xref: /qemu/include/hw/virtio/virtio.h (revision ea5d6ea7788c83216547fe72874033d4bf693182)
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 size_t virtio_feature_get_config_size(const VirtIOFeature *features,
53                                       uint64_t host_features);
54 
55 typedef struct VirtQueue VirtQueue;
56 
57 #define VIRTQUEUE_MAX_SIZE 1024
58 
59 typedef struct VirtQueueElement
60 {
61     unsigned int index;
62     unsigned int len;
63     unsigned int ndescs;
64     unsigned int out_num;
65     unsigned int in_num;
66     hwaddr *in_addr;
67     hwaddr *out_addr;
68     struct iovec *in_sg;
69     struct iovec *out_sg;
70 } VirtQueueElement;
71 
72 #define VIRTIO_QUEUE_MAX 1024
73 
74 #define VIRTIO_NO_VECTOR 0xffff
75 
76 #define TYPE_VIRTIO_DEVICE "virtio-device"
77 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE)
78 
79 enum virtio_device_endian {
80     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
81     VIRTIO_DEVICE_ENDIAN_LITTLE,
82     VIRTIO_DEVICE_ENDIAN_BIG,
83 };
84 
85 struct VirtIODevice
86 {
87     DeviceState parent_obj;
88     const char *name;
89     uint8_t status;
90     uint8_t isr;
91     uint16_t queue_sel;
92     uint64_t guest_features;
93     uint64_t host_features;
94     uint64_t backend_features;
95     size_t config_len;
96     void *config;
97     uint16_t config_vector;
98     uint32_t generation;
99     int nvectors;
100     VirtQueue *vq;
101     MemoryListener listener;
102     uint16_t device_id;
103     bool vm_running;
104     bool broken; /* device in invalid state, needs reset */
105     bool use_disabled_flag; /* allow use of 'disable' flag when needed */
106     bool disabled; /* device in temporarily disabled state */
107     bool use_started;
108     bool started;
109     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
110     bool disable_legacy_check;
111     bool vhost_started;
112     VMChangeStateEntry *vmstate;
113     char *bus_name;
114     uint8_t device_endian;
115     bool use_guest_notifier_mask;
116     AddressSpace *dma_as;
117     QLIST_HEAD(, VirtQueue) *vector_queues;
118 };
119 
120 struct VirtioDeviceClass {
121     /*< private >*/
122     DeviceClass parent;
123     /*< public >*/
124 
125     /* This is what a VirtioDevice must implement */
126     DeviceRealize realize;
127     DeviceUnrealize unrealize;
128     uint64_t (*get_features)(VirtIODevice *vdev,
129                              uint64_t requested_features,
130                              Error **errp);
131     uint64_t (*bad_features)(VirtIODevice *vdev);
132     void (*set_features)(VirtIODevice *vdev, uint64_t val);
133     int (*validate_features)(VirtIODevice *vdev);
134     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
135     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
136     void (*reset)(VirtIODevice *vdev);
137     void (*set_status)(VirtIODevice *vdev, uint8_t val);
138     /* For transitional devices, this is a bitmap of features
139      * that are only exposed on the legacy interface but not
140      * the modern one.
141      */
142     uint64_t legacy_features;
143     /* Test and clear event pending status.
144      * Should be called after unmask to avoid losing events.
145      * If backend does not support masking,
146      * must check in frontend instead.
147      */
148     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
149     /* Mask/unmask events from this vq. Any events reported
150      * while masked will become pending.
151      * If backend does not support masking,
152      * must mask in frontend instead.
153      */
154     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
155     int (*start_ioeventfd)(VirtIODevice *vdev);
156     void (*stop_ioeventfd)(VirtIODevice *vdev);
157     /* Saving and loading of a device; trying to deprecate save/load
158      * use vmsd for new devices.
159      */
160     void (*save)(VirtIODevice *vdev, QEMUFile *f);
161     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
162     /* Post load hook in vmsd is called early while device is processed, and
163      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
164      * unless they specifically want to verify the migration stream as it's
165      * processed, e.g. for bounds checking.
