq, size_t sz);
271 unsigned int virtqueue_drop_all(VirtQueue *vq);
272 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
273 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
274 VirtQueueElement *elem);
275 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
276 unsigned int out_bytes);
277 /**
278 * Return <0 on error or an opaque >=0 to pass to
279 * virtio_queue_enable_notification_and_check on success.
280 */
281 int virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
282 unsigned int *out_bytes, unsigned max_in_bytes,
283 unsigned max_out_bytes);
284
285 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
286 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
287
288 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
289
290 extern const VMStateInfo virtio_vmstate_info;
291
292 #define VMSTATE_VIRTIO_DEVICE \
293 { \
294 .name = "virtio", \
295 .info = &virtio_vmstate_info, \
296 .flags = VMS_SINGLE, \
297 }
298
299 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
300
301 /**
302 * virtio_notify_config() - signal a change to device config
303 * @vdev: the virtio device
304 *
305 * Assuming the virtio device is up (VIRTIO_CONFIG_S_DRIVER_OK) this
306 * will trigger a guest interrupt and update the config version.
307 */
308 void virtio_notify_config(VirtIODevice *vdev);
309
310 bool virtio_queue_get_notification(VirtQueue *vq);
311 void virtio_queue_set_notification(VirtQueue *vq, int enable);
312
313 int virtio_queue_ready(VirtQueue *vq);
314
315 int virtio_queue_empty(VirtQueue *vq);
316
317 /**
318 * Enable notification and check whether guest has added some
319 * buffers since last call to virtqueue_get_avail_bytes.
320 *
321 * @opaque: value returned from virtqueue_get_avail_bytes
322 */
323 bool virtio_queue_enable_notification_and_check(VirtQueue *vq,
324 int opaque);
325
326 void virtio_queue_set_shadow_avail_idx(VirtQueue *vq, uint16_t idx);
327
328 /* Host binding interface. */
329
330 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
331 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
332 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
333 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
334 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
335 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
336 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
337 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
338 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
339 void virtio_config_modern_writeb(VirtIODevice *vdev,
340 uint32_t addr, uint32_t data);
341 void virtio_config_modern_writew(VirtIODevice *vdev,
342 uint32_t addr, uint32_t data);
343 void virtio_config_modern_writel(VirtIODevice *vdev,
344 uint32_t addr, uint32_t data);
345 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
346 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
347 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
348 int virtio_queue_get_num(VirtIODevice *vdev, int n);
349 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
350 int virtio_get_num_queues(VirtIODevice *vdev);
351 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
352 hwaddr avail, hwaddr used);
353 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
354 void virtio_init_region_cache(VirtIODevice *vdev, int n);
355 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
356 void virtio_queue_notify(VirtIODevice *vdev, int n);
357 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
358 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
359 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
360 MemoryRegion *mr, bool assign);
361 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
362 void virtio_reset(void *opaque);
363 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index);
364 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index);
365 void virtio_update_irq(VirtIODevice *vdev);
366 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
367
368 /* Base devices. */
369 typedef struct VirtIOBlkConf VirtIOBlkConf;
370 struct virtio_net_conf;
371 typedef struct virtio_serial_conf virtio_serial_conf;
372 typedef struct virtio_input_conf virtio_input_conf;
373 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
374 typedef struct VirtIORNGConf VirtIORNGConf;
375
376 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
377 DEFINE_PROP_BIT64("indirect_desc", _state, _field, \
378 VIRTIO_RING_F_INDIRECT_DESC, true), \
379 DEFINE_PROP_BIT64("event_idx", _state, _field, \
380 VIRTIO_RING_F_EVENT_IDX, true), \
381 DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \
382 VIRTIO_F_NOTIFY_ON_EMPTY, true), \
383 DEFINE_PROP_BIT64("any_layout", _state, _field, \
384 VIRTIO_F_ANY_LAYOUT, true), \
385 DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
386 VIRTIO_F_IOMMU_PLATFORM, false), \
387 DEFINE_PROP_BIT64("packed", _state, _field, \
388 VIRTIO_F_RING_PACKED, false), \
389 DEFINE_PROP_BIT64("queue_reset", _state, _field, \
390 VIRTIO_F_RING_RESET, true), \
391 DEFINE_PROP_BIT64("in_order", _state, _field, \
392 VIRTIO_F_IN_ORDER, false)
393
394 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
395 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
396 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
397 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
