uapi/linux/virtio_pci.h

0001 /*
0002  * Virtio PCI driver
0003  *
0004  * This module allows virtio devices to be used over a virtual PCI device.
0005  * This can be used with QEMU based VMMs like KVM or Xen.
0006  *
0007  * Copyright IBM Corp. 2007
0008  *
0009  * Authors:
0010  *  Anthony Liguori  <aliguori@us.ibm.com>
0011  *
0012  * This header is BSD licensed so anyone can use the definitions to implement
0013  * compatible drivers/servers.
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  * 3. Neither the name of IBM nor the names of its contributors
0024  *    may be used to endorse or promote products derived from this software
0025  *    without specific prior written permission.
0026  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
0027  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0028  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0029  * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
0030  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
0031  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
0032  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
0033  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
0034  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
0035  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
0036  * SUCH DAMAGE.
0037  */
0038
0039 #ifndef _LINUX_VIRTIO_PCI_H
0040 #define _LINUX_VIRTIO_PCI_H
0041
0042 #include <linux/types.h>
0043
0044 #ifndef VIRTIO_PCI_NO_LEGACY
0045
0046 /* A 32-bit r/o bitmask of the features supported by the host */
0047 #define VIRTIO_PCI_HOST_FEATURES    0
0048
0049 /* A 32-bit r/w bitmask of features activated by the guest */
0050 #define VIRTIO_PCI_GUEST_FEATURES   4
0051
0052 /* A 32-bit r/w PFN for the currently selected queue */
0053 #define VIRTIO_PCI_QUEUE_PFN        8
0054
0055 /* A 16-bit r/o queue size for the currently selected queue */
0056 #define VIRTIO_PCI_QUEUE_NUM        12
0057
0058 /* A 16-bit r/w queue selector */
0059 #define VIRTIO_PCI_QUEUE_SEL        14
0060
0061 /* A 16-bit r/w queue notifier */
0062 #define VIRTIO_PCI_QUEUE_NOTIFY     16
0063
0064 /* An 8-bit device status register.  */
0065 #define VIRTIO_PCI_STATUS       18
0066
0067 /* An 8-bit r/o interrupt status register.  Reading the value will return the
0068  * current contents of the ISR and will also clear it.  This is effectively
0069  * a read-and-acknowledge. */
0070 #define VIRTIO_PCI_ISR          19
0071
0072 /* MSI-X registers: only enabled if MSI-X is enabled. */
0073 /* A 16-bit vector for configuration changes. */
0074 #define VIRTIO_MSI_CONFIG_VECTOR        20
0075 /* A 16-bit vector for selected queue notifications. */
0076 #define VIRTIO_MSI_QUEUE_VECTOR         22
0077
0078 /* The remaining space is defined by each driver as the per-driver
0079  * configuration space */
0080 #define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
0081 /* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
0082 #define VIRTIO_PCI_CONFIG(dev)  VIRTIO_PCI_CONFIG_OFF((dev)->msix_enabled)
0083
0084 /* Virtio ABI version, this must match exactly */
0085 #define VIRTIO_PCI_ABI_VERSION      0
0086
0087 /* How many bits to shift physical queue address written to QUEUE_PFN.
0088  * 12 is historical, and due to x86 page size. */
0089 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
0090
0091 /* The alignment to use between consumer and producer parts of vring.
0092  * x86 pagesize again. */
0093 #define VIRTIO_PCI_VRING_ALIGN      4096
0094
0095 #endif /* VIRTIO_PCI_NO_LEGACY */
0096
0097 /* The bit of the ISR which indicates a device configuration change. */
0098 #define VIRTIO_PCI_ISR_CONFIG       0x2
0099 /* Vector value used to disable MSI for queue */
0100 #define VIRTIO_MSI_NO_VECTOR            0xffff
0101
0102 #ifndef VIRTIO_PCI_NO_MODERN
0103
0104 /* IDs for different capabilities.  Must all exist. */
0105
0106 /* Common configuration */
0107 #define VIRTIO_PCI_CAP_COMMON_CFG   1
0108 /* Notifications */
0109 #define VIRTIO_PCI_CAP_NOTIFY_CFG   2
0110 /* ISR access */
0111 #define VIRTIO_PCI_CAP_ISR_CFG      3
