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 16#ifndef _LINUX_VIRTIO_PCI_H 17#define _LINUX_VIRTIO_PCI_H 18 19#include <linux/virtio_config.h> 20 21/* A 32-bit r/o bitmask of the features supported by the host */ 22#define VIRTIO_PCI_HOST_FEATURES 0 23 24/* A 32-bit r/w bitmask of features activated by the guest */ 25#define VIRTIO_PCI_GUEST_FEATURES 4 26 27/* A 32-bit r/w PFN for the currently selected queue */ 28#define VIRTIO_PCI_QUEUE_PFN 8 29 30/* A 16-bit r/o queue size for the currently selected queue */ 31#define VIRTIO_PCI_QUEUE_NUM 12 32 33/* A 16-bit r/w queue selector */ 34#define VIRTIO_PCI_QUEUE_SEL 14 35 36/* A 16-bit r/w queue notifier */ 37#define VIRTIO_PCI_QUEUE_NOTIFY 16 38 39/* An 8-bit device status register. */ 40#define VIRTIO_PCI_STATUS 18 41 42/* An 8-bit r/o interrupt status register. Reading the value will return the 43 * current contents of the ISR and will also clear it. This is effectively 44 * a read-and-acknowledge. */ 45#define VIRTIO_PCI_ISR 19 46 47/* The bit of the ISR which indicates a device configuration change. */ 48#define VIRTIO_PCI_ISR_CONFIG 0x2 49 50/* MSI-X registers: only enabled if MSI-X is enabled. */ 51/* A 16-bit vector for configuration changes. */ 52#define VIRTIO_MSI_CONFIG_VECTOR 20 53/* A 16-bit vector for selected queue notifications. */ 54#define VIRTIO_MSI_QUEUE_VECTOR 22 55/* Vector value used to disable MSI for queue */ 56#define VIRTIO_MSI_NO_VECTOR 0xffff 57 58/* The remaining space is defined by each driver as the per-driver 59 * configuration space */ 60#define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20) 61 62/* Virtio ABI version, this must match exactly */ 63#define VIRTIO_PCI_ABI_VERSION 0 64 65/* How many bits to shift physical queue address written to QUEUE_PFN. 66 * 12 is historical, and due to x86 page size. */ 67#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 68 69/* The alignment to use between consumer and producer parts of vring. 70 * x86 pagesize again. */ 71#define VIRTIO_PCI_VRING_ALIGN 4096 72#endif 73