166      */
167     int (*post_load)(VirtIODevice *vdev);
168     const VMStateDescription *vmsd;
169     bool (*primary_unplug_pending)(void *opaque);
170     struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
171 };
172 
173 void virtio_instance_init_common(Object *proxy_obj, void *data,
174                                  size_t vdev_size, const char *vdev_name);
175 
176 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size);
177 
178 void virtio_cleanup(VirtIODevice *vdev);
179 
180 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3);
181 
182 /* Set the child bus name. */
183 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
184 
185 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
186 
187 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
188                             VirtIOHandleOutput handle_output);
189 
190 void virtio_del_queue(VirtIODevice *vdev, int n);
191 
192 void virtio_delete_queue(VirtQueue *vq);
193 
194 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
195                     unsigned int len);
196 void virtqueue_flush(VirtQueue *vq, unsigned int count);
197 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
198                               unsigned int len);
199 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
200                      unsigned int len);
201 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
202 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
203                     unsigned int len, unsigned int idx);
204 
205 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
206 void *virtqueue_pop(VirtQueue *vq, size_t sz);
207 unsigned int virtqueue_drop_all(VirtQueue *vq);
208 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
209 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
210                                 VirtQueueElement *elem);
211 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
212                           unsigned int out_bytes);
213 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
214                                unsigned int *out_bytes,
215                                unsigned max_in_bytes, unsigned max_out_bytes);
216 
217 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
218 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
219 
220 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
221 
222 extern const VMStateInfo virtio_vmstate_info;
223 
224 #define VMSTATE_VIRTIO_DEVICE \
225     {                                         \
226         .name = "virtio",                     \
227         .info = &virtio_vmstate_info,         \
228         .flags = VMS_SINGLE,                  \
229     }
230 
231 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
232 
233 void virtio_notify_config(VirtIODevice *vdev);
234 
235 bool virtio_queue_get_notification(VirtQueue *vq);
236 void virtio_queue_set_notification(VirtQueue *vq, int enable);
237 
238 int virtio_queue_ready(VirtQueue *vq);
239 
240 int virtio_queue_empty(VirtQueue *vq);
241 
242 /* Host binding interface.  */
243 
244 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
245 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
246 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
247 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
248 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
249 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
250 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
251 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
252 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
253 void virtio_config_modern_writeb(VirtIODevice *vdev,
254                                  uint32_t addr, uint32_t data);
255 void virtio_config_modern_writew(VirtIODevice *vdev,
256                                  uint32_t addr, uint32_t data);
257 void virtio_config_modern_writel(VirtIODevice *vdev,
258                                  uint32_t addr, uint32_t data);
259 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
260 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
261 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
262 int virtio_queue_get_num(VirtIODevice *vdev, int n);
263 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
264 int virtio_get_num_queues(VirtIODevice *vdev);
265 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
266                             hwaddr avail, hwaddr used);
267 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
268 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
269 void virtio_queue_notify(VirtIODevice *vdev, int n);
270 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
271 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
272 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
273                                       MemoryRegion *mr, bool assign);
274 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
275 void virtio_reset(void *opaque);
276 void virtio_update_irq(VirtIODevice *vdev);
277 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
278 
279 /* Base devices.  */
280 typedef struct VirtIOBlkConf VirtIOBlkConf;
281 struct virtio_net_conf;
282 typedef struct virtio_serial_conf virtio_serial_conf;
283 typedef struct virtio_input_conf virtio_input_conf;
284 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
285 typedef struct VirtIORNGConf VirtIORNGConf;
286 
287 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
288     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
289                       VIRTIO_RING_F_INDIRECT_DESC, true), \
290     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
291                       VIRTIO_RING_F_EVENT_IDX, true),     \
292     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
293                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
294     DEFINE_PROP_BIT64("any_layout", _state, _field, \
295                       VIRTIO_F_ANY_LAYOUT, true), \
296     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
297                       VIRTIO_F_IOMMU_PLATFORM, false), \
298     DEFINE_PROP_BIT64("packed", _state, _field, \
299                       VIRTIO_F_RING_PACKED, false)
300 
301 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
302 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
303 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
304 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
305 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
306 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
307 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
308 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
309 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
310 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
311                                      unsigned int idx);
312 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
313 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
314 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
315 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
316 uint16_t virtio_get_queue_index(VirtQueue *vq);
317 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
318 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
319                                                 bool with_irqfd);
320 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
321 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
322 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
323 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
324 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
325 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
326 void virtio_queue_host_notifier_read(EventNotifier *n);
327 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx);
328 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx);
329 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx);
330 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
331 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
332 
333 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
334 {
335     assert(fbit < 64);
336     *features |= (1ULL << fbit);
337 }
338 
339 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
340 {
341     assert(fbit < 64);
342     *features &= ~(1ULL << fbit);
343 }
344 
345 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
346 {
347     assert(fbit < 64);
348     return !!(features & (1ULL << fbit));
349 }
350 
351 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
352                                            unsigned int fbit)
353 {
354     return virtio_has_feature(vdev->guest_features, fbit);
355 }
356 
357 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
358                                            unsigned int fbit)
359 {
360     return virtio_has_feature(vdev->host_features, fbit);
361 }
362 
363 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
364 {
365     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
366         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
367         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
368     }
369     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
370     return false;
371 }
372 
373 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
374 {
375     if (vdev->use_started) {
376         return vdev->started;
377     }
378 
379     return status & VIRTIO_CONFIG_S_DRIVER_OK;
380 }
381 
382 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
383 {
384     if (started) {
385         vdev->start_on_kick = false;
386     }
387 
388     if (vdev->use_started) {
389         vdev->started = started;
390     }
391 }
392 
393 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
394 {
395     if (vdev->use_disabled_flag) {
396         vdev->disabled = disable;
397     }
398 }
399 
400 static inline bool virtio_device_disabled(VirtIODevice *vdev)
401 {
402     return unlikely(vdev->disabled || vdev->broken);
403 }
404 
405 bool virtio_legacy_allowed(VirtIODevice *vdev);
406 bool virtio_legacy_check_disabled(VirtIODevice *vdev);
407 
408 #endif
409