linux/include/uapi/linux/virtio_pci.h
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   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: */
 118struct 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
 129struct 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: */
 135struct 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: */
 161struct 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
 200