xref: /qemu/include/hw/virtio/virtio.h (revision d74c30c81159d703fb4e1caa0ec6772ff89dd02f)
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 };
126 
127 struct VirtioDeviceClass {
128     /*< private >*/
129     DeviceClass parent;
130     /*< public >*/
131 
132     /* This is what a VirtioDevice must implement */
133     DeviceRealize realize;
134     DeviceUnrealize unrealize;
135     uint64_t (*get_features)(VirtIODevice *vdev,
136                              uint64_t requested_features,
137                              Error **errp);
138     uint64_t (*bad_features)(VirtIODevice *vdev);
139     void (*set_features)(VirtIODevice *vdev, uint64_t val);
140     int (*validate_features)(VirtIODevice *vdev);
141     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
142     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
143     void (*reset)(VirtIODevice *vdev);
144     void (*set_status)(VirtIODevice *vdev, uint8_t val);
145     /* For transitional devices, this is a bitmap of features
146      * that are only exposed on the legacy interface but not
147      * the modern one.
148      */
149     uint64_t legacy_features;
150     /* Test and clear event pending status.
151      * Should be called after unmask to avoid losing events.
152      * If backend does not support masking,
153      * must check in frontend instead.
154      */
155     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
156     /* Mask/unmask events from this vq. Any events reported
157      * while masked will become pending.
158      * If backend does not support masking,
159      * must mask in frontend instead.
160      */
161     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
162     int (*start_ioeventfd)(VirtIODevice *vdev);
163     void (*stop_ioeventfd)(VirtIODevice *vdev);
164     /* Saving and loading of a device; trying to deprecate save/load
165      * use vmsd for new devices.
166      */
167     void (*save)(VirtIODevice *vdev, QEMUFile *f);
168     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
169     /* Post load hook in vmsd is called early while device is processed, and
170      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
171      * unless they specifically want to verify the migration stream as it's
172      * processed, e.g. for bounds checking.
173      */
174     int (*post_load)(VirtIODevice *vdev);
175     const VMStateDescription *vmsd;
176     bool (*primary_unplug_pending)(void *opaque);
177     struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
178 };
179 
180 void virtio_instance_init_common(Object *proxy_obj, void *data,
181                                  size_t vdev_size, const char *vdev_name);
182 
183 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size);
184 
185 void virtio_cleanup(VirtIODevice *vdev);
186 
187 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3);
188 
189 /* Set the child bus name. */
190 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
191 
192 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
193 
194 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
195                             VirtIOHandleOutput handle_output);
196 
197 void virtio_del_queue(VirtIODevice *vdev, int n);
198 
199 void virtio_delete_queue(VirtQueue *vq);
200 
201 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
202                     unsigned int len);
203 void virtqueue_flush(VirtQueue *vq, unsigned int count);
204 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
205                               unsigned int len);
206 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
207                      unsigned int len);
208 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
209 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
210                     unsigned int len, unsigned int idx);
211 
212 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
213 void *virtqueue_pop(VirtQueue *vq, size_t sz);
214 unsigned int virtqueue_drop_all(VirtQueue *vq);
215 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
216 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
217                                 VirtQueueElement *elem);
218 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
219                           unsigned int out_bytes);
220 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
221                                unsigned int *out_bytes,
222                                unsigned max_in_bytes, unsigned max_out_bytes);
223 
224 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
225 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
226 
227 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
228 
229 extern const VMStateInfo virtio_vmstate_info;
230 
231 #define VMSTATE_VIRTIO_DEVICE \
232     {                                         \
233         .name = "virtio",                     \
234         .info = &virtio_vmstate_info,         \
235         .flags = VMS_SINGLE,                  \
236     }
237 
238 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
239 
240 void virtio_notify_config(VirtIODevice *vdev);
241 
242 bool virtio_queue_get_notification(VirtQueue *vq);
243 void virtio_queue_set_notification(VirtQueue *vq, int enable);
244 
245 int virtio_queue_ready(VirtQueue *vq);
246 
247 int virtio_queue_empty(VirtQueue *vq);
248 
249 /* Host binding interface.  */
250 
251 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
252 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
253 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
254 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
255 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
256 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
257 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
258 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
259 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
260 void virtio_config_modern_writeb(VirtIODevice *vdev,
261                                  uint32_t addr, uint32_t data);
262 void virtio_config_modern_writew(VirtIODevice *vdev,
263                                  uint32_t addr, uint32_t data);
264 void virtio_config_modern_writel(VirtIODevice *vdev,