398 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
399 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
400 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
401 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
402 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
403 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
404 unsigned int idx);
405 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
406 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
407 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
408 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
409 uint16_t virtio_get_queue_index(VirtQueue *vq);
410 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
411 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
412 bool with_irqfd);
413 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
414 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
415 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
416 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
417 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
418 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
419 void virtio_queue_host_notifier_read(EventNotifier *n);
420 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx);
421 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx);
422 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
423 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
424 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
425 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev);
426 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev,
427 bool assign, bool with_irqfd);
428
virtio_add_feature(uint64_t * features,unsigned int fbit)429 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
430 {
431 assert(fbit < 64);
432 *features |= (1ULL << fbit);
433 }
434
virtio_clear_feature(uint64_t * features,unsigned int fbit)435 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
436 {
437 assert(fbit < 64);
438 *features &= ~(1ULL << fbit);
439 }
440
virtio_has_feature(uint64_t features,unsigned int fbit)441 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
442 {
443 assert(fbit < 64);
444 return !!(features & (1ULL << fbit));
445 }
446
virtio_vdev_has_feature(const VirtIODevice * vdev,unsigned int fbit)447 static inline bool virtio_vdev_has_feature(const VirtIODevice *vdev,
448 unsigned int fbit)
449 {
450 return virtio_has_feature(vdev->guest_features, fbit);
451 }
452
virtio_host_has_feature(VirtIODevice * vdev,unsigned int fbit)453 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
454 unsigned int fbit)
455 {
456 return virtio_has_feature(vdev->host_features, fbit);
457 }
458
virtio_is_big_endian(VirtIODevice * vdev)459 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
460 {
461 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
462 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
463 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
464 }
465 /* Devices conforming to VIRTIO 1.0 or later are always LE. */
466 return false;
467 }
468
469 /**
470 * virtio_device_started() - check if device started
471 * @vdev - the VirtIO device
472 * @status - the devices status bits
473 *
474 * Check if the device is started. For most modern machines this is
475 * tracked via the @vdev->started field (to support migration),
476 * otherwise we check for the final negotiated status bit that
477 * indicates everything is ready.
478 */
virtio_device_started(VirtIODevice * vdev,uint8_t status)479 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
480 {
481 if (vdev->use_started) {
482 return vdev->started;
483 }
484
485 return status & VIRTIO_CONFIG_S_DRIVER_OK;
486 }
487
488 /**
489 * virtio_device_should_start() - check if device startable
490 * @vdev - the VirtIO device
491 * @status - the devices status bits
492 *
493 * This is similar to virtio_device_started() but ignores vdev->started
494 * and also encapsulates a check on the VM status which would prevent a
495 * device from starting anyway.
496 */
virtio_device_should_start(VirtIODevice * vdev,uint8_t status)497 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status)
498 {
499 if (!vdev->vm_running) {
500 return false;
501 }
502
503 return status & VIRTIO_CONFIG_S_DRIVER_OK;
504 }
505
virtio_set_started(VirtIODevice * vdev,bool started)506 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
507 {
508 if (started) {
509 vdev->start_on_kick = false;
510 }
511
512 if (vdev->use_started) {
513 vdev->started = started;
514 }
515 }
516
virtio_set_disabled(VirtIODevice * vdev,bool disable)517 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
518 {
519 if (vdev->use_disabled_flag) {
520 vdev->disabled = disable;
521 }
522 }
523
virtio_device_disabled(VirtIODevice * vdev)524 static inline bool virtio_device_disabled(VirtIODevice *vdev)
525 {
526 return unlikely(vdev->disabled || vdev->broken);
527 }
528
529 bool virtio_legacy_allowed(VirtIODevice *vdev);
530 bool virtio_legacy_check_disabled(VirtIODevice *vdev);
531
532 QEMUBH *virtio_bh_new_guarded_full(DeviceState *dev,
533 QEMUBHFunc *cb, void *opaque,
534 const char *name);
535 #define virtio_bh_new_guarded(dev, cb, opaque) \
536 virtio_bh_new_guarded_full((dev), (cb), (opaque), (stringify(cb)))
537
538 #endif
539