xref: /openbmc/qemu/include/hw/virtio/virtio.h (revision a489d195)
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 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE)
72 
73 enum virtio_device_endian {
74     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
75     VIRTIO_DEVICE_ENDIAN_LITTLE,
76     VIRTIO_DEVICE_ENDIAN_BIG,
77 };
78 
79 struct VirtIODevice
80 {
81     DeviceState parent_obj;
82     const char *name;
83     uint8_t status;
84     uint8_t isr;
85     uint16_t queue_sel;
86     uint64_t guest_features;
87     uint64_t host_features;
88     uint64_t backend_features;
89     size_t config_len;
90     void *config;
91     uint16_t config_vector;
92     uint32_t generation;
93     int nvectors;
94     VirtQueue *vq;
95     MemoryListener listener;
96     uint16_t device_id;
97     bool vm_running;
98     bool broken; /* device in invalid state, needs reset */
99     bool use_disabled_flag; /* allow use of 'disable' flag when needed */
100     bool disabled; /* device in temporarily disabled state */
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 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     /* Post load hook in vmsd is called early while device is processed, and
155      * when VirtIODevice isn't fully initialized.  Devices should use this instead,
156      * unless they specifically want to verify the migration stream as it's
157      * processed, e.g. for bounds checking.
158      */
159     int (*post_load)(VirtIODevice *vdev);
160     const VMStateDescription *vmsd;
161     bool (*primary_unplug_pending)(void *opaque);
162 };
163 
164 void virtio_instance_init_common(Object *proxy_obj, void *data,
165                                  size_t vdev_size, const char *vdev_name);
166 
167 void virtio_init(VirtIODevice *vdev, const char *name,
168                          uint16_t device_id, size_t config_size);
169 void virtio_cleanup(VirtIODevice *vdev);
170 
171 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
172 
173 /* Set the child bus name. */
174 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
175 
176 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
177 typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
178 
179 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
180                             VirtIOHandleOutput handle_output);
181 
182 void virtio_del_queue(VirtIODevice *vdev, int n);
183 
184 void virtio_delete_queue(VirtQueue *vq);
185 
186 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
187                     unsigned int len);
188 void virtqueue_flush(VirtQueue *vq, unsigned int count);
189 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
190                               unsigned int len);
191 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
192                      unsigned int len);
193 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
194 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
195                     unsigned int len, unsigned int idx);
196 
197 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
198 void *virtqueue_pop(VirtQueue *vq, size_t sz);
199 unsigned int virtqueue_drop_all(VirtQueue *vq);
200 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
201 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
202                                 VirtQueueElement *elem);
203 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
204                           unsigned int out_bytes);
205 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
206                                unsigned int *out_bytes,
207                                unsigned max_in_bytes, unsigned max_out_bytes);
208 
209 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
210 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
211 
212 int virtio_save(VirtIODevice *vdev, QEMUFile *f);
213 
214 extern const VMStateInfo virtio_vmstate_info;
215 
216 #define VMSTATE_VIRTIO_DEVICE \
217     {                                         \
218         .name = "virtio",                     \
219         .info = &virtio_vmstate_info,         \
220         .flags = VMS_SINGLE,                  \
221     }
222 
223 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
224 
225 void virtio_notify_config(VirtIODevice *vdev);
226 
227 bool virtio_queue_get_notification(VirtQueue *vq);
228 void virtio_queue_set_notification(VirtQueue *vq, int enable);
229 
230 int virtio_queue_ready(VirtQueue *vq);
231 
232 int virtio_queue_empty(VirtQueue *vq);
233 
234 /* Host binding interface.  */
235 
236 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
237 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
238 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
239 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
240 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
241 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
242 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
243 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
244 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
245 void virtio_config_modern_writeb(VirtIODevice *vdev,
246                                  uint32_t addr, uint32_t data);
247 void virtio_config_modern_writew(VirtIODevice *vdev,
248                                  uint32_t addr, uint32_t data);
249 void virtio_config_modern_writel(VirtIODevice *vdev,
250                                  uint32_t addr, uint32_t data);
251 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
252 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
253 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
254 int virtio_queue_get_num(VirtIODevice *vdev, int n);
255 int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
256 int virtio_get_num_queues(VirtIODevice *vdev);
257 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
258                             hwaddr avail, hwaddr used);
259 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
260 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
261 void virtio_queue_notify(VirtIODevice *vdev, int n);
262 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
263 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
264 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
265                                       MemoryRegion *mr, bool assign);
266 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
267 void virtio_reset(void *opaque);
268 void virtio_update_irq(VirtIODevice *vdev);
269 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
270 
271 /* Base devices.  */
272 typedef struct VirtIOBlkConf VirtIOBlkConf;
273 struct virtio_net_conf;
274 typedef struct virtio_serial_conf virtio_serial_conf;
275 typedef struct virtio_input_conf virtio_input_conf;
276 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
277 typedef struct VirtIORNGConf VirtIORNGConf;
278 
279 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
280     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
281                       VIRTIO_RING_F_INDIRECT_DESC, true), \
282     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
283                       VIRTIO_RING_F_EVENT_IDX, true),     \
284     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
285                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
286     DEFINE_PROP_BIT64("any_layout", _state, _field, \
287                       VIRTIO_F_ANY_LAYOUT, true), \
288     DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
289                       VIRTIO_F_IOMMU_PLATFORM, false), \
290     DEFINE_PROP_BIT64("packed", _state, _field, \
291                       VIRTIO_F_RING_PACKED, false)
292 
293 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
294 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
295 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
296 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
297 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
298 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
299 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
300 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
301 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
302 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
303                                      unsigned int idx);
304 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
305 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
306 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
307 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
308 uint16_t virtio_get_queue_index(VirtQueue *vq);
309 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
310 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
311                                                 bool with_irqfd);
312 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
313 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
314 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
315 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
316 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
317 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
318 void virtio_queue_host_notifier_read(EventNotifier *n);
319 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
320                                                 VirtIOHandleAIOOutput handle_output);
321 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
322 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
323 
324 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
325 {
326     assert(fbit < 64);
327     *features |= (1ULL << fbit);
328 }
329 
330 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
331 {
332     assert(fbit < 64);
333     *features &= ~(1ULL << fbit);
334 }
335 
336 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
337 {
338     assert(fbit < 64);
339     return !!(features & (1ULL << fbit));
340 }
341 
342 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
343                                            unsigned int fbit)
344 {
345     return virtio_has_feature(vdev->guest_features, fbit);
346 }
347 
348 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
349                                            unsigned int fbit)
350 {
351     return virtio_has_feature(vdev->host_features, fbit);
352 }
353 
354 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
355 {
356     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
357         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
358         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
359     }
360     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
361     return false;
362 }
363 
364 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
365 {
366     if (vdev->use_started) {
367         return vdev->started;
368     }
369 
370     return status & VIRTIO_CONFIG_S_DRIVER_OK;
371 }
372 
373 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
374 {
375     if (started) {
376         vdev->start_on_kick = false;
377     }
378 
379     if (vdev->use_started) {
380         vdev->started = started;
381     }
382 }
383 
384 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
385 {
386     if (vdev->use_disabled_flag) {
387         vdev->disabled = disable;
388     }
389 }
390 
391 static inline bool virtio_device_disabled(VirtIODevice *vdev)
392 {
393     return unlikely(vdev->disabled || vdev->broken);
394 }
395 
396 bool virtio_legacy_allowed(VirtIODevice *vdev);
397 
398 #endif
399