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/virtio_config.h> 43 44/* A 32-bit r/o bitmask of the features supported by the host */ 45#define VIRTIO_PCI_HOST_FEATURES 0 46 47/* A 32-bit r/w bitmask of features activated by the guest */ 48#define VIRTIO_PCI_GUEST_FEATURES 4 49 50/* A 32-bit r/w PFN for the currently selected queue */ 51#define VIRTIO_PCI_QUEUE_PFN 8 52 53/* A 16-bit r/o queue size for the currently selected queue */ 54#define VIRTIO_PCI_QUEUE_NUM 12 55 56/* A 16-bit r/w queue selector */ 57#define VIRTIO_PCI_QUEUE_SEL 14 58 59/* A 16-bit r/w queue notifier */ 60#define VIRTIO_PCI_QUEUE_NOTIFY 16 61 62/* An 8-bit device status register. */ 63#define VIRTIO_PCI_STATUS 18 64 65/* An 8-bit r/o interrupt status register. Reading the value will return the 66 * current contents of the ISR and will also clear it. This is effectively 67 * a read-and-acknowledge. */ 68#define VIRTIO_PCI_ISR 19 69 70/* The bit of the ISR which indicates a device configuration change. */ 71#define VIRTIO_PCI_ISR_CONFIG 0x2 72 73/* MSI-X registers: only enabled if MSI-X is enabled. */ 74/* A 16-bit vector for configuration changes. */ 75#define VIRTIO_MSI_CONFIG_VECTOR 20 76/* A 16-bit vector for selected queue notifications. */ 77#define VIRTIO_MSI_QUEUE_VECTOR 22 78/* Vector value used to disable MSI for queue */ 79#define VIRTIO_MSI_NO_VECTOR 0xffff 80 81/* The remaining space is defined by each driver as the per-driver 82 * configuration space */ 83#define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20) 84/* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */ 85#define VIRTIO_PCI_CONFIG(dev) VIRTIO_PCI_CONFIG_OFF((dev)->msix_enabled) 86 87/* Virtio ABI version, this must match exactly */ 88#define VIRTIO_PCI_ABI_VERSION 0 89 90/* How many bits to shift physical queue address written to QUEUE_PFN. 91 * 12 is historical, and due to x86 page size. */ 92#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 93 94/* The alignment to use between consumer and producer parts of vring. 95 * x86 pagesize again. */ 96#define VIRTIO_PCI_VRING_ALIGN 4096 97#endif 98