xref: /qemu/include/hw/virtio/virtio.h (revision 5d5b33c08031cfe0e9872bde1f9dcb2215f9b30a)
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 out_num;
56     unsigned int in_num;
57     hwaddr *in_addr;
58     hwaddr *out_addr;
59     struct iovec *in_sg;
60     struct iovec *out_sg;
61 } VirtQueueElement;
62 
63 #define VIRTIO_QUEUE_MAX 1024
64 
65 #define VIRTIO_NO_VECTOR 0xffff
66 
67 #define TYPE_VIRTIO_DEVICE "virtio-device"
68 #define VIRTIO_DEVICE_GET_CLASS(obj) \
69         OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
70 #define VIRTIO_DEVICE_CLASS(klass) \
71         OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
72 #define VIRTIO_DEVICE(obj) \
73         OBJECT_CHECK(VirtIODevice, (obj), TYPE_VIRTIO_DEVICE)
74 
75 enum virtio_device_endian {
76     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
77     VIRTIO_DEVICE_ENDIAN_LITTLE,
78     VIRTIO_DEVICE_ENDIAN_BIG,
79 };
80 
81 struct VirtIODevice
82 {
83     DeviceState parent_obj;
84     const char *name;
85     uint8_t status;
86     uint8_t isr;
87     uint16_t queue_sel;
88     uint64_t guest_features;
89     uint64_t host_features;
90     uint64_t backend_features;
91     size_t config_len;
92     void *config;
93     uint16_t config_vector;
94     uint32_t generation;
95     int nvectors;
96     VirtQueue *vq;
97     MemoryListener listener;
98     uint16_t device_id;
99     bool vm_running;
100     bool broken; /* device in invalid state, needs reset */
101     bool use_started;
102     bool started;
103     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
104     VMChangeStateEntry *vmstate;
105     char *bus_name;
106     uint8_t device_endian;
107     bool use_guest_notifier_mask;
108     AddressSpace *dma_as;
109     QLIST_HEAD(, VirtQueue) *vector_queues;
110 };
111 
112 typedef struct VirtioDeviceClass {
113     /*< private >*/
114     DeviceClass parent;
115     /*< public >*/
116 
117     /* This is what a VirtioDevice must implement */
118     DeviceRealize realize;
119     DeviceUnrealize unrealize;
120     uint64_t (*get_features)(VirtIODevice *vdev,
121                              uint64_t requested_features,
122                              Error **errp);
123     uint64_t (*bad_features)(VirtIODevice *vdev);
124     void (*set_features)(VirtIODevice *vdev, uint64_t val);
125     int (*validate_features)(VirtIODevice *vdev);
126     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
127     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
128     void (*reset)(VirtIODevice *vdev);
129     void (*set_status)(VirtIODevice *vdev, uint8_t val);
130     /* For transitional devices, this is a bitmap of features
131      * that are only exposed on the legacy interface but not
132      * the modern one.
133      */
134     uint64_t legacy_features;
135     /* Test and clear event pending status.
136      * Should be called after unmask to avoid losing events.
137      * If backend does not support masking,
138      * must check in frontend instead.
139      */
140     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
141     /* Mask/unmask events from this vq. Any events reported
142      * while masked will become pending.
143      * If backend does not support masking,
144      * must mask in frontend instead.
145      */
146     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
147     int (*start_ioeventfd)(VirtIODevice *vdev);
148     void (*stop_ioeventfd)(VirtIODevice *vdev);
149     /* Saving and loading of a device; trying to deprecate save/load
150      * use vmsd for new devices.
