xref: /openbmc/qemu/include/hw/virtio/virtio.h (revision a9a5c473)
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_disabled_flag; /* allow use of 'disable' flag when needed */
104     bool disabled; /* device in temporarily disabled state */
105     bool use_started;
106     bool started;
107     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
108     VMChangeStateEntry *vmstate;
109     char *bus_name;
110     uint8_t device_endian;
111     bool use_guest_notifier_mask;
112     AddressSpace *dma_as;
113     QLIST_HEAD(, VirtQueue) *vector_queues;
114 };
115 
116 typedef struct VirtioDeviceClass {
117     /*< private >*/
118     DeviceClass parent;
119     /*< public >*/
120 
121     /* This is what a VirtioDevice must implement */
122     DeviceRealize realize;
123     DeviceUnrealize unrealize;
124     uint64_t (*get_features)(VirtIODevice *vdev,
125                              uint64_t requested_features,
126                              Error **errp);
127     uint64_t (*bad_features)(VirtIODevice *vdev);
128     void (*set_features)(VirtIODevice *vdev, uint64_t val);
129     int (*validate_features)(VirtIODevice *vdev);
130     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
131     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
132     void (*reset)(VirtIODevice *vdev);
133     void (*set_status)(VirtIODevice *vdev, uint8_t val);
134     /* For transitional devices, this is a bitmap of features
135      * that are only exposed on the legacy interface but not
136      * the modern one.
137      */
138     uint64_t legacy_features;
139     /* Test and clear event pending status.
140      * Should be called after unmask to avoid losing events.
141      * If backend does not support masking,
142      * must check in frontend instead.
143      */
144     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
145     /* Mask/unmask events from this vq. Any events reported
146      * while masked will become pending.
147      * If backend does not support masking,
148      * must mask in frontend instead.
149      */
150     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
151     int (*start_ioeventfd)(VirtIODevice *vdev);
152     void (*stop_ioeventfd)(VirtIODevice *vdev);
153     /* Saving and loading of a device; trying to deprecate save/load
154      * use vmsd for new devices.
155      */
156     void (*save)(VirtIODevice *vdev, QEMUFile *f);
157     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
158     /* Post load hook in vmsd is called early while device is processed, and
159      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
160      * unless they specifically want to verify the migration stream as it's
161      * processed, e.g. for bounds checking.
162      */
163     int (*post_load)(VirtIODevice *vdev);
164     const VMStateDescription *vmsd;
165     bool (*primary_unplug_pending)(void *opaque);
166 } VirtioDeviceClass;
167 
168 void virtio_instance_init_common(Object *proxy_obj, void *data,
169                                  size_t vdev_size, const char *vdev_name);
170 
171 void virtio_init(VirtIODevice *vdev, const char *name,
172                          uint16_t device_id, size_t config_size);
173 void virtio_cleanup(VirtIODevice *vdev);
174 
175 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
176 
177 /* Set the child bus name. */
178 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
179 
180 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
181 typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
182 
183 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
184                             VirtIOHandleOutput handle_output);
185 
186 void virtio_del_queue(VirtIODevice *vdev, int n);
187 
188 void virtio_delete_queue(VirtQueue *vq);
189 
190 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
191                     unsigned int len);
192 void virtqueue_flush(VirtQueue *vq, unsigned int count);
193 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
194                               unsigned int len);
195 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
196                      unsigned int len);
197 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
198 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
199                     unsigned int len, unsigned int idx);
200 
201 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
202 void *virtqueue_pop(VirtQueue *vq, size_t sz);
203 unsigned int virtqueue_drop_all(VirtQueue *vq);
204 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
205 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
206                                 VirtQueueElement *elem);
207 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
208                           unsigned int out_bytes);
209 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
210                                unsigned int *out_bytes,
211                                unsigned max_in_bytes, unsigned max_out_bytes);
212 
213 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
214 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
215 
216 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
217 
218 extern const VMStateInfo virtio_vmstate_info;
219 
220 #define VMSTATE_VIRTIO_DEVICE \
221     {                                         \
222         .name = "virtio",                     \
223         .info = &virtio_vmstate_info,         \
224         .flags = VMS_SINGLE,                  \
225     }
226 
227 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
228 
229 void virtio_notify_config(VirtIODevice *vdev);
230 
231 bool virtio_queue_get_notification(VirtQueue *vq);
232 void virtio_queue_set_notification(VirtQueue *vq, int enable);
233 
234 int virtio_queue_ready(VirtQueue *vq);
235 
236 int virtio_queue_empty(VirtQueue *vq);
237 
238 /* Host binding interface.  */
239 
240 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
241 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
242 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
243 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
244 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
245 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
246 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
247 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
