xref: /qemu/include/hw/virtio/virtio.h (revision 1cfe28cdcabd10e31b0e05db8a2cfd9993f315e2)
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 
25 /* A guest should never accept this.  It implies negotiation is broken. */
26 #define VIRTIO_F_BAD_FEATURE		30
27 
28 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \
29                                 (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
30                                 (0x1ULL << VIRTIO_F_ANY_LAYOUT))
31 
32 struct VirtQueue;
33 
34 static inline hwaddr vring_align(hwaddr addr,
35                                              unsigned long align)
36 {
37     return QEMU_ALIGN_UP(addr, align);
38 }
39 
40 typedef struct VirtIOFeature {
41     uint64_t flags;
42     size_t end;
43 } VirtIOFeature;
44 
45 size_t virtio_feature_get_config_size(VirtIOFeature *features,
46                                       uint64_t host_features);
47 
48 typedef struct VirtQueue VirtQueue;
49 
50 #define VIRTQUEUE_MAX_SIZE 1024
51 
52 typedef struct VirtQueueElement
53 {
54     unsigned int index;
55     unsigned int len;
56     unsigned int ndescs;
57     unsigned int out_num;
58     unsigned int in_num;
59     hwaddr *in_addr;
60     hwaddr *out_addr;
61     struct iovec *in_sg;
62     struct iovec *out_sg;
63 } VirtQueueElement;
64 
65 #define VIRTIO_QUEUE_MAX 1024
66 
67 #define VIRTIO_NO_VECTOR 0xffff
68 
69 #define TYPE_VIRTIO_DEVICE "virtio-device"
70 #define VIRTIO_DEVICE_GET_CLASS(obj) \
71         OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
72 #define VIRTIO_DEVICE_CLASS(klass) \
73         OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
74 #define VIRTIO_DEVICE(obj) \
75         OBJECT_CHECK(VirtIODevice, (obj), TYPE_VIRTIO_DEVICE)
76 
77 enum virtio_device_endian {
78     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
79     VIRTIO_DEVICE_ENDIAN_LITTLE,
80     VIRTIO_DEVICE_ENDIAN_BIG,
81 };
82 
83 struct VirtIODevice
84 {
85     DeviceState parent_obj;
86     const char *name;
87     uint8_t status;
88     uint8_t isr;
89     uint16_t queue_sel;
90     uint64_t guest_features;
91     uint64_t host_features;
92     uint64_t backend_features;
93     size_t config_len;
94     void *config;
95     uint16_t config_vector;
96     uint32_t generation;
97     int nvectors;
98     VirtQueue *vq;
99     MemoryListener listener;
100     uint16_t device_id;
101     bool vm_running;
102     bool broken; /* device in invalid state, needs reset */
103     bool use_started;
104     bool started;
105     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
106     VMChangeStateEntry *vmstate;
107     char *bus_name;
108     uint8_t device_endian;
109     bool use_guest_notifier_mask;
110     AddressSpace *dma_as;
111     QLIST_HEAD(, VirtQueue) *vector_queues;
112 };
113 
114 typedef struct VirtioDeviceClass {
115     /*< private >*/
116     DeviceClass parent;
117     /*< public >*/
118 
119     /* This is what a VirtioDevice must implement */
120     DeviceRealize realize;
121     DeviceUnrealize unrealize;
122     uint64_t (*get_features)(VirtIODevice *vdev,
123                              uint64_t requested_features,
124                              Error **errp);
125     uint64_t (*bad_features)(VirtIODevice *vdev);
126     void (*set_features)(VirtIODevice *vdev, uint64_t val);
127     int (*validate_features)(VirtIODevice *vdev);
128     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
129     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
130     void (*reset)(VirtIODevice *vdev);
131     void (*set_status)(VirtIODevice *vdev, uint8_t val);
132     /* For transitional devices, this is a bitmap of features
133      * that are only exposed on the legacy interface but not
134      * the modern one.
135      */
136     uint64_t legacy_features;
137     /* Test and clear event pending status.
138      * Should be called after unmask to avoid losing events.
139      * If backend does not support masking,
140      * must check in frontend instead.
141      */
142     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
143     /* Mask/unmask events from this vq. Any events reported
144      * while masked will become pending.
145      * If backend does not support masking,
146      * must mask in frontend instead.
147      */
148     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
149     int (*start_ioeventfd)(VirtIODevice *vdev);
150     void (*stop_ioeventfd)(VirtIODevice *vdev);
151     /* Saving and loading of a device; trying to deprecate save/load
152      * use vmsd for new devices.
153      */
154     void (*save)(VirtIODevice *vdev, QEMUFile *f);
155     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
156     /* Post load hook in vmsd is called early while device is processed, and
157      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
158      * unless they specifically want to verify the migration stream as it's
159      * processed, e.g. for bounds checking.
