xref: /qemu/include/hw/virtio/virtio.h (revision db1015e92e04835c9eb50c29625fe566d1202dbd)
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 /* A guest should never accept this.  It implies negotiation is broken. */
27 #define VIRTIO_F_BAD_FEATURE		30
28 
29 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \
30                                 (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
31                                 (0x1ULL << VIRTIO_F_ANY_LAYOUT))
32 
33 struct VirtQueue;
34 
35 static inline hwaddr vring_align(hwaddr addr,
36                                              unsigned long align)
37 {
38     return QEMU_ALIGN_UP(addr, align);
39 }
40 
41 typedef struct VirtIOFeature {
42     uint64_t flags;
43     size_t end;
44 } VirtIOFeature;
45 
46 size_t virtio_feature_get_config_size(VirtIOFeature *features,
47                                       uint64_t host_features);
48 
49 typedef struct VirtQueue VirtQueue;
50 
51 #define VIRTQUEUE_MAX_SIZE 1024
52 
53 typedef struct VirtQueueElement
54 {
55     unsigned int index;
56     unsigned int len;
57     unsigned int ndescs;
58     unsigned int out_num;
59     unsigned int in_num;
60     hwaddr *in_addr;
61     hwaddr *out_addr;
62     struct iovec *in_sg;
63     struct iovec *out_sg;
64 } VirtQueueElement;
65 
66 #define VIRTIO_QUEUE_MAX 1024
67 
68 #define VIRTIO_NO_VECTOR 0xffff
69 
70 #define TYPE_VIRTIO_DEVICE "virtio-device"
71 typedef struct VirtioDeviceClass VirtioDeviceClass;
72 #define VIRTIO_DEVICE_GET_CLASS(obj) \
73         OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
74 #define VIRTIO_DEVICE_CLASS(klass) \
75         OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
76 #define VIRTIO_DEVICE(obj) \
77         OBJECT_CHECK(VirtIODevice, (obj), TYPE_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     VMChangeStateEntry *vmstate;
111     char *bus_name;
112     uint8_t device_endian;
113     bool use_guest_notifier_mask;
114     AddressSpace *dma_as;
115     QLIST_HEAD(, VirtQueue) *vector_queues;
116 };
117 
118 struct VirtioDeviceClass {
119     /*< private >*/
120     DeviceClass parent;
121     /*< public >*/
122 
123     /* This is what a VirtioDevice must implement */
124     DeviceRealize realize;
125     DeviceUnrealize unrealize;
126     uint64_t (*get_features)(VirtIODevice *vdev,
127                              uint64_t requested_features,
128                              Error **errp);
129     uint64_t (*bad_features)(VirtIODevice *vdev);
130     void (*set_features)(VirtIODevice *vdev, uint64_t val);
131     int (*validate_features)(VirtIODevice *vdev);
132     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
133     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
134     void (*reset)(VirtIODevice *vdev);
135     void (*set_status)(VirtIODevice *vdev, uint8_t val);
136     /* For transitional devices, this is a bitmap of features
137      * that are only exposed on the legacy interface but not
138      * the modern one.
139      */
140     uint64_t legacy_features;
141     /* Test and clear event pending status.
142      * Should be called after unmask to avoid losing events.
143      * If backend does not support masking,
144      * must check in frontend instead.
145      */
146     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
147     /* Mask/unmask events from this vq. Any events reported
148      * while masked will become pending.
149      * If backend does not support masking,
150      * must mask in frontend instead.
151      */
152     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
153     int (*start_ioeventfd)(VirtIODevice *vdev);
154     void (*stop_ioeventfd)(VirtIODevice *vdev);
155     /* Saving and loading of a device; trying to deprecate save/load
156      * use vmsd for new devices.
157      */
158     void (*save)(VirtIODevice *vdev, QEMUFile *f);
159     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
160     /* Post load hook in vmsd is called early while device is processed, and
161      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
162      * unless they specifically want to verify the migration stream as it's
163      * processed, e.g. for bounds checking.
