|  | /* | 
|  | * 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/virtio_config.h> | 
|  |  | 
|  | /* 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 | 
|  |  | 
|  | /* The bit of the ISR which indicates a device configuration change. */ | 
|  | #define VIRTIO_PCI_ISR_CONFIG		0x2 | 
|  |  | 
|  | /* 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 | 
|  | /* Vector value used to disable MSI for queue */ | 
|  | #define VIRTIO_MSI_NO_VECTOR            0xffff | 
|  |  | 
|  | /* 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 |