| Current File : //usr/include/linux/virtio_pci.h |
/*
* Virtio PCI driver
*
* This module allows virtio devices to be used over a virtual PCI device.
* This can be used with QEMU based VMMs like KVM or Xen.
*
* Copyright IBM Corp. 2007
*
* Authors:
* Anthony Liguori <[email protected]>
*
* This header is BSD licensed so anyone can use the definitions to implement
* compatible drivers/servers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of IBM nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _LINUX_VIRTIO_PCI_H
#define _LINUX_VIRTIO_PCI_H
#include <linux/types.h>
#ifndef VIRTIO_PCI_NO_LEGACY
/* A 32-bit r/o bitmask of the features supported by the host */
#define VIRTIO_PCI_HOST_FEATURES 0
/* A 32-bit r/w bitmask of features activated by the guest */
#define VIRTIO_PCI_GUEST_FEATURES 4
/* A 32-bit r/w PFN for the currently selected queue */
#define VIRTIO_PCI_QUEUE_PFN 8
/* A 16-bit r/o queue size for the currently selected queue */
#define VIRTIO_PCI_QUEUE_NUM 12
/* A 16-bit r/w queue selector */
#define VIRTIO_PCI_QUEUE_SEL 14
/* A 16-bit r/w queue notifier */
#define VIRTIO_PCI_QUEUE_NOTIFY 16
/* An 8-bit device status register. */
#define VIRTIO_PCI_STATUS 18
/* An 8-bit r/o interrupt status register. Reading the value will return the
* current contents of the ISR and will also clear it. This is effectively
* a read-and-acknowledge. */
#define VIRTIO_PCI_ISR 19
/* MSI-X registers: only enabled if MSI-X is enabled. */
/* A 16-bit vector for configuration changes. */
#define VIRTIO_MSI_CONFIG_VECTOR 20
/* A 16-bit vector for selected queue notifications. */
#define VIRTIO_MSI_QUEUE_VECTOR 22
/* The remaining space is defined by each driver as the per-driver
* configuration space */
#define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20)
/* Virtio ABI version, this must match exactly */
#define VIRTIO_PCI_ABI_VERSION 0
/* How many bits to shift physical queue address written to QUEUE_PFN.
* 12 is historical, and due to x86 page size. */
#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
/* The alignment to use between consumer and producer parts of vring.
* x86 pagesize again. */
#define VIRTIO_PCI_VRING_ALIGN 4096
#endif /* VIRTIO_PCI_NO_LEGACY */
/* The bit of the ISR which indicates a device configuration change. */
#define VIRTIO_PCI_ISR_CONFIG 0x2
/* Vector value used to disable MSI for queue */
#define VIRTIO_MSI_NO_VECTOR 0xffff
#ifndef VIRTIO_PCI_NO_MODERN
/* IDs for different capabilities. Must all exist. */
/* Common configuration */
#define VIRTIO_PCI_CAP_COMMON_CFG 1
/* Notifications */
#define VIRTIO_PCI_CAP_NOTIFY_CFG 2
/* ISR access */
#define VIRTIO_PCI_CAP_ISR_CFG 3
/* Device specific configuration */
#define VIRTIO_PCI_CAP_DEVICE_CFG 4
/* PCI configuration access */
#define VIRTIO_PCI_CAP_PCI_CFG 5
/* This is the PCI capability header: */
struct virtio_pci_cap {
__u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */
__u8 cap_next; /* Generic PCI field: next ptr. */
__u8 cap_len; /* Generic PCI field: capability length */
__u8 cfg_type; /* Identifies the structure. */
__u8 bar; /* Where to find it. */
__u8 padding[3]; /* Pad to full dword. */
__le32 offset; /* Offset within bar. */
__le32 length; /* Length of the structure, in bytes. */
};
struct virtio_pci_notify_cap {
struct virtio_pci_cap cap;
__le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
};
/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
struct virtio_pci_common_cfg {
/* About the whole device. */
__le32 device_feature_select; /* read-write */
__le32 device_feature; /* read-only */
__le32 guest_feature_select; /* read-write */
__le32 guest_feature; /* read-write */
__le16 msix_config; /* read-write */
__le16 num_queues; /* read-only */
__u8 device_status; /* read-write */
__u8 config_generation; /* read-only */
/* About a specific virtqueue. */
__le16 queue_select; /* read-write */
__le16 queue_size; /* read-write, power of 2. */
__le16 queue_msix_vector; /* read-write */
__le16 queue_enable; /* read-write */
__le16 queue_notify_off; /* read-only */
__le32 queue_desc_lo; /* read-write */
__le32 queue_desc_hi; /* read-write */
__le32 queue_avail_lo; /* read-write */
__le32 queue_avail_hi; /* read-write */
__le32 queue_used_lo; /* read-write */
__le32 queue_used_hi; /* read-write */
};
/* Macro versions of offsets for the Old Timers! */
#define VIRTIO_PCI_CAP_VNDR 0
#define VIRTIO_PCI_CAP_NEXT 1
#define VIRTIO_PCI_CAP_LEN 2
#define VIRTIO_PCI_CAP_CFG_TYPE 3
#define VIRTIO_PCI_CAP_BAR 4
#define VIRTIO_PCI_CAP_OFFSET 8
#define VIRTIO_PCI_CAP_LENGTH 12
#define VIRTIO_PCI_NOTIFY_CAP_MULT 16
#define VIRTIO_PCI_COMMON_DFSELECT 0
#define VIRTIO_PCI_COMMON_DF 4
#define VIRTIO_PCI_COMMON_GFSELECT 8
#define VIRTIO_PCI_COMMON_GF 12
#define VIRTIO_PCI_COMMON_MSIX 16
#define VIRTIO_PCI_COMMON_NUMQ 18
#define VIRTIO_PCI_COMMON_STATUS 20
#define VIRTIO_PCI_COMMON_CFGGENERATION 21
#define VIRTIO_PCI_COMMON_Q_SELECT 22
#define VIRTIO_PCI_COMMON_Q_SIZE 24
#define VIRTIO_PCI_COMMON_Q_MSIX 26
#define VIRTIO_PCI_COMMON_Q_ENABLE 28
#define VIRTIO_PCI_COMMON_Q_NOFF 30
#define VIRTIO_PCI_COMMON_Q_DESCLO 32
#define VIRTIO_PCI_COMMON_Q_DESCHI 36
#define VIRTIO_PCI_COMMON_Q_AVAILLO 40
#define VIRTIO_PCI_COMMON_Q_AVAILHI 44
#define VIRTIO_PCI_COMMON_Q_USEDLO 48
#define VIRTIO_PCI_COMMON_Q_USEDHI 52
#endif /* VIRTIO_PCI_NO_MODERN */
#endif