248 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
249 void virtio_config_modern_writeb(VirtIODevice *vdev,
250                                  uint32_t addr, uint32_t data);
251 void virtio_config_modern_writew(VirtIODevice *vdev,
252                                  uint32_t addr, uint32_t data);
253 void virtio_config_modern_writel(VirtIODevice *vdev,
254                                  uint32_t addr, uint32_t data);
255 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
256 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
257 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
258 int virtio_queue_get_num(VirtIODevice *vdev, int n);
259 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
260 int virtio_get_num_queues(VirtIODevice *vdev);
261 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
262                             hwaddr avail, hwaddr used);
263 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
264 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
265 void virtio_queue_notify(VirtIODevice *vdev, int n);
266 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
267 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
268 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
269                                       MemoryRegion *mr, bool assign);
270 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
271 void virtio_reset(void *opaque);
272 void virtio_update_irq(VirtIODevice *vdev);
273 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
274 
275 /* Base devices.  */
276 typedef struct VirtIOBlkConf VirtIOBlkConf;
277 struct virtio_net_conf;
278 typedef struct virtio_serial_conf virtio_serial_conf;
279 typedef struct virtio_input_conf virtio_input_conf;
280 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
281 typedef struct VirtIORNGConf VirtIORNGConf;
282 
283 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
284     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
285                       VIRTIO_RING_F_INDIRECT_DESC, true), \
286     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
287                       VIRTIO_RING_F_EVENT_IDX, true),     \
288     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
289                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
290     DEFINE_PROP_BIT64("any_layout", _state, _field, \
291                       VIRTIO_F_ANY_LAYOUT, true), \
292     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
293                       VIRTIO_F_IOMMU_PLATFORM, false), \
294     DEFINE_PROP_BIT64("packed", _state, _field, \
295                       VIRTIO_F_RING_PACKED, false)
296 
297 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
298 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
299 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
300 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
301 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
302 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
303 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
304 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
305 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
306                                      unsigned int idx);
307 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
308 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
309 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
310 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
311 uint16_t virtio_get_queue_index(VirtQueue *vq);
312 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
313 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
314                                                 bool with_irqfd);
315 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
316 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
317 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
318 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
319 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
320 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
321 void virtio_queue_host_notifier_read(EventNotifier *n);
322 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
323                                                 VirtIOHandleAIOOutput handle_output);
324 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
325 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
326 
327 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
328 {
329     assert(fbit < 64);
330     *features |= (1ULL << fbit);
331 }
332 
333 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
334 {
335     assert(fbit < 64);
336     *features &= ~(1ULL << fbit);
337 }
338 
339 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
340 {
341     assert(fbit < 64);
342     return !!(features & (1ULL << fbit));
343 }
344 
345 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
346                                            unsigned int fbit)
347 {
348     return virtio_has_feature(vdev->guest_features, fbit);
349 }
350 
351 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
352                                            unsigned int fbit)
353 {
354     return virtio_has_feature(vdev->host_features, fbit);
355 }
356 
357 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
358 {
359     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
360         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
361         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
362     }
363     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
364     return false;
365 }
366 
367 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
368 {
369     if (vdev->use_started) {
370         return vdev->started;
371     }
372 
373     return status & VIRTIO_CONFIG_S_DRIVER_OK;
374 }
375 
376 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
377 {
378     if (started) {
379         vdev->start_on_kick = false;
380     }
381 
382     if (vdev->use_started) {
383         vdev->started = started;
384     }
385 }
386 
387 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
388 {
389     if (vdev->use_disabled_flag) {
390         vdev->disabled = disable;
391     }
392 }
393 
394 static inline bool virtio_device_disabled(VirtIODevice *vdev)
395 {
396     return unlikely(vdev->disabled || vdev->broken);
397 }
398 
399 #endif
400