164      */
165     int (*post_load)(VirtIODevice *vdev);
166     const VMStateDescription *vmsd;
167     bool (*primary_unplug_pending)(void *opaque);
168 };
169 
170 void virtio_instance_init_common(Object *proxy_obj, void *data,
171                                  size_t vdev_size, const char *vdev_name);
172 
173 void virtio_init(VirtIODevice *vdev, const char *name,
174                          uint16_t device_id, size_t config_size);
175 void virtio_cleanup(VirtIODevice *vdev);
176 
177 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
178 
179 /* Set the child bus name. */
180 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
181 
182 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
183 typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
184 
185 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
186                             VirtIOHandleOutput handle_output);
187 
188 void virtio_del_queue(VirtIODevice *vdev, int n);
189 
190 void virtio_delete_queue(VirtQueue *vq);
191 
192 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
193                     unsigned int len);
194 void virtqueue_flush(VirtQueue *vq, unsigned int count);
195 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
196                               unsigned int len);
197 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
198                      unsigned int len);
199 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
200 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
201                     unsigned int len, unsigned int idx);
202 
203 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
204 void *virtqueue_pop(VirtQueue *vq, size_t sz);
205 unsigned int virtqueue_drop_all(VirtQueue *vq);
206 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
207 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
208                                 VirtQueueElement *elem);
209 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
210                           unsigned int out_bytes);
211 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
212                                unsigned int *out_bytes,
213                                unsigned max_in_bytes, unsigned max_out_bytes);
214 
215 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
216 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
217 
218 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
219 
220 extern const VMStateInfo virtio_vmstate_info;
221 
222 #define VMSTATE_VIRTIO_DEVICE \
223     {                                         \
224         .name = "virtio",                     \
225         .info = &virtio_vmstate_info,         \
226         .flags = VMS_SINGLE,                  \
227     }
228 
229 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
230 
231 void virtio_notify_config(VirtIODevice *vdev);
232 
233 bool virtio_queue_get_notification(VirtQueue *vq);
234 void virtio_queue_set_notification(VirtQueue *vq, int enable);
235 
236 int virtio_queue_ready(VirtQueue *vq);
237 
238 int virtio_queue_empty(VirtQueue *vq);
239 
240 /* Host binding interface.  */
241 
242 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
243 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
244 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
245 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
246 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
247 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
248 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
249 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
250 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
251 void virtio_config_modern_writeb(VirtIODevice *vdev,
252                                  uint32_t addr, uint32_t data);
253 void virtio_config_modern_writew(VirtIODevice *vdev,
254                                  uint32_t addr, uint32_t data);
255 void virtio_config_modern_writel(VirtIODevice *vdev,
256                                  uint32_t addr, uint32_t data);
257 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
258 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
259 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
260 int virtio_queue_get_num(VirtIODevice *vdev, int n);
261 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
262 int virtio_get_num_queues(VirtIODevice *vdev);
263 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
264                             hwaddr avail, hwaddr used);
265 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
266 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
267 void virtio_queue_notify(VirtIODevice *vdev, int n);
268 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
269 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
270 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
271                                       MemoryRegion *mr, bool assign);
272 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
273 void virtio_reset(void *opaque);
274 void virtio_update_irq(VirtIODevice *vdev);
275 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
276 
277 /* Base devices.  */
278 typedef struct VirtIOBlkConf VirtIOBlkConf;
279 struct virtio_net_conf;
280 typedef struct virtio_serial_conf virtio_serial_conf;
281 typedef struct virtio_input_conf virtio_input_conf;
282 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
283 typedef struct VirtIORNGConf VirtIORNGConf;
284 
285 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
286     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
287                       VIRTIO_RING_F_INDIRECT_DESC, true), \
288     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
289                       VIRTIO_RING_F_EVENT_IDX, true),     \
290     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
291                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
292     DEFINE_PROP_BIT64("any_layout", _state, _field, \
293                       VIRTIO_F_ANY_LAYOUT, true), \
294     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
295                       VIRTIO_F_IOMMU_PLATFORM, false), \
296     DEFINE_PROP_BIT64("packed", _state, _field, \
297                       VIRTIO_F_RING_PACKED, false)
298 
299 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
300 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
301 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
302 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
303 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
304 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
305 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
306 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
307 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
308 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
309                                      unsigned int idx);
310 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
311 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
312 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
313 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
314 uint16_t virtio_get_queue_index(VirtQueue *vq);
315 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
316 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
317                                                 bool with_irqfd);
318 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
319 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
320 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
321 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
322 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
323 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
324 void virtio_queue_host_notifier_read(EventNotifier *n);
325 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
326                                                 VirtIOHandleAIOOutput handle_output);
327 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
328 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
329 
330 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
331 {
332     assert(fbit < 64);
333     *features |= (1ULL << fbit);
334 }
335 
336 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
337 {
338     assert(fbit < 64);
339     *features &= ~(1ULL << fbit);
340 }
341 
342 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
343 {
344     assert(fbit < 64);
345     return !!(features & (1ULL << fbit));
346 }
347 
348 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
349                                            unsigned int fbit)
350 {
351     return virtio_has_feature(vdev->guest_features, fbit);
352 }
353 
354 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
355                                            unsigned int fbit)
356 {
357     return virtio_has_feature(vdev->host_features, fbit);
358 }
359 
360 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
361 {
362     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
363         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
364         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
365     }
366     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
367     return false;
368 }
369 
370 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
371 {
372     if (vdev->use_started) {
373         return vdev->started;
374     }
375 
376     return status & VIRTIO_CONFIG_S_DRIVER_OK;
377 }
378 
379 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
380 {
381     if (started) {
382         vdev->start_on_kick = false;
383     }
384 
385     if (vdev->use_started) {
386         vdev->started = started;
387     }
388 }
389 
390 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
391 {
392     if (vdev->use_disabled_flag) {
393         vdev->disabled = disable;
394     }
395 }
396 
397 static inline bool virtio_device_disabled(VirtIODevice *vdev)
398 {
399     return unlikely(vdev->disabled || vdev->broken);
400 }
401 
402 bool virtio_legacy_allowed(VirtIODevice *vdev);
403 
404 #endif
405