160      */
161     int (*post_load)(VirtIODevice *vdev);
162     const VMStateDescription *vmsd;
163 } VirtioDeviceClass;
164 
165 void virtio_instance_init_common(Object *proxy_obj, void *data,
166                                  size_t vdev_size, const char *vdev_name);
167 
168 void virtio_init(VirtIODevice *vdev, const char *name,
169                          uint16_t device_id, size_t config_size);
170 void virtio_cleanup(VirtIODevice *vdev);
171 
172 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
173 
174 /* Set the child bus name. */
175 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
176 
177 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
178 typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
179 
180 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
181                             VirtIOHandleOutput handle_output);
182 
183 void virtio_del_queue(VirtIODevice *vdev, int n);
184 
185 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
186                     unsigned int len);
187 void virtqueue_flush(VirtQueue *vq, unsigned int count);
188 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
189                               unsigned int len);
190 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
191                      unsigned int len);
192 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
193 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
194                     unsigned int len, unsigned int idx);
195 
196 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
197 void *virtqueue_pop(VirtQueue *vq, size_t sz);
198 unsigned int virtqueue_drop_all(VirtQueue *vq);
199 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
200 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
201                                 VirtQueueElement *elem);
202 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
203                           unsigned int out_bytes);
204 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
205                                unsigned int *out_bytes,
206                                unsigned max_in_bytes, unsigned max_out_bytes);
207 
208 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
209 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
210 
211 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
212 
213 extern const VMStateInfo virtio_vmstate_info;
214 
215 #define VMSTATE_VIRTIO_DEVICE \
216     {                                         \
217         .name = "virtio",                     \
218         .info = &virtio_vmstate_info,         \
219         .flags = VMS_SINGLE,                  \
220     }
221 
222 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
223 
224 void virtio_notify_config(VirtIODevice *vdev);
225 
226 void virtio_queue_set_notification(VirtQueue *vq, int enable);
227 
228 int virtio_queue_ready(VirtQueue *vq);
229 
230 int virtio_queue_empty(VirtQueue *vq);
231 
232 /* Host binding interface.  */
233 
234 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
235 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
236 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
237 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
238 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
239 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
240 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
241 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
242 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
243 void virtio_config_modern_writeb(VirtIODevice *vdev,
244                                  uint32_t addr, uint32_t data);
245 void virtio_config_modern_writew(VirtIODevice *vdev,
246                                  uint32_t addr, uint32_t data);
247 void virtio_config_modern_writel(VirtIODevice *vdev,
248                                  uint32_t addr, uint32_t data);
249 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
250 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
251 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
252 int virtio_queue_get_num(VirtIODevice *vdev, int n);
253 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
254 int virtio_get_num_queues(VirtIODevice *vdev);
255 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
256                             hwaddr avail, hwaddr used);
257 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
258 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
259 void virtio_queue_notify(VirtIODevice *vdev, int n);
260 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
261 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
262 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
263                                       MemoryRegion *mr, bool assign);
264 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
265 void virtio_reset(void *opaque);
266 void virtio_update_irq(VirtIODevice *vdev);
267 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
268 
269 /* Base devices.  */
270 typedef struct VirtIOBlkConf VirtIOBlkConf;
271 struct virtio_net_conf;
272 typedef struct virtio_serial_conf virtio_serial_conf;
273 typedef struct virtio_input_conf virtio_input_conf;
274 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
275 typedef struct VirtIORNGConf VirtIORNGConf;
276 
277 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
278     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
279                       VIRTIO_RING_F_INDIRECT_DESC, true), \
280     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
281                       VIRTIO_RING_F_EVENT_IDX, true),     \
282     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
283                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
284     DEFINE_PROP_BIT64("any_layout", _state, _field, \
285                       VIRTIO_F_ANY_LAYOUT, true), \
286     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
287                       VIRTIO_F_IOMMU_PLATFORM, false), \
288     DEFINE_PROP_BIT64("packed", _state, _field, \
289                       VIRTIO_F_RING_PACKED, false)
290 
291 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
292 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
293 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
294 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
295 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
296 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
297 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
298 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
299 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
300                                      unsigned int idx);
301 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
302 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
303 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
304 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
305 uint16_t virtio_get_queue_index(VirtQueue *vq);
306 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
307 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
308                                                 bool with_irqfd);
309 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
310 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
311 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
312 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
313 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
314 void virtio_queue_host_notifier_read(EventNotifier *n);
315 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
316                                                 VirtIOHandleAIOOutput handle_output);
317 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
318 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
319 
320 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
321 {
322     assert(fbit < 64);
323     *features |= (1ULL << fbit);
324 }
325 
326 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
327 {
328     assert(fbit < 64);
329     *features &= ~(1ULL << fbit);
330 }
331 
332 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
333 {
334     assert(fbit < 64);
335     return !!(features & (1ULL << fbit));
336 }
337 
338 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
339                                            unsigned int fbit)
340 {
341     return virtio_has_feature(vdev->guest_features, fbit);
342 }
343 
344 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
345                                            unsigned int fbit)
346 {
347     return virtio_has_feature(vdev->host_features, fbit);
348 }
349 
350 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
351 {
352     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
353         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
354         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
355     }
356     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
357     return false;
358 }
359 
360 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
361 {
362     if (vdev->use_started) {
363         return vdev->started;
364     }
365 
366     return status & VIRTIO_CONFIG_S_DRIVER_OK;
367 }
368 
369 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
370 {
371     if (started) {
372         vdev->start_on_kick = false;
373     }
374 
375     if (vdev->use_started) {
376         vdev->started = started;
377     }
378 }
379 #endif
380