xref: /openbmc/qemu/include/hw/virtio/virtio.h (revision dfbd2768)
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 "hw/hw.h"
18 #include "net/net.h"
19 #include "hw/qdev.h"
20 #include "sysemu/sysemu.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 (addr + align - 1) & ~(align - 1);
38 }
39 
40 typedef struct VirtQueue VirtQueue;
41 
42 #define VIRTQUEUE_MAX_SIZE 1024
43 
44 typedef struct VirtQueueElement
45 {
46     unsigned int index;
47     unsigned int out_num;
48     unsigned int in_num;
49     hwaddr *in_addr;
50     hwaddr *out_addr;
51     struct iovec *in_sg;
52     struct iovec *out_sg;
53 } VirtQueueElement;
54 
55 #define VIRTIO_QUEUE_MAX 1024
56 
57 #define VIRTIO_NO_VECTOR 0xffff
58 
59 #define TYPE_VIRTIO_DEVICE "virtio-device"
60 #define VIRTIO_DEVICE_GET_CLASS(obj) \
61         OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
62 #define VIRTIO_DEVICE_CLASS(klass) \
63         OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
64 #define VIRTIO_DEVICE(obj) \
65         OBJECT_CHECK(VirtIODevice, (obj), TYPE_VIRTIO_DEVICE)
66 
67 enum virtio_device_endian {
68     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
69     VIRTIO_DEVICE_ENDIAN_LITTLE,
70     VIRTIO_DEVICE_ENDIAN_BIG,
71 };
72 
73 struct VirtIODevice
74 {
75     DeviceState parent_obj;
76     const char *name;
77     uint8_t status;
78     uint8_t isr;
79     uint16_t queue_sel;
80     uint64_t guest_features;
81     uint64_t host_features;
82     size_t config_len;
83     void *config;
84     uint16_t config_vector;
85     uint32_t generation;
86     int nvectors;
87     VirtQueue *vq;
88     uint16_t device_id;
89     bool vm_running;
90     bool broken; /* device in invalid state, needs reset */
91     VMChangeStateEntry *vmstate;
92     char *bus_name;
93     uint8_t device_endian;
94     bool use_guest_notifier_mask;
95     QLIST_HEAD(, VirtQueue) *vector_queues;
96 };
97 
98 typedef struct VirtioDeviceClass {
99     /*< private >*/
100     DeviceClass parent;
101     /*< public >*/
102 
103     /* This is what a VirtioDevice must implement */
104     DeviceRealize realize;
105     DeviceUnrealize unrealize;
106     uint64_t (*get_features)(VirtIODevice *vdev,
107                              uint64_t requested_features,
108                              Error **errp);
109     uint64_t (*bad_features)(VirtIODevice *vdev);
110     void (*set_features)(VirtIODevice *vdev, uint64_t val);
111     int (*validate_features)(VirtIODevice *vdev);
112     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
113     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
114     void (*reset)(VirtIODevice *vdev);
115     void (*set_status)(VirtIODevice *vdev, uint8_t val);
116     /* For transitional devices, this is a bitmap of features
117      * that are only exposed on the legacy interface but not
118      * the modern one.
119      */
120     uint64_t legacy_features;
121     /* Test and clear event pending status.
122      * Should be called after unmask to avoid losing events.
123      * If backend does not support masking,
124      * must check in frontend instead.
125      */
126     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
127     /* Mask/unmask events from this vq. Any events reported
128      * while masked will become pending.
129      * If backend does not support masking,
130      * must mask in frontend instead.
131      */
132     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
133     int (*start_ioeventfd)(VirtIODevice *vdev);
134     void (*stop_ioeventfd)(VirtIODevice *vdev);
135     /* Saving and loading of a device; trying to deprecate save/load
136      * use vmsd for new devices.
