xref: /openbmc/qemu/include/hw/virtio/virtio.h (revision d4842052100a3b44167e34ebdce0e7b3bf7512cf)
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/hw.h"
19 #include "net/net.h"
20 #include "hw/qdev.h"
21 #include "sysemu/sysemu.h"
22 #include "migration/vmstate.h"
23 #include "qemu/event_notifier.h"
24 #include "standard-headers/linux/virtio_config.h"
25 #include "standard-headers/linux/virtio_ring.h"
26 
27 /* A guest should never accept this.  It implies negotiation is broken. */
28 #define VIRTIO_F_BAD_FEATURE		30
29 
30 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \
31                                 (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
32                                 (0x1ULL << VIRTIO_F_ANY_LAYOUT))
33 
34 struct VirtQueue;
35 
36 static inline hwaddr vring_align(hwaddr addr,
37                                              unsigned long align)
38 {
39     return QEMU_ALIGN_UP(addr, align);
40 }
41 
42 /*
43  * Calculate the number of bytes up to and including the given 'field' of
44  * 'container'.
45  */
46 #define virtio_endof(container, field) \
47     (offsetof(container, field) + sizeof_field(container, field))
48 
49 typedef struct VirtIOFeature {
50     uint64_t flags;
51     size_t end;
52 } VirtIOFeature;
53 
54 size_t virtio_feature_get_config_size(VirtIOFeature *features,
55                                       uint64_t host_features);
56 
57 typedef struct VirtQueue VirtQueue;
58 
59 #define VIRTQUEUE_MAX_SIZE 1024
60 
61 typedef struct VirtQueueElement
62 {
63     unsigned int index;
64     unsigned int out_num;
65     unsigned int in_num;
66     hwaddr *in_addr;
67     hwaddr *out_addr;
68     struct iovec *in_sg;
69     struct iovec *out_sg;
70 } VirtQueueElement;
71 
72 #define VIRTIO_QUEUE_MAX 1024
73 
74 #define VIRTIO_NO_VECTOR 0xffff
75 
76 #define TYPE_VIRTIO_DEVICE "virtio-device"
77 #define VIRTIO_DEVICE_GET_CLASS(obj) \
78         OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
79 #define VIRTIO_DEVICE_CLASS(klass) \
80         OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
81 #define VIRTIO_DEVICE(obj) \
82         OBJECT_CHECK(VirtIODevice, (obj), TYPE_VIRTIO_DEVICE)
83 
84 enum virtio_device_endian {
85     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
86     VIRTIO_DEVICE_ENDIAN_LITTLE,
87     VIRTIO_DEVICE_ENDIAN_BIG,
88 };
89 
90 struct VirtIODevice
91 {
92     DeviceState parent_obj;
93     const char *name;
94     uint8_t status;
95     uint8_t isr;
96     uint16_t queue_sel;
97     uint64_t guest_features;
98     uint64_t host_features;
99     uint64_t backend_features;
100     size_t config_len;
101     void *config;
102     uint16_t config_vector;
103     uint32_t generation;
104     int nvectors;
105     VirtQueue *vq;
106     MemoryListener listener;
107     uint16_t device_id;
108     bool vm_running;
109     bool broken; /* device in invalid state, needs reset */
110     bool use_started;
111     bool started;
112     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
113     VMChangeStateEntry *vmstate;
114     char *bus_name;
115     uint8_t device_endian;
116     bool use_guest_notifier_mask;
117     AddressSpace *dma_as;
118     QLIST_HEAD(, VirtQueue) *vector_queues;
119 };
120 
121 typedef struct VirtioDeviceClass {
122     /*< private >*/
123     DeviceClass parent;
124     /*< public >*/
125 
126     /* This is what a VirtioDevice must implement */
127     DeviceRealize realize;
128     DeviceUnrealize unrealize;
129     uint64_t (*get_features)(VirtIODevice *vdev,
130                              uint64_t requested_features,
131                              Error **errp);
132     uint64_t (*bad_features)(VirtIODevice *vdev);
133     void (*set_features)(VirtIODevice *vdev, uint64_t val);
134     int (*validate_features)(VirtIODevice *vdev);
135     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
136     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
137     void (*reset)(VirtIODevice *vdev);
138     void (*set_status)(VirtIODevice *vdev, uint8_t val);
139     /* For transitional devices, this is a bitmap of features
140      * that are only exposed on the legacy interface but not
141      * the modern one.
