mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 09:36:25 +00:00
82af8ce84e
This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ whitespace, style)
73 lines
2.2 KiB
C
73 lines
2.2 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
|
|
#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
|