include/uapi/linux/virtio_pci.h - virt/kvm/kvm - Git at Google

 /*
  * 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  <aliguori@us.ibm.com>
  *
  * 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_OFF(msix_enabled)	((msix_enabled) ? 24 : 20)
 /* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
 #define VIRTIO_PCI_CONFIG(dev)	VIRTIO_PCI_CONFIG_OFF((dev)->msix_enabled)

 /* 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 */
 };

 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
 struct virtio_pci_cfg_cap {
 	struct virtio_pci_cap cap;
 	__u8 pci_cfg_data[4]; /* Data for BAR access. */
 };

 /* 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
	/*
	* 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 <aliguori@us.ibm.com>
	*
	* 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_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
	/* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
	#define VIRTIO_PCI_CONFIG(dev) VIRTIO_PCI_CONFIG_OFF((dev)->msix_enabled)

	/* 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 */
	};

	/* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
	struct virtio_pci_cfg_cap {
	struct virtio_pci_cap cap;
	__u8 pci_cfg_data[4]; /* Data for BAR access. */
	};

	/* 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