151      */
152     void (*save)(VirtIODevice *vdev, QEMUFile *f);
153     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
154     const VMStateDescription *vmsd;
155 } VirtioDeviceClass;
156 
157 void virtio_instance_init_common(Object *proxy_obj, void *data,
158                                  size_t vdev_size, const char *vdev_name);
159 
160 void virtio_init(VirtIODevice *vdev, const char *name,
161                          uint16_t device_id, size_t config_size);
162 void virtio_cleanup(VirtIODevice *vdev);
163 
164 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
165 
166 /* Set the child bus name. */
167 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
168 
169 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
170 typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
171 
172 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
173                             VirtIOHandleOutput handle_output);
174 
175 void virtio_del_queue(VirtIODevice *vdev, int n);
176 
177 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
178                     unsigned int len);
179 void virtqueue_flush(VirtQueue *vq, unsigned int count);
180 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
181                               unsigned int len);
182 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
183                      unsigned int len);
184 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
185 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
186                     unsigned int len, unsigned int idx);
187 
188 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
189 void *virtqueue_pop(VirtQueue *vq, size_t sz);
190 unsigned int virtqueue_drop_all(VirtQueue *vq);
191 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
192 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem);
193 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
194                           unsigned int out_bytes);
195 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
196                                unsigned int *out_bytes,
197                                unsigned max_in_bytes, unsigned max_out_bytes);
198 
199 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
200 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
201 
202 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
203 
204 extern const VMStateInfo virtio_vmstate_info;
205 
206 #define VMSTATE_VIRTIO_DEVICE \
207     {                                         \
208         .name = "virtio",                     \
209         .info = &virtio_vmstate_info,         \
210         .flags = VMS_SINGLE,                  \
211     }
212 
213 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
214 
215 void virtio_notify_config(VirtIODevice *vdev);
216 
217 void virtio_queue_set_notification(VirtQueue *vq, int enable);
218 
219 int virtio_queue_ready(VirtQueue *vq);
220 
221 int virtio_queue_empty(VirtQueue *vq);
222 
223 /* Host binding interface.  */
224 
225 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
226 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
227 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
228 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
229 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
230 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
231 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
232 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
233 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
234 void virtio_config_modern_writeb(VirtIODevice *vdev,
235                                  uint32_t addr, uint32_t data);
236 void virtio_config_modern_writew(VirtIODevice *vdev,
237                                  uint32_t addr, uint32_t data);
238 void virtio_config_modern_writel(VirtIODevice *vdev,
239                                  uint32_t addr, uint32_t data);
240 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
241 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
242 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
243 int virtio_queue_get_num(VirtIODevice *vdev, int n);
244 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
245 int virtio_get_num_queues(VirtIODevice *vdev);
246 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
247                             hwaddr avail, hwaddr used);
248 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
249 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
250 void virtio_queue_notify(VirtIODevice *vdev, int n);
251 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
252 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
253 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
254                                       MemoryRegion *mr, bool assign);
255 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
256 void virtio_reset(void *opaque);
257 void virtio_update_irq(VirtIODevice *vdev);
258 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
259 
260 /* Base devices.  */
261 typedef struct VirtIOBlkConf VirtIOBlkConf;
262 struct virtio_net_conf;
263 typedef struct virtio_serial_conf virtio_serial_conf;
264 typedef struct virtio_input_conf virtio_input_conf;
265 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
266 typedef struct VirtIORNGConf VirtIORNGConf;
267 
268 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
269     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
270                       VIRTIO_RING_F_INDIRECT_DESC, true), \
271     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
272                       VIRTIO_RING_F_EVENT_IDX, true),     \
273     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
274                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
275     DEFINE_PROP_BIT64("any_layout", _state, _field, \
276                       VIRTIO_F_ANY_LAYOUT, true), \
277     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
278                       VIRTIO_F_IOMMU_PLATFORM, false)
279 
280 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
281 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
282 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
283 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
284 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
285 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
286 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
287 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
288 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
289 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
290 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
291 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
292 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
293 uint16_t virtio_get_queue_index(VirtQueue *vq);
294 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
295 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
296                                                 bool with_irqfd);
297 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
298 void virtio_device_stop_ioeventfd(VirtIODevice *vdev);
299 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
300 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
301 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
302 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
303 void virtio_queue_host_notifier_read(EventNotifier *n);
304 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
305                                                 VirtIOHandleAIOOutput handle_output);
306 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
307 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
308 
309 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
310 {
311     assert(fbit < 64);
312     *features |= (1ULL << fbit);
313 }
314 
315 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
316 {
317     assert(fbit < 64);
318     *features &= ~(1ULL << fbit);
319 }
320 
321 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
322 {
323     assert(fbit < 64);
324     return !!(features & (1ULL << fbit));
325 }
326 
327 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
328                                            unsigned int fbit)
329 {
330     return virtio_has_feature(vdev->guest_features, fbit);
331 }
332 
333 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
334                                            unsigned int fbit)
335 {
336     return virtio_has_feature(vdev->host_features, fbit);
337 }
338 
339 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
340 {
341     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
342         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
343         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
344     }
345     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
346     return false;
347 }
348 
349 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
350 {
351     if (vdev->use_started) {
352         return vdev->started;
353     }
354 
355     return status & VIRTIO_CONFIG_S_DRIVER_OK;
356 }
357 
358 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
359 {
360     if (started) {
361         vdev->start_on_kick = false;
362     }
363 
364     if (vdev->use_started) {
365         vdev->started = started;
366     }
367 }
368 #endif
369