blob: b976d968e793683a22a6d6c7f213763863ef0bd0 [file] [log] [blame]
* Virtio PCI driver - APIs for common functionality for all device versions
* 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
* Copyright Red Hat, Inc. 2014
* Authors:
* Anthony Liguori <>
* Rusty Russell <>
* Michael S. Tsirkin <>
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
#include <linux/module.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_pci.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
struct virtio_pci_vq_info {
/* the actual virtqueue */
struct virtqueue *vq;
/* the number of entries in the queue */
int num;
/* the virtual address of the ring queue */
void *queue;
/* the list node for the virtqueues list */
struct list_head node;
/* MSI-X vector (or none) */
unsigned msix_vector;
/* Our device structure */
struct virtio_pci_device {
struct virtio_device vdev;
struct pci_dev *pci_dev;
/* In legacy mode, these two point to within ->legacy. */
/* Where to read and clear interrupt */
u8 __iomem *isr;
/* Modern only fields */
/* The IO mapping for the PCI config space (non-legacy mode) */
struct virtio_pci_common_cfg __iomem *common;
/* Device-specific data (non-legacy mode) */
void __iomem *device;
/* Base of vq notifications (non-legacy mode). */
void __iomem *notify_base;
/* So we can sanity-check accesses. */
size_t notify_len;
size_t device_len;
/* Capability for when we need to map notifications per-vq. */
int notify_map_cap;
/* Multiply queue_notify_off by this value. (non-legacy mode). */
u32 notify_offset_multiplier;
int modern_bars;
/* Legacy only field */
/* the IO mapping for the PCI config space */
void __iomem *ioaddr;
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
/* array of all queues for house-keeping */
struct virtio_pci_vq_info **vqs;
/* MSI-X support */
int msix_enabled;
int intx_enabled;
struct msix_entry *msix_entries;
cpumask_var_t *msix_affinity_masks;
/* Name strings for interrupts. This size should be enough,
* and I'm too lazy to allocate each name separately. */
char (*msix_names)[256];
/* Number of available vectors */
unsigned msix_vectors;
/* Vectors allocated, excluding per-vq vectors if any */
unsigned msix_used_vectors;
/* Whether we have vector per vq */
bool per_vq_vectors;
struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
struct virtio_pci_vq_info *info,
unsigned idx,
void (*callback)(struct virtqueue *vq),
const char *name,
u16 msix_vec);
void (*del_vq)(struct virtio_pci_vq_info *info);
u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
/* Constants for MSI-X */
/* Use first vector for configuration changes, second and the rest for
* virtqueues Thus, we need at least 2 vectors for MSI. */
enum {
/* Convert a generic virtio device to our structure */
static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
return container_of(vdev, struct virtio_pci_device, vdev);
/* wait for pending irq handlers */
void vp_synchronize_vectors(struct virtio_device *vdev);
/* the notify function used when creating a virt queue */
bool vp_notify(struct virtqueue *vq);
/* the config->del_vqs() implementation */
void vp_del_vqs(struct virtio_device *vdev);
/* the config->find_vqs() implementation */
int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
const char *names[]);
const char *vp_bus_name(struct virtio_device *vdev);
/* Setup the affinity for a virtqueue:
* - force the affinity for per vq vector
* - OR over all affinities for shared MSI
* - ignore the affinity request if we're using INTX
int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
int virtio_pci_legacy_probe(struct virtio_pci_device *);
void virtio_pci_legacy_remove(struct virtio_pci_device *);
static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
return -ENODEV;
static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
int virtio_pci_modern_probe(struct virtio_pci_device *);
void virtio_pci_modern_remove(struct virtio_pci_device *);