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 /* The remaining space is defined by each driver as the per-driver 51 * configuration space */ 52 #define VIRTIO_PCI_CONFIG 20 53 54 /* Virtio ABI version, this must match exactly */ 55 #define VIRTIO_PCI_ABI_VERSION 0 56 57 /* How many bits to shift physical queue address written to QUEUE_PFN. 58 * 12 is historical, and due to x86 page size. */ 59 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 60 61 /* The alignment to use between consumer and producer parts of vring. 62 * x86 pagesize again. */ 63 #define VIRTIO_PCI_VRING_ALIGN 4096 64 #endif 65