summaryrefslogtreecommitdiffstats
path: root/drivers/virtio/virtio_pci.h
blob: cc753ed7b3d6c5c62e934590dcfc5028aff09dfa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/* SPDX-License-Identifier: BSD-3-Clause */
/*
 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
 *
 * From Linux kernel include/uapi/linux/virtio_pci.h
 */

#ifndef _LINUX_VIRTIO_PCI_H
#define _LINUX_VIRTIO_PCI_H

#ifndef VIRTIO_PCI_NO_LEGACY

/* A 32-bit r/o bitmask of the features supported by the host */
#define VIRTIO_PCI_HOST_FEATURES	0

/* A 32-bit r/w bitmask of features activated by the guest */
#define VIRTIO_PCI_GUEST_FEATURES	4

/* A 32-bit r/w PFN for the currently selected queue */
#define VIRTIO_PCI_QUEUE_PFN		8

/* A 16-bit r/o queue size for the currently selected queue */
#define VIRTIO_PCI_QUEUE_NUM		12

/* A 16-bit r/w queue selector */
#define VIRTIO_PCI_QUEUE_SEL		14

/* A 16-bit r/w queue notifier */
#define VIRTIO_PCI_QUEUE_NOTIFY		16

/* An 8-bit device status register */
#define VIRTIO_PCI_STATUS		18

/*
 * An 8-bit r/o interrupt status register. Reading the value will return the
 * current contents of the ISR and will also clear it. This is effectively
 * a read-and-acknowledge.
 */
#define VIRTIO_PCI_ISR			19

/* MSI-X registers: only enabled if MSI-X is enabled */

/* A 16-bit vector for configuration changes */
#define VIRTIO_MSI_CONFIG_VECTOR	20
/* A 16-bit vector for selected queue notifications */
#define VIRTIO_MSI_QUEUE_VECTOR		22

/*
 * The remaining space is defined by each driver as the per-driver
 * configuration space
 */
#define VIRTIO_PCI_CONFIG_OFF(msix)	((msix) ? 24 : 20)

/* Virtio ABI version, this must match exactly */
#define VIRTIO_PCI_ABI_VERSION		0

/*
 * How many bits to shift physical queue address written to QUEUE_PFN.
 * 12 is historical, and due to x86 page size.
 */
#define VIRTIO_PCI_QUEUE_ADDR_SHIFT	12

/*
 * The alignment to use between consumer and producer parts of vring.
 * x86 pagesize again.
 */
#define VIRTIO_PCI_VRING_ALIGN		4096

#endif /* VIRTIO_PCI_NO_LEGACY */

/* The bit of the ISR which indicates a device configuration change */
#define VIRTIO_PCI_ISR_CONFIG		0x2
/* Vector value used to disable MSI for queue */
#define VIRTIO_MSI_NO_VECTOR		0xffff

#ifndef VIRTIO_PCI_NO_MODERN

/* IDs for different capabilities.  Must all exist. */

/* Common configuration */
#define VIRTIO_PCI_CAP_COMMON_CFG	1
/* Notifications */
#define VIRTIO_PCI_CAP_NOTIFY_CFG	2
/* ISR access */
#define VIRTIO_PCI_CAP_ISR_CFG		3
/* Device specific configuration */
#define VIRTIO_PCI_CAP_DEVICE_CFG	4
/* PCI configuration access */
#define VIRTIO_PCI_CAP_PCI_CFG		5

/* This is the PCI capability header: */
struct virtio_pci_cap {
	__u8 cap_vndr;		/* Generic PCI field: PCI_CAP_ID_VNDR */
	__u8 cap_next;		/* Generic PCI field: next ptr */
	__u8 cap_len;		/* Generic PCI field: capability length */
	__u8 cfg_type;		/* Identifies the structure */
	__u8 bar;		/* Where to find it */
	__u8 padding[3];	/* Pad to full dword */
	__le32 offset;		/* Offset within bar */
	__le32 length;		/* Length of the structure, in bytes */
};

struct virtio_pci_notify_cap {
	struct virtio_pci_cap cap;
	__le32 notify_off_multiplier;	/* Multiplier for queue_notify_off */
};

/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
struct virtio_pci_common_cfg {
	/* About the whole device */
	__le32 device_feature_select;	/* read-write */
	__le32 device_feature;		/* read-only */
	__le32 guest_feature_select;	/* read-write */
	__le32 guest_feature;		/* read-write */
	__le16 msix_config;		/* read-write */
	__le16 num_queues;		/* read-only */
	__u8 device_status;		/* read-write */
	__u8 config_generation;		/* read-only */

	/* About a specific virtqueue */
	__le16 queue_select;		/* read-write */
	__le16 queue_size;		/* read-write, power of 2 */
	__le16 queue_msix_vector;	/* read-write */
	__le16 queue_enable;		/* read-write */
	__le16 queue_notify_off;	/* read-only */
	__le32 queue_desc_lo;		/* read-write */
	__le32 queue_desc_hi;		/* read-write */
	__le32 queue_avail_lo;		/* read-write */
	__le32 queue_avail_hi;		/* read-write */
	__le32 queue_used_lo;		/* read-write */
	__le32 queue_used_hi;		/* read-write */
};

/* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
struct virtio_pci_cfg_cap {
	struct virtio_pci_cap cap;
	__u8 pci_cfg_data[4];		/* Data for BAR access */
};

/* Macro versions of offsets for the Old Timers! */
#define VIRTIO_PCI_CAP_VNDR		0
#define VIRTIO_PCI_CAP_NEXT		1
#define VIRTIO_PCI_CAP_LEN		2
#define VIRTIO_PCI_CAP_CFG_TYPE		3
#define VIRTIO_PCI_CAP_BAR		4
#define VIRTIO_PCI_CAP_OFFSET		8
#define VIRTIO_PCI_CAP_LENGTH		12

#define VIRTIO_PCI_NOTIFY_CAP_MULT	16

#define VIRTIO_PCI_COMMON_DFSELECT	0
#define VIRTIO_PCI_COMMON_DF		4
#define VIRTIO_PCI_COMMON_GFSELECT	8
#define VIRTIO_PCI_COMMON_GF		12
#define VIRTIO_PCI_COMMON_MSIX		16
#define VIRTIO_PCI_COMMON_NUMQ		18
#define VIRTIO_PCI_COMMON_STATUS	20
#define VIRTIO_PCI_COMMON_CFGGENERATION	21
#define VIRTIO_PCI_COMMON_Q_SELECT	22
#define VIRTIO_PCI_COMMON_Q_SIZE	24
#define VIRTIO_PCI_COMMON_Q_MSIX	26
#define VIRTIO_PCI_COMMON_Q_ENABLE	28
#define VIRTIO_PCI_COMMON_Q_NOFF	30
#define VIRTIO_PCI_COMMON_Q_DESCLO	32
#define VIRTIO_PCI_COMMON_Q_DESCHI	36
#define VIRTIO_PCI_COMMON_Q_AVAILLO	40
#define VIRTIO_PCI_COMMON_Q_AVAILHI	44
#define VIRTIO_PCI_COMMON_Q_USEDLO	48
#define VIRTIO_PCI_COMMON_Q_USEDHI	52

#endif /* VIRTIO_PCI_NO_MODERN */

#endif /* _LINUX_VIRTIO_PCI_H */