1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
4 *
5 * From Linux kernel include/uapi/linux/virtio_pci.h
6 */
7
8#ifndef _LINUX_VIRTIO_PCI_H
9#define _LINUX_VIRTIO_PCI_H
10
11#ifndef VIRTIO_PCI_NO_LEGACY
12
13/* A 32-bit r/o bitmask of the features supported by the host */
14#define VIRTIO_PCI_HOST_FEATURES	0
15
16/* A 32-bit r/w bitmask of features activated by the guest */
17#define VIRTIO_PCI_GUEST_FEATURES	4
18
19/* A 32-bit r/w PFN for the currently selected queue */
20#define VIRTIO_PCI_QUEUE_PFN		8
21
22/* A 16-bit r/o queue size for the currently selected queue */
23#define VIRTIO_PCI_QUEUE_NUM		12
24
25/* A 16-bit r/w queue selector */
26#define VIRTIO_PCI_QUEUE_SEL		14
27
28/* A 16-bit r/w queue notifier */
29#define VIRTIO_PCI_QUEUE_NOTIFY		16
30
31/* An 8-bit device status register */
32#define VIRTIO_PCI_STATUS		18
33
34/*
35 * An 8-bit r/o interrupt status register. Reading the value will return the
36 * current contents of the ISR and will also clear it. This is effectively
37 * a read-and-acknowledge.
38 */
39#define VIRTIO_PCI_ISR			19
40
41/* MSI-X registers: only enabled if MSI-X is enabled */
42
43/* A 16-bit vector for configuration changes */
44#define VIRTIO_MSI_CONFIG_VECTOR	20
45/* A 16-bit vector for selected queue notifications */
46#define VIRTIO_MSI_QUEUE_VECTOR		22
47
48/*
49 * The remaining space is defined by each driver as the per-driver
50 * configuration space
51 */
52#define VIRTIO_PCI_CONFIG_OFF(msix)	((msix) ? 24 : 20)
53
54/* Virtio ABI version, this must match exactly */
55#define VIRTIO_PCI_ABI_VERSION		0
56
57/*
58 * How many bits to shift physical queue address written to QUEUE_PFN.
59 * 12 is historical, and due to x86 page size.
60 */
61#define VIRTIO_PCI_QUEUE_ADDR_SHIFT	12
62
63/*
64 * The alignment to use between consumer and producer parts of vring.
65 * x86 pagesize again.
66 */
67#define VIRTIO_PCI_VRING_ALIGN		4096
68
69#endif /* VIRTIO_PCI_NO_LEGACY */
70
71/* The bit of the ISR which indicates a device configuration change */
72#define VIRTIO_PCI_ISR_CONFIG		0x2
73/* Vector value used to disable MSI for queue */
74#define VIRTIO_MSI_NO_VECTOR		0xffff
75
76#ifndef VIRTIO_PCI_NO_MODERN
77
78/* IDs for different capabilities.  Must all exist. */
79
80/* Common configuration */
81#define VIRTIO_PCI_CAP_COMMON_CFG	1
82/* Notifications */
83#define VIRTIO_PCI_CAP_NOTIFY_CFG	2
84/* ISR access */
85#define VIRTIO_PCI_CAP_ISR_CFG		3
86/* Device specific configuration */
87#define VIRTIO_PCI_CAP_DEVICE_CFG	4
88/* PCI configuration access */
89#define VIRTIO_PCI_CAP_PCI_CFG		5
90
91/* This is the PCI capability header: */
92struct virtio_pci_cap {
93	__u8 cap_vndr;		/* Generic PCI field: PCI_CAP_ID_VNDR */
94	__u8 cap_next;		/* Generic PCI field: next ptr */
95	__u8 cap_len;		/* Generic PCI field: capability length */
96	__u8 cfg_type;		/* Identifies the structure */
97	__u8 bar;		/* Where to find it */
98	__u8 padding[3];	/* Pad to full dword */
99	__le32 offset;		/* Offset within bar */
100	__le32 length;		/* Length of the structure, in bytes */
101};
102
103struct virtio_pci_notify_cap {
104	struct virtio_pci_cap cap;
105	__le32 notify_off_multiplier;	/* Multiplier for queue_notify_off */
106};
107
108/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
109struct virtio_pci_common_cfg {
110	/* About the whole device */
111	__le32 device_feature_select;	/* read-write */
112	__le32 device_feature;		/* read-only */
113	__le32 guest_feature_select;	/* read-write */
114	__le32 guest_feature;		/* read-write */
115	__le16 msix_config;		/* read-write */
116	__le16 num_queues;		/* read-only */
117	__u8 device_status;		/* read-write */
118	__u8 config_generation;		/* read-only */
119
120	/* About a specific virtqueue */
121	__le16 queue_select;		/* read-write */
122	__le16 queue_size;		/* read-write, power of 2 */
123	__le16 queue_msix_vector;	/* read-write */
124	__le16 queue_enable;		/* read-write */
125	__le16 queue_notify_off;	/* read-only */
126	__le32 queue_desc_lo;		/* read-write */
127	__le32 queue_desc_hi;		/* read-write */
128	__le32 queue_avail_lo;		/* read-write */
129	__le32 queue_avail_hi;		/* read-write */
130	__le32 queue_used_lo;		/* read-write */
131	__le32 queue_used_hi;		/* read-write */
132};
133
134/* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
135struct virtio_pci_cfg_cap {
136	struct virtio_pci_cap cap;
137	__u8 pci_cfg_data[4];		/* Data for BAR access */
138};
139
140/* Macro versions of offsets for the Old Timers! */
141#define VIRTIO_PCI_CAP_VNDR		0
142#define VIRTIO_PCI_CAP_NEXT		1
143#define VIRTIO_PCI_CAP_LEN		2
144#define VIRTIO_PCI_CAP_CFG_TYPE		3
145#define VIRTIO_PCI_CAP_BAR		4
146#define VIRTIO_PCI_CAP_OFFSET		8
147#define VIRTIO_PCI_CAP_LENGTH		12
148
149#define VIRTIO_PCI_NOTIFY_CAP_MULT	16
150
151#define VIRTIO_PCI_COMMON_DFSELECT	0
152#define VIRTIO_PCI_COMMON_DF		4
153#define VIRTIO_PCI_COMMON_GFSELECT	8
154#define VIRTIO_PCI_COMMON_GF		12
155#define VIRTIO_PCI_COMMON_MSIX		16
156#define VIRTIO_PCI_COMMON_NUMQ		18
157#define VIRTIO_PCI_COMMON_STATUS	20
158#define VIRTIO_PCI_COMMON_CFGGENERATION	21
159#define VIRTIO_PCI_COMMON_Q_SELECT	22
160#define VIRTIO_PCI_COMMON_Q_SIZE	24
161#define VIRTIO_PCI_COMMON_Q_MSIX	26
162#define VIRTIO_PCI_COMMON_Q_ENABLE	28
163#define VIRTIO_PCI_COMMON_Q_NOFF	30
164#define VIRTIO_PCI_COMMON_Q_DESCLO	32
165#define VIRTIO_PCI_COMMON_Q_DESCHI	36
166#define VIRTIO_PCI_COMMON_Q_AVAILLO	40
167#define VIRTIO_PCI_COMMON_Q_AVAILHI	44
168#define VIRTIO_PCI_COMMON_Q_USEDLO	48
169#define VIRTIO_PCI_COMMON_Q_USEDHI	52
170
171#endif /* VIRTIO_PCI_NO_MODERN */
172
173#endif /* _LINUX_VIRTIO_PCI_H */
174