xref: /openbmc/qemu/include/hw/virtio/virtio.h (revision e0ab7fac)
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 #ifdef CONFIG_VIRTFS
23 #include "hw/virtio/virtio-9p.h"
24 #endif
25 
26 /* from Linux's linux/virtio_config.h */
27 
28 /* Status byte for guest to report progress, and synchronize features. */
29 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
30 #define VIRTIO_CONFIG_S_ACKNOWLEDGE     1
31 /* We have found a driver for the device. */
32 #define VIRTIO_CONFIG_S_DRIVER          2
33 /* Driver has used its parts of the config, and is happy */
34 #define VIRTIO_CONFIG_S_DRIVER_OK       4
35 /* We've given up on this device. */
36 #define VIRTIO_CONFIG_S_FAILED          0x80
37 
38 /* Some virtio feature bits (currently bits 28 through 31) are reserved for the
39  * transport being used (eg. virtio_ring), the rest are per-device feature bits. */
40 #define VIRTIO_TRANSPORT_F_START        28
41 #define VIRTIO_TRANSPORT_F_END          32
42 
43 /* We notify when the ring is completely used, even if the guest is suppressing
44  * callbacks */
45 #define VIRTIO_F_NOTIFY_ON_EMPTY        24
46 /* Can the device handle any descriptor layout? */
47 #define VIRTIO_F_ANY_LAYOUT             27
48 /* We support indirect buffer descriptors */
49 #define VIRTIO_RING_F_INDIRECT_DESC     28
50 /* The Guest publishes the used index for which it expects an interrupt
51  * at the end of the avail ring. Host should ignore the avail->flags field. */
52 /* The Host publishes the avail index for which it expects a kick
53  * at the end of the used ring. Guest should ignore the used->flags field. */
54 #define VIRTIO_RING_F_EVENT_IDX         29
55 /* A guest should never accept this.  It implies negotiation is broken. */
56 #define VIRTIO_F_BAD_FEATURE		30
57 
58 /* from Linux's linux/virtio_ring.h */
59 
60 /* This marks a buffer as continuing via the next field. */
61 #define VRING_DESC_F_NEXT       1
62 /* This marks a buffer as write-only (otherwise read-only). */
63 #define VRING_DESC_F_WRITE      2
64 /* This means the buffer contains a list of buffer descriptors. */
65 #define VRING_DESC_F_INDIRECT  4
66 
67 /* This means don't notify other side when buffer added. */
68 #define VRING_USED_F_NO_NOTIFY  1
69 /* This means don't interrupt guest when buffer consumed. */
70 #define VRING_AVAIL_F_NO_INTERRUPT      1
71 
72 struct VirtQueue;
73 
74 static inline hwaddr vring_align(hwaddr addr,
75                                              unsigned long align)
76 {
77     return (addr + align - 1) & ~(align - 1);
78 }
79 
80 typedef struct VirtQueue VirtQueue;
81 
82 #define VIRTQUEUE_MAX_SIZE 1024
83 
84 typedef struct VirtQueueElement
85 {
86     unsigned int index;
87     unsigned int out_num;
88     unsigned int in_num;
89     hwaddr in_addr[VIRTQUEUE_MAX_SIZE];
90     hwaddr out_addr[VIRTQUEUE_MAX_SIZE];
91     struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
92     struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
93 } VirtQueueElement;
94 
95 #define VIRTIO_PCI_QUEUE_MAX 64
96 
97 #define VIRTIO_NO_VECTOR 0xffff
98 
99 #define TYPE_VIRTIO_DEVICE "virtio-device"
100 #define VIRTIO_DEVICE_GET_CLASS(obj) \
101         OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
102 #define VIRTIO_DEVICE_CLASS(klass) \
103         OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
104 #define VIRTIO_DEVICE(obj) \
105         OBJECT_CHECK(VirtIODevice, (obj), TYPE_VIRTIO_DEVICE)
106 
107 enum virtio_device_endian {
108     VIRTIO_DEVICE_ENDIAN_UNKNOWN,
109     VIRTIO_DEVICE_ENDIAN_LITTLE,
110     VIRTIO_DEVICE_ENDIAN_BIG,
111 };
112 
113 struct VirtIODevice
114 {
115     DeviceState parent_obj;
116     const char *name;
117     uint8_t status;
118     uint8_t isr;
119     uint16_t queue_sel;
120     uint32_t guest_features;
121     size_t config_len;
122     void *config;
123     uint16_t config_vector;
124     int nvectors;
125     VirtQueue *vq;
126     uint16_t device_id;
127     bool vm_running;
128     VMChangeStateEntry *vmstate;
129     char *bus_name;
130     uint8_t device_endian;
131 };
132 
133 typedef struct VirtioDeviceClass {
134     /*< private >*/
135     DeviceClass parent;
136     /*< public >*/
137 
138     /* This is what a VirtioDevice must implement */
139     DeviceRealize realize;
140     DeviceUnrealize unrealize;
141     uint32_t (*get_features)(VirtIODevice *vdev, uint32_t requested_features);
142     uint32_t (*bad_features)(VirtIODevice *vdev);
143     void (*set_features)(VirtIODevice *vdev, uint32_t val);
144     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
145     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
146     void (*reset)(VirtIODevice *vdev);
147     void (*set_status)(VirtIODevice *vdev, uint8_t val);
148     /* Test and clear event pending status.