142      */
143     uint64_t legacy_features;
144     /* Test and clear event pending status.
145      * Should be called after unmask to avoid losing events.
146      * If backend does not support masking,
147      * must check in frontend instead.
148      */
149     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
150     /* Mask/unmask events from this vq. Any events reported
151      * while masked will become pending.
152      * If backend does not support masking,
153      * must mask in frontend instead.
154      */
155     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
156     int (*start_ioeventfd)(VirtIODevice *vdev);
157     void (*stop_ioeventfd)(VirtIODevice *vdev);
158     /* Saving and loading of a device; trying to deprecate save/load
159      * use vmsd for new devices.
160      */
161     void (*save)(VirtIODevice *vdev, QEMUFile *f);
162     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
163     const VMStateDescription *vmsd;
164 } VirtioDeviceClass;
165 
166 void virtio_instance_init_common(Object *proxy_obj, void *data,
167                                  size_t vdev_size, const char *vdev_name);
168 
169 void virtio_init(VirtIODevice *vdev, const char *name,
170                          uint16_t device_id, size_t config_size);
171 void virtio_cleanup(VirtIODevice *vdev);
172 
173 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
174 
175 /* Set the child bus name. */
176 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
177 
178 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
179 typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
180 
181 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
182                             VirtIOHandleOutput handle_output);
183 
184 void virtio_del_queue(VirtIODevice *vdev, int n);
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(QEMUFile *f, 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 
289 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
290 bool virtio_queue_enabled(VirtIODevice *vdev, int n);
291 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
292 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
293 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
294 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
295 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
296 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
297 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
298 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
299 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
300 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
301 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
302 uint16_t virtio_get_queue_index(VirtQueue *vq);
303 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
304 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
305                                                 bool with_irqfd);
306 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
307 void virtio_device_stop_ioeventfd(VirtIODevice *vdev);
308 int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
309 void virtio_device_release_ioeventfd(VirtIODevice *vdev);
310 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
311 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
312 void virtio_queue_host_notifier_read(EventNotifier *n);
313 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
314                                                 VirtIOHandleAIOOutput handle_output);
315 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
316 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
317 
318 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
319 {
320     assert(fbit < 64);
321     *features |= (1ULL << fbit);
322 }
323 
324 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
325 {
326     assert(fbit < 64);
327     *features &= ~(1ULL << fbit);
328 }
329 
330 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
331 {
332     assert(fbit < 64);
333     return !!(features & (1ULL << fbit));
334 }
335 
336 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
337                                            unsigned int fbit)
338 {
339     return virtio_has_feature(vdev->guest_features, fbit);
340 }
341 
342 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
343                                            unsigned int fbit)
344 {
345     return virtio_has_feature(vdev->host_features, fbit);
346 }
347 
348 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
349 {
350     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
351         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
352         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
353     }
354     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
355     return false;
356 }
357 
358 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
359 {
360     if (vdev->use_started) {
361         return vdev->started;
362     }
363 
364     return status & VIRTIO_CONFIG_S_DRIVER_OK;
365 }
366 
367 static inline void virtio_set_started(VirtIODevice *vdev, bool started)
368 {
369     if (started) {
370         vdev->start_on_kick = false;
371     }
372 
373     if (vdev->use_started) {
374         vdev->started = started;
375     }
376 }
377 #endif
378