265                                  uint32_t addr, uint32_t data);
266 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
267 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
268 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
269 int virtio_queue_get_num(VirtIODevice *vdev, int n);
270 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
271 int virtio_get_num_queues(VirtIODevice *vdev);
272 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
273                             hwaddr avail, hwaddr used);
274 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
275 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
276 void virtio_queue_notify(VirtIODevice *vdev, int n);
277 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
278 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
279 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
280                                       MemoryRegion *mr, bool assign);
281 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
282 void virtio_reset(void *opaque);
283 void virtio_update_irq(VirtIODevice *vdev);
284 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
285 
286 /* Base devices.  */
287 typedef struct VirtIOBlkConf VirtIOBlkConf;
288 struct virtio_net_conf;
289 typedef struct virtio_serial_conf virtio_serial_conf;
290 typedef struct virtio_input_conf virtio_input_conf;
291 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
292 typedef struct VirtIORNGConf VirtIORNGConf;
293 
294 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
295     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
296                       VIRTIO_RING_F_INDIRECT_DESC, true), \
297     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
298                       VIRTIO_RING_F_EVENT_IDX, true),     \
299     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
300                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
301     DEFINE_PROP_BIT64("any_layout", _state, _field, \
302                       VIRTIO_F_ANY_LAYOUT, true), \
303     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
304                       VIRTIO_F_IOMMU_PLATFORM, false), \
305     DEFINE_PROP_BIT64("packed", _state, _field, \
306                       VIRTIO_F_RING_PACKED, false)
307 
308 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
309 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
310 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
311 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
312 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
313 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
314 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
315 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
316 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
317 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
318                                      unsigned int idx);
319 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
320 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
321 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
322 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
323 uint16_t virtio_get_queue_index(VirtQueue *vq);
324 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
325 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
326                                                 bool with_irqfd);
327 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
328 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
329 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
330 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
331 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
332 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
333 void virtio_queue_host_notifier_read(EventNotifier *n);
334 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx);
335 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx);
336 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
337 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
338 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
339 
340 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
341 {
342     assert(fbit < 64);
343     *features |= (1ULL << fbit);
344 }
345 
346 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
347 {
348     assert(fbit < 64);
349     *features &= ~(1ULL << fbit);
350 }
351 
352 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
353 {
354     assert(fbit < 64);
355     return !!(features & (1ULL << fbit));
356 }
357 
358 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
359                                            unsigned int fbit)
360 {
361     return virtio_has_feature(vdev->guest_features, fbit);
362 }
363 
364 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
365                                            unsigned int fbit)
366 {
367     return virtio_has_feature(vdev->host_features, fbit);
368 }
369 
370 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
371 {
372     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
373         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
374         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
375     }
376     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
377     return false;
378 }
379 
380 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
381 {
382     if (vdev->use_started) {
383         return vdev->started;
384     }
385 
386     if (!vdev->vm_running) {
387         return false;
388     }
389 
390     return status & VIRTIO_CONFIG_S_DRIVER_OK;
391 }
392 
393 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
394 {
395     if (started) {
396         vdev->start_on_kick = false;
397     }
398 
399     if (vdev->use_started) {
400         vdev->started = started;
401     }
402 }
403 
404 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
405 {
406     if (vdev->use_disabled_flag) {
407         vdev->disabled = disable;
408     }
409 }
410 
411 static inline bool virtio_device_disabled(VirtIODevice *vdev)
412 {
413     return unlikely(vdev->disabled || vdev->broken);
414 }
415 
416 bool virtio_legacy_allowed(VirtIODevice *vdev);
417 bool virtio_legacy_check_disabled(VirtIODevice *vdev);
418 
419 #endif
420