xref: /qemu/include/hw/virtio/virtio.h (revision a5ebce385763447d2ab7cb572914713eedea764a)
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 enum virtio_device_endian {
86     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
87     VIRTIO_DEVICE_ENDIAN_LITTLE,
88     VIRTIO_DEVICE_ENDIAN_BIG,
89 };
90 
91 struct VirtIODevice
92 {
93     DeviceState parent_obj;
94     const char *name;
95     uint8_t status;
96     uint8_t isr;
97     uint16_t queue_sel;
98     uint64_t guest_features;
99     uint64_t host_features;
100     uint64_t backend_features;
101     size_t config_len;
102     void *config;
103     uint16_t config_vector;
104     uint32_t generation;
105     int nvectors;
106     VirtQueue *vq;
107     MemoryListener listener;
108     uint16_t device_id;
109     /* @vm_running: current VM running state via virtio_vmstate_change() */
110     bool vm_running;
111     bool broken; /* device in invalid state, needs reset */
112     bool use_disabled_flag; /* allow use of 'disable' flag when needed */
113     bool disabled; /* device in temporarily disabled state */
114     bool use_started;
115     bool started;
116     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
117     bool disable_legacy_check;
118     bool vhost_started;
119     VMChangeStateEntry *vmstate;
120     char *bus_name;
121     uint8_t device_endian;
122     bool use_guest_notifier_mask;
123     AddressSpace *dma_as;
124     QLIST_HEAD(, VirtQueue) *vector_queues;
125     QTAILQ_ENTRY(VirtIODevice) next;
126 };
127 
128 struct VirtioDeviceClass {
129     /*< private >*/
130     DeviceClass parent;
131     /*< public >*/
132 
133     /* This is what a VirtioDevice must implement */
134     DeviceRealize realize;
135     DeviceUnrealize unrealize;
136     uint64_t (*get_features)(VirtIODevice *vdev,
137                              uint64_t requested_features,
138                              Error **errp);
139     uint64_t (*bad_features)(VirtIODevice *vdev);
140     void (*set_features)(VirtIODevice *vdev, uint64_t val);
141     int (*validate_features)(VirtIODevice *vdev);
142     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
143     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
144     void (*reset)(VirtIODevice *vdev);
145     void (*set_status)(VirtIODevice *vdev, uint8_t val);
146     /* For transitional devices, this is a bitmap of features
147      * that are only exposed on the legacy interface but not
148      * the modern one.
149      */
150     uint64_t legacy_features;
151     /* Test and clear event pending status.
152      * Should be called after unmask to avoid losing events.
153      * If backend does not support masking,
154      * must check in frontend instead.
155      */
156     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
157     /* Mask/unmask events from this vq. Any events reported
158      * while masked will become pending.
159      * If backend does not support masking,
160      * must mask in frontend instead.
161      */
162     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
163     int (*start_ioeventfd)(VirtIODevice *vdev);
164     void (*stop_ioeventfd)(VirtIODevice *vdev);
165     /* Saving and loading of a device; trying to deprecate save/load
166      * use vmsd for new devices.
167      */
168     void (*save)(VirtIODevice *vdev, QEMUFile *f);
169     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
170     /* Post load hook in vmsd is called early while device is processed, and
171      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
172      * unless they specifically want to verify the migration stream as it's
173      * processed, e.g. for bounds checking.
174      */
175     int (*post_load)(VirtIODevice *vdev);
176     const VMStateDescription *vmsd;
177     bool (*primary_unplug_pending)(void *opaque);
178     struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
179 };
180 
181 void virtio_instance_init_common(Object *proxy_obj, void *data,
182                                  size_t vdev_size, const char *vdev_name);
183 
184 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size);
185 
186 void virtio_cleanup(VirtIODevice *vdev);
187 
188 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3);
189 
190 /* Set the child bus name. */
191 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
192 
193 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
194 
195 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
196                             VirtIOHandleOutput handle_output);
197 
198 void virtio_del_queue(VirtIODevice *vdev, int n);
199 
200 void virtio_delete_queue(VirtQueue *vq);
201 
202 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
203                     unsigned int len);
204 void virtqueue_flush(VirtQueue *vq, unsigned int count);
205 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
206                               unsigned int len);
207 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
208                      unsigned int len);
209 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
210 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
211                     unsigned int len, unsigned int idx);
212 
213 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
214 void *virtqueue_pop(VirtQueue *vq, size_t sz);
215 unsigned int virtqueue_drop_all(VirtQueue *vq);
216 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
217 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
218                                 VirtQueueElement *elem);
219 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
220                           unsigned int out_bytes);
221 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
222                                unsigned int *out_bytes,
223                                unsigned max_in_bytes, unsigned max_out_bytes);
224 
225 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
226 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
227 
228 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
229 
230 extern const VMStateInfo virtio_vmstate_info;
231 
232 #define VMSTATE_VIRTIO_DEVICE \
233     {                                         \
234         .name = "virtio",                     \
235         .info = &virtio_vmstate_info,         \
236         .flags = VMS_SINGLE,                  \
237     }
238 
239 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
240 
241 void virtio_notify_config(VirtIODevice *vdev);
242 
243 bool virtio_queue_get_notification(VirtQueue *vq);
244 void virtio_queue_set_notification(VirtQueue *vq, int enable);
245 
246 int virtio_queue_ready(VirtQueue *vq);
247 
248 int virtio_queue_empty(VirtQueue *vq);
249 
250 /* Host binding interface.  */
251 
252 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
253 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
254 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