0112 /* Device specific configuration */
0113 #define VIRTIO_PCI_CAP_DEVICE_CFG   4
0114 /* PCI configuration access */
0115 #define VIRTIO_PCI_CAP_PCI_CFG      5
0116 /* Additional shared memory capability */
0117 #define VIRTIO_PCI_CAP_SHARED_MEMORY_CFG 8
0118
0119 /* This is the PCI capability header: */
0120 struct virtio_pci_cap {
0121     __u8 cap_vndr;      /* Generic PCI field: PCI_CAP_ID_VNDR */
0122     __u8 cap_next;      /* Generic PCI field: next ptr. */
0123     __u8 cap_len;       /* Generic PCI field: capability length */
0124     __u8 cfg_type;      /* Identifies the structure. */
0125     __u8 bar;       /* Where to find it. */
0126     __u8 id;        /* Multiple capabilities of the same type */
0127     __u8 padding[2];    /* Pad to full dword. */
0128     __le32 offset;      /* Offset within bar. */
0129     __le32 length;      /* Length of the structure, in bytes. */
0130 };
0131
0132 struct virtio_pci_cap64 {
0133     struct virtio_pci_cap cap;
0134     __le32 offset_hi;             /* Most sig 32 bits of offset */
0135     __le32 length_hi;             /* Most sig 32 bits of length */
0136 };
0137
0138 struct virtio_pci_notify_cap {
0139     struct virtio_pci_cap cap;
0140     __le32 notify_off_multiplier;   /* Multiplier for queue_notify_off. */
0141 };
0142
0143 /* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
0144 struct virtio_pci_common_cfg {
0145     /* About the whole device. */
0146     __le32 device_feature_select;   /* read-write */
0147     __le32 device_feature;      /* read-only */
0148     __le32 guest_feature_select;    /* read-write */
0149     __le32 guest_feature;       /* read-write */
0150     __le16 msix_config;     /* read-write */
0151     __le16 num_queues;      /* read-only */
0152     __u8 device_status;     /* read-write */
0153     __u8 config_generation;     /* read-only */
0154
0155     /* About a specific virtqueue. */
0156     __le16 queue_select;        /* read-write */
0157     __le16 queue_size;      /* read-write, power of 2. */
0158     __le16 queue_msix_vector;   /* read-write */
0159     __le16 queue_enable;        /* read-write */
0160     __le16 queue_notify_off;    /* read-only */
0161     __le32 queue_desc_lo;       /* read-write */
0162     __le32 queue_desc_hi;       /* read-write */
0163     __le32 queue_avail_lo;      /* read-write */
0164     __le32 queue_avail_hi;      /* read-write */
0165     __le32 queue_used_lo;       /* read-write */
0166     __le32 queue_used_hi;       /* read-write */
0167 };
0168
0169 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
0170 struct virtio_pci_cfg_cap {
0171     struct virtio_pci_cap cap;
0172     __u8 pci_cfg_data[4]; /* Data for BAR access. */
0173 };
0174
0175 /* Macro versions of offsets for the Old Timers! */
0176 #define VIRTIO_PCI_CAP_VNDR     0
0177 #define VIRTIO_PCI_CAP_NEXT     1
0178 #define VIRTIO_PCI_CAP_LEN      2
0179 #define VIRTIO_PCI_CAP_CFG_TYPE     3
0180 #define VIRTIO_PCI_CAP_BAR      4
0181 #define VIRTIO_PCI_CAP_OFFSET       8
0182 #define VIRTIO_PCI_CAP_LENGTH       12
0183
0184 #define VIRTIO_PCI_NOTIFY_CAP_MULT  16
0185
0186 #define VIRTIO_PCI_COMMON_DFSELECT  0
0187 #define VIRTIO_PCI_COMMON_DF        4
0188 #define VIRTIO_PCI_COMMON_GFSELECT  8
0189 #define VIRTIO_PCI_COMMON_GF        12
0190 #define VIRTIO_PCI_COMMON_MSIX      16
0191 #define VIRTIO_PCI_COMMON_NUMQ      18
0192 #define VIRTIO_PCI_COMMON_STATUS    20
0193 #define VIRTIO_PCI_COMMON_CFGGENERATION 21
0194 #define VIRTIO_PCI_COMMON_Q_SELECT  22
0195 #define VIRTIO_PCI_COMMON_Q_SIZE    24
0196 #define VIRTIO_PCI_COMMON_Q_MSIX    26
0197 #define VIRTIO_PCI_COMMON_Q_ENABLE  28
0198 #define VIRTIO_PCI_COMMON_Q_NOFF    30
0199 #define VIRTIO_PCI_COMMON_Q_DESCLO  32
0200 #define VIRTIO_PCI_COMMON_Q_DESCHI  36
0201 #define VIRTIO_PCI_COMMON_Q_AVAILLO 40
0202 #define VIRTIO_PCI_COMMON_Q_AVAILHI 44
0203 #define VIRTIO_PCI_COMMON_Q_USEDLO  48
0204 #define VIRTIO_PCI_COMMON_Q_USEDHI  52
0205 #define VIRTIO_PCI_COMMON_Q_NDATA   56
0206 #define VIRTIO_PCI_COMMON_Q_RESET   58
0207
0208 #endif /* VIRTIO_PCI_NO_MODERN */
0209
0210 #endif