include/standard-headers/linux/virtio_pci.h

   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 "standard-headers/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         uint8_t cap_vndr;               /* Generic PCI field: PCI_CAP_ID_VNDR */
 120         uint8_t cap_next;               /* Generic PCI field: next ptr. */
 121         uint8_t cap_len;                /* Generic PCI field: capability length */
 122         uint8_t cfg_type;               /* Identifies the structure. */
 123         uint8_t bar;            /* Where to find it. */
 124         uint8_t padding[3];     /* Pad to full dword. */
 125         uint32_t offset;                /* Offset within bar. */
 126         uint32_t length;                /* Length of the structure, in bytes. */
 127 };
 128
 129 struct virtio_pci_notify_cap {
 130         struct virtio_pci_cap cap;
 131         uint32_t 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         uint32_t device_feature_select; /* read-write */
 138         uint32_t device_feature;                /* read-only */
 139         uint32_t guest_feature_select;  /* read-write */
 140         uint32_t guest_feature;         /* read-write */
 141         uint16_t msix_config;           /* read-write */
 142         uint16_t num_queues;            /* read-only */
 143         uint8_t device_status;          /* read-write */
 144         uint8_t config_generation;              /* read-only */
 145
 146         /* About a specific virtqueue. */
 147         uint16_t queue_select;          /* read-write */
 148         uint16_t queue_size;            /* read-write, power of 2. */
 149         uint16_t queue_msix_vector;     /* read-write */
 150         uint16_t queue_enable;          /* read-write */
 151         uint16_t queue_notify_off;      /* read-only */
 152         uint32_t queue_desc_lo;         /* read-write */
 153         uint32_t queue_desc_hi;         /* read-write */
 154         uint32_t queue_avail_lo;                /* read-write */
 155         uint32_t queue_avail_hi;                /* read-write */
 156         uint32_t queue_used_lo;         /* read-write */
 157         uint32_t 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         uint8_t 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