1 /*
2 * Virtio PCI driver
3 *
4 * This module allows virtio devices to be used over a virtual PCI device.
5 * This can be used with QEMU based VMMs like KVM or Xen.
6 *
7 * Copyright IBM Corp. 2007
8 *
9 * Authors:
10 * Anthony Liguori <aliguori@us.ibm.com>
11 *
12 * This header is BSD licensed so anyone can use the definitions to implement
13 * compatible drivers/servers.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of IBM nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39 #ifndef _LINUX_VIRTIO_PCI_H
40 #define _LINUX_VIRTIO_PCI_H
41
42 #include <linux/types.h>
43
44 #ifndef VIRTIO_PCI_NO_LEGACY
45
46 /* A 32-bit r/o bitmask of the features supported by the host */
47 #define VIRTIO_PCI_HOST_FEATURES 0
48
49 /* A 32-bit r/w bitmask of features activated by the guest */
50 #define VIRTIO_PCI_GUEST_FEATURES 4
51
52 /* A 32-bit r/w PFN for the currently selected queue */
53 #define VIRTIO_PCI_QUEUE_PFN 8
54
55 /* A 16-bit r/o queue size for the currently selected queue */
56 #define VIRTIO_PCI_QUEUE_NUM 12
57
58 /* A 16-bit r/w queue selector */
59 #define VIRTIO_PCI_QUEUE_SEL 14
60
61 /* A 16-bit r/w queue notifier */
62 #define VIRTIO_PCI_QUEUE_NOTIFY 16
63
64 /* An 8-bit device status register. */
65 #define VIRTIO_PCI_STATUS 18
66
67 /* An 8-bit r/o interrupt status register. Reading the value will return the
68 * current contents of the ISR and will also clear it. This is effectively
69 * a read-and-acknowledge. */
70 #define VIRTIO_PCI_ISR 19
71
72 /* MSI-X registers: only enabled if MSI-X is enabled. */
73 /* A 16-bit vector for configuration changes. */
74 #define VIRTIO_MSI_CONFIG_VECTOR 20
75 /* A 16-bit vector for selected queue notifications. */
76 #define VIRTIO_MSI_QUEUE_VECTOR 22
77
78 /* The remaining space is defined by each driver as the per-driver
79 * configuration space */
80 #define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
81 /* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
82 #define VIRTIO_PCI_CONFIG(dev) VIRTIO_PCI_CONFIG_OFF((dev)->msix_enabled)
83
84 /* Virtio ABI version, this must match exactly */
85 #define VIRTIO_PCI_ABI_VERSION 0
86
87 /* How many bits to shift physical queue address written to QUEUE_PFN.
88 * 12 is historical, and due to x86 page size. */
89 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
90
91 /* The alignment to use between consumer and producer parts of vring.
92 * x86 pagesize again. */
93 #define VIRTIO_PCI_VRING_ALIGN 4096
94
95 #endif /* VIRTIO_PCI_NO_LEGACY */
96
97 /* The bit of the ISR which indicates a device configuration change. */
98 #define VIRTIO_PCI_ISR_CONFIG 0x2
99 /* Vector value used to disable MSI for queue */
100 #define VIRTIO_MSI_NO_VECTOR 0xffff
101
102 #ifndef VIRTIO_PCI_NO_MODERN
103
104 /* IDs for different capabilities. Must all exist. */
105
106 /* Common configuration */
107 #define VIRTIO_PCI_CAP_COMMON_CFG 1
108 /* Notifications */
109 #define VIRTIO_PCI_CAP_NOTIFY_CFG 2
110 /* ISR access */
111 #define VIRTIO_PCI_CAP_ISR_CFG 3
112 /* Device specific configuration */
113 #define VIRTIO_PCI_CAP_DEVICE_CFG 4
