1 #ifndef _VIRTIO_RING_H
2 #define _VIRTIO_RING_H
3
4 #include "types.h" // u64
5 #include "memmap.h" // PAGE_SIZE
6
7 /* Status byte for guest to report progress, and synchronize features. */
8 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
9 #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
10 /* We have found a driver for the device. */
11 #define VIRTIO_CONFIG_S_DRIVER 2
12 /* Driver has used its parts of the config, and is happy */
13 #define VIRTIO_CONFIG_S_DRIVER_OK 4
14 /* Driver has finished configuring features */
15 #define VIRTIO_CONFIG_S_FEATURES_OK 8
16 /* We've given up on this device. */
17 #define VIRTIO_CONFIG_S_FAILED 0x80
18
19 /* v1.0 compliant. */
20 #define VIRTIO_F_VERSION_1 32
21 #define VIRTIO_F_IOMMU_PLATFORM 33
22
23 #define MAX_QUEUE_NUM (256)
24
25 #define VRING_DESC_F_NEXT 1
26 #define VRING_DESC_F_WRITE 2
27
28 #define VRING_AVAIL_F_NO_INTERRUPT 1
29
30 #define VRING_USED_F_NO_NOTIFY 1
31
32 struct vring_desc
33 {
34 u64 addr;
35 u32 len;
36 u16 flags;
37 u16 next;
38 };
39
40 struct vring_avail
41 {
42 u16 flags;
43 u16 idx;
44 u16 ring[0];
45 };
46
47 struct vring_used_elem
48 {
49 u32 id;
50 u32 len;
51 };
52
53 struct vring_used
54 {
55 u16 flags;
56 u16 idx;
57 struct vring_used_elem ring[];
58 };
59
60 struct vring {
61 unsigned int num;
62 struct vring_desc *desc;
63 struct vring_avail *avail;
64 struct vring_used *used;
65 };
66
67 #define vring_size(num) \
68 (ALIGN(sizeof(struct vring_desc) * num + sizeof(struct vring_avail) \
69 + sizeof(u16) * num, PAGE_SIZE) \
70 + sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num)
71
72 typedef unsigned char virtio_queue_t[vring_size(MAX_QUEUE_NUM)];
73
74 struct vring_virtqueue {
75 virtio_queue_t queue;
76 struct vring vring;
77 u16 free_head;
78 u16 last_used_idx;
79 u16 vdata[MAX_QUEUE_NUM];
80 /* PCI */
81 int queue_index;
82 int queue_notify_off;
83 };
84
85 struct vring_list {
86 char *addr;
87 unsigned int length;
88 };
89
90 static inline void
vring_init(struct vring * vr,unsigned int num,unsigned char * queue)91 vring_init(struct vring *vr, unsigned int num, unsigned char *queue)
92 {
93 ASSERT32FLAT();
94 vr->num = num;
95
96 /* physical address of desc must be page aligned */
97 vr->desc = (void*)ALIGN((u32)queue, PAGE_SIZE);
98
99 vr->avail = (struct vring_avail *)&vr->desc[num];
100 /* disable interrupts */
101 vr->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
102
103 /* physical address of used must be page aligned */
104 vr->used = (void*)ALIGN((u32)&vr->avail->ring[num], PAGE_SIZE);
105
106 int i;
107 for (i = 0; i < num - 1; i++)
108 vr->desc[i].next = i + 1;
109 vr->desc[i].next = 0;
110 }
111
112 struct vp_device;
113 int vring_more_used(struct vring_virtqueue *vq);
114 void vring_detach(struct vring_virtqueue *vq, unsigned int head);
115 int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len);
116 void vring_add_buf(struct vring_virtqueue *vq, struct vring_list list[],
117 unsigned int out, unsigned int in,
118 int index, int num_added);
119 void vring_kick(struct vp_device *vp, struct vring_virtqueue *vq, int num_added);
120
121 #endif /* _VIRTIO_RING_H_ */
122