255 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
256 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
257 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
258 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
259 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
260 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
261 void virtio_config_modern_writeb(VirtIODevice *vdev,
262                                  uint32_t addr, uint32_t data);
263 void virtio_config_modern_writew(VirtIODevice *vdev,
264                                  uint32_t addr, uint32_t data);
265 void virtio_config_modern_writel(VirtIODevice *vdev,
266                                  uint32_t addr, uint32_t data);
267 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
268 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
269 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
270 int virtio_queue_get_num(VirtIODevice *vdev, int n);
271 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
272 int virtio_get_num_queues(VirtIODevice *vdev);
273 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
274                             hwaddr avail, hwaddr used);
275 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
276 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
277 void virtio_queue_notify(VirtIODevice *vdev, int n);
278 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
279 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
280 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
281                                       MemoryRegion *mr, bool assign);
282 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
283 void virtio_reset(void *opaque);
284 void virtio_update_irq(VirtIODevice *vdev);
285 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
286 
287 /* Base devices.  */
288 typedef struct VirtIOBlkConf VirtIOBlkConf;
289 struct virtio_net_conf;
290 typedef struct virtio_serial_conf virtio_serial_conf;
291 typedef struct virtio_input_conf virtio_input_conf;
292 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
293 typedef struct VirtIORNGConf VirtIORNGConf;
294 
295 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
296     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
297                       VIRTIO_RING_F_INDIRECT_DESC, true), \
298     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
299                       VIRTIO_RING_F_EVENT_IDX, true),     \
300     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
301                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
302     DEFINE_PROP_BIT64("any_layout", _state, _field, \
303                       VIRTIO_F_ANY_LAYOUT, true), \
304     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
305                       VIRTIO_F_IOMMU_PLATFORM, false), \
306     DEFINE_PROP_BIT64("packed", _state, _field, \
307                       VIRTIO_F_RING_PACKED, false)
308 
309 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
310 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
311 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
312 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
313 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
314 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
315 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
316 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
317 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
318 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
319                                      unsigned int idx);
320 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
321 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
322 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
323 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
324 uint16_t virtio_get_queue_index(VirtQueue *vq);
325 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
326 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
327                                                 bool with_irqfd);
328 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
329 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
330 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
331 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
332 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
333 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
334 void virtio_queue_host_notifier_read(EventNotifier *n);
335 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx);
336 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx);
337 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
338 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
339 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
340 
341 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
342 {
343     assert(fbit < 64);
344     *features |= (1ULL << fbit);
345 }
346 
347 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
348 {
349     assert(fbit < 64);
350     *features &= ~(1ULL << fbit);
351 }
352 
353 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
354 {
355     assert(fbit < 64);
356     return !!(features & (1ULL << fbit));
357 }
358 
359 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
360                                            unsigned int fbit)
361 {
362     return virtio_has_feature(vdev->guest_features, fbit);
363 }
364 
365 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
366                                            unsigned int fbit)
367 {
368     return virtio_has_feature(vdev->host_features, fbit);
369 }
370 
371 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
372 {
373     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
374         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
375         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
376     }
377     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
378     return false;
379 }
380 
381 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
382 {
383     if (vdev->use_started) {
384         return vdev->started;
385     }
386 
387     if (!vdev->vm_running) {
388         return false;
389     }
390 
391     return status & VIRTIO_CONFIG_S_DRIVER_OK;
392 }
393 
394 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
395 {
396     if (started) {
397         vdev->start_on_kick = false;
398     }
399 
400     if (vdev->use_started) {
401         vdev->started = started;
402     }
403 }
404 
405 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
406 {
407     if (vdev->use_disabled_flag) {
408         vdev->disabled = disable;
409     }
410 }
411 
412 static inline bool virtio_device_disabled(VirtIODevice *vdev)
413 {
414     return unlikely(vdev->disabled || vdev->broken);
415 }
416 
417 bool virtio_legacy_allowed(VirtIODevice *vdev);
418 bool virtio_legacy_check_disabled(VirtIODevice *vdev);
419 
420 #endif
421