114 /* PCI configuration access */
115 #define VIRTIO_PCI_CAP_PCI_CFG 5
116
117 /* This is the PCI capability header: */
118 struct virtio_pci_cap {
119 __u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */
120 __u8 cap_next; /* Generic PCI field: next ptr. */
121 __u8 cap_len; /* Generic PCI field: capability length */
122 __u8 cfg_type; /* Identifies the structure. */
123 __u8 bar; /* Where to find it. */
124 __u8 padding[3]; /* Pad to full dword. */
125 __le32 offset; /* Offset within bar. */
126 __le32 length; /* Length of the structure, in bytes. */
127 };
128
129 struct virtio_pci_notify_cap {
130 struct virtio_pci_cap cap;
131 __le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
132 };
133
134 /* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
135 struct virtio_pci_common_cfg {
136 /* About the whole device. */
137 __le32 device_feature_select; /* read-write */
138 __le32 device_feature; /* read-only */
139 __le32 guest_feature_select; /* read-write */
140 __le32 guest_feature; /* read-write */
141 __le16 msix_config; /* read-write */
142 __le16 num_queues; /* read-only */
143 __u8 device_status; /* read-write */
144 __u8 config_generation; /* read-only */
145
146 /* About a specific virtqueue. */
147 __le16 queue_select; /* read-write */
148 __le16 queue_size; /* read-write, power of 2. */
149 __le16 queue_msix_vector; /* read-write */
150 __le16 queue_enable; /* read-write */
151 __le16 queue_notify_off; /* read-only */
152 __le32 queue_desc_lo; /* read-write */
153 __le32 queue_desc_hi; /* read-write */
154 __le32 queue_avail_lo; /* read-write */
155 __le32 queue_avail_hi; /* read-write */
156 __le32 queue_used_lo; /* read-write */
157 __le32 queue_used_hi; /* read-write */
158 };
159
160 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
161 struct virtio_pci_cfg_cap {
162 struct virtio_pci_cap cap;
163 __u8 pci_cfg_data[4]; /* Data for BAR access. */
164 };
165
166 /* Macro versions of offsets for the Old Timers! */
167 #define VIRTIO_PCI_CAP_VNDR 0
168 #define VIRTIO_PCI_CAP_NEXT 1
169 #define VIRTIO_PCI_CAP_LEN 2
170 #define VIRTIO_PCI_CAP_CFG_TYPE 3
171 #define VIRTIO_PCI_CAP_BAR 4
172 #define VIRTIO_PCI_CAP_OFFSET 8
173 #define VIRTIO_PCI_CAP_LENGTH 12
174
175 #define VIRTIO_PCI_NOTIFY_CAP_MULT 16
176
177 #define VIRTIO_PCI_COMMON_DFSELECT 0
178 #define VIRTIO_PCI_COMMON_DF 4
179 #define VIRTIO_PCI_COMMON_GFSELECT 8
180 #define VIRTIO_PCI_COMMON_GF 12
181 #define VIRTIO_PCI_COMMON_MSIX 16
182 #define VIRTIO_PCI_COMMON_NUMQ 18
183 #define VIRTIO_PCI_COMMON_STATUS 20
184 #define VIRTIO_PCI_COMMON_CFGGENERATION 21
185 #define VIRTIO_PCI_COMMON_Q_SELECT 22
186 #define VIRTIO_PCI_COMMON_Q_SIZE 24
187 #define VIRTIO_PCI_COMMON_Q_MSIX 26
188 #define VIRTIO_PCI_COMMON_Q_ENABLE 28
189 #define VIRTIO_PCI_COMMON_Q_NOFF 30
190 #define VIRTIO_PCI_COMMON_Q_DESCLO 32
191 #define VIRTIO_PCI_COMMON_Q_DESCHI 36
192 #define VIRTIO_PCI_COMMON_Q_AVAILLO 40
193 #define VIRTIO_PCI_COMMON_Q_AVAILHI 44
194 #define VIRTIO_PCI_COMMON_Q_USEDLO 48
195 #define VIRTIO_PCI_COMMON_Q_USEDHI 52
196
197 #endif /* VIRTIO_PCI_NO_MODERN */
198
199 #endif