149      * Should be called after unmask to avoid losing events.
150      * If backend does not support masking,
151      * must check in frontend instead.
152      */
153     bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
154     /* Mask/unmask events from this vq. Any events reported
155      * while masked will become pending.
156      * If backend does not support masking,
157      * must mask in frontend instead.
158      */
159     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
160     void (*save)(VirtIODevice *vdev, QEMUFile *f);
161     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
162 } VirtioDeviceClass;
163 
164 void virtio_init(VirtIODevice *vdev, const char *name,
165                          uint16_t device_id, size_t config_size);
166 void virtio_cleanup(VirtIODevice *vdev);
167 
168 /* Set the child bus name. */
169 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
170 
171 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
172                             void (*handle_output)(VirtIODevice *,
173                                                   VirtQueue *));
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_fill(VirtQueue *vq, const VirtQueueElement *elem,
181                     unsigned int len, unsigned int idx);
182 
183 void virtqueue_map_sg(struct iovec *sg, hwaddr *addr,
184     size_t num_sg, int is_write);
185 int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
186 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
187                           unsigned int out_bytes);
188 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
189                                unsigned int *out_bytes,
190                                unsigned max_in_bytes, unsigned max_out_bytes);
191 
192 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
193 
194 void virtio_save(VirtIODevice *vdev, QEMUFile *f);
195 
196 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
197 
198 void virtio_notify_config(VirtIODevice *vdev);
199 
200 void virtio_queue_set_notification(VirtQueue *vq, int enable);
201 
202 int virtio_queue_ready(VirtQueue *vq);
203 
204 int virtio_queue_empty(VirtQueue *vq);
205 
206 /* Host binding interface.  */
207 
208 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
209 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
210 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
211 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
212 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
213 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
214 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
215 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
216 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
217 int virtio_queue_get_num(VirtIODevice *vdev, int n);
218 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
219 void virtio_queue_notify(VirtIODevice *vdev, int n);
220 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
221 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
222 void virtio_set_status(VirtIODevice *vdev, uint8_t val);
223 void virtio_reset(void *opaque);
224 void virtio_update_irq(VirtIODevice *vdev);
225 int virtio_set_features(VirtIODevice *vdev, uint32_t val);
226 
227 /* Base devices.  */
228 typedef struct VirtIOBlkConf VirtIOBlkConf;
229 struct virtio_net_conf;
230 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
231                               struct virtio_net_conf *net,
232                               uint32_t host_features);
233 typedef struct virtio_serial_conf virtio_serial_conf;
234 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
235 typedef struct VirtIORNGConf VirtIORNGConf;
236 
237 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
238 	DEFINE_PROP_BIT("indirect_desc", _state, _field, \
239 			VIRTIO_RING_F_INDIRECT_DESC, true), \
240 	DEFINE_PROP_BIT("event_idx", _state, _field, \
241 			VIRTIO_RING_F_EVENT_IDX, true)
242 
243 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
244 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
245 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
246 hwaddr virtio_queue_get_ring_addr(VirtIODevice *vdev, int n);
247 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
248 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
249 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
250 hwaddr virtio_queue_get_ring_size(VirtIODevice *vdev, int n);
251 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
252 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
253 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
254 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
255 uint16_t virtio_get_queue_index(VirtQueue *vq);
256 int virtio_queue_get_id(VirtQueue *vq);
257 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
258 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
259                                                 bool with_irqfd);
260 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
261 void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
262                                                bool set_handler);
263 void virtio_queue_notify_vq(VirtQueue *vq);
264 void virtio_irq(VirtQueue *vq);
265 
266 static inline bool virtio_is_big_endian(VirtIODevice *vdev)
267 {
268     assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
269     return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
270 }
271 #endif
272