137      */
138     void (*save)(VirtIODevice *vdev, QEMUFile *f);
139     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
140     const VMStateDescription *vmsd;
141 } VirtioDeviceClass;
142 
143 void virtio_instance_init_common(Object *proxy_obj, void *data,
144                                  size_t vdev_size, const char *vdev_name);
145 
146 void virtio_init(VirtIODevice *vdev, const char *name,
147                          uint16_t device_id, size_t config_size);
148 void virtio_cleanup(VirtIODevice *vdev);
149 
150 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
151 
152 /* Set the child bus name. */
153 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
154 
155 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
156 
157 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
158                             VirtIOHandleOutput handle_output);
159 
160 void virtio_del_queue(VirtIODevice *vdev, int n);
161 
162 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
163                     unsigned int len);
164 void virtqueue_flush(VirtQueue *vq, unsigned int count);
165 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
166                               unsigned int len);
167 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
168                      unsigned int len);
169 bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
170 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
171                     unsigned int len, unsigned int idx);
172 
173 void virtqueue_map(VirtQueueElement *elem);
174 void *virtqueue_pop(VirtQueue *vq, size_t sz);
175 void *qemu_get_virtqueue_element(QEMUFile *f, size_t sz);
176 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem);
177 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
178                           unsigned int out_bytes);
179 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
180                                unsigned int *out_bytes,
181                                unsigned max_in_bytes, unsigned max_out_bytes);
182 
183 bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq);
184 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
185 
186 void virtio_save(VirtIODevice *vdev, QEMUFile *f);
187 
188 extern const VMStateInfo virtio_vmstate_info;
189 
190 #define VMSTATE_VIRTIO_DEVICE \
191     {                                         \
192         .name = "virtio",                     \
193         .info = &virtio_vmstate_info,         \
194         .flags = VMS_SINGLE,                  \
195     }
196 
197 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
198 
199 void virtio_notify_config(VirtIODevice *vdev);
200 
201 void virtio_queue_set_notification(VirtQueue *vq, int enable);
202 
203 int virtio_queue_ready(VirtQueue *vq);
204 
205 int virtio_queue_empty(VirtQueue *vq);
206 
207 /* Host binding interface.  */
208 
209 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
210 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
211 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
212 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
213 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
214 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
215 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
216 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
217 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
218 void virtio_config_modern_writeb(VirtIODevice *vdev,
219                                  uint32_t addr, uint32_t data);
220 void virtio_config_modern_writew(VirtIODevice *vdev,
221                                  uint32_t addr, uint32_t data);
222 void virtio_config_modern_writel(VirtIODevice *vdev,
223                                  uint32_t addr, uint32_t data);
224 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
225 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
226 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
227 int virtio_queue_get_num(VirtIODevice *vdev, int n);
228 int virtio_get_num_queues(VirtIODevice *vdev);
229 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
230                             hwaddr avail, hwaddr used);
231 void virtio_queue_update_rings(VirtIODevice *vdev, int n);
232 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
233 void virtio_queue_notify(VirtIODevice *vdev, int n);
234 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
235 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
236 int virtio_set_status(VirtIODevice *vdev, uint8_t val);
237 void virtio_reset(void *opaque);
238 void virtio_update_irq(VirtIODevice *vdev);
239 int virtio_set_features(VirtIODevice *vdev, uint64_t val);
240 
241 /* Base devices.  */
242 typedef struct VirtIOBlkConf VirtIOBlkConf;
243 struct virtio_net_conf;
244 typedef struct virtio_serial_conf virtio_serial_conf;
245 typedef struct virtio_input_conf virtio_input_conf;
246 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
247 typedef struct VirtIORNGConf VirtIORNGConf;
248 
249 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
250     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
251                       VIRTIO_RING_F_INDIRECT_DESC, true), \
252     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
253                       VIRTIO_RING_F_EVENT_IDX, true),     \
254     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
255                       VIRTIO_F_NOTIFY_ON_EMPTY, true), \
256     DEFINE_PROP_BIT64("any_layout", _state, _field, \
257                       VIRTIO_F_ANY_LAYOUT, true)
258 
259 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
260 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
261 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
262 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
263 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
264 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
265 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
266 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
267 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
268 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
269 uint16_t virtio_get_queue_index(VirtQueue *vq);
270 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
271 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
272                                                 bool with_irqfd);
273 int virtio_device_start_ioeventfd(VirtIODevice *vdev);
274 void virtio_device_stop_ioeventfd(VirtIODevice *vdev);
275 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
276 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
277 void virtio_queue_host_notifier_read(EventNotifier *n);
278 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
279                                                 void (*fn)(VirtIODevice *,
280                                                            VirtQueue *));
281 void virtio_irq(VirtQueue *vq);
282 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
283 VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
284 
285 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
286 {
287     assert(fbit < 64);
288     *features |= (1ULL << fbit);
289 }
290 
291 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
292 {
293     assert(fbit < 64);
294     *features &= ~(1ULL << fbit);
295 }
296 
297 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
298 {
299     assert(fbit < 64);
300     return !!(features & (1ULL << fbit));
301 }
302 
303 static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
304                                            unsigned int fbit)
305 {
306     return virtio_has_feature(vdev->guest_features, fbit);
307 }
308 
309 static inline bool virtio_host_has_feature(VirtIODevice *vdev,
310                                            unsigned int fbit)
311 {
312     return virtio_has_feature(vdev->host_features, fbit);
313 }
314 
315 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
316 {
317     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
318         assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
319         return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
320     }
321     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
322     return false;
323 }
324 #endif
325