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/* SPDX-License-Identifier: GPL-2.0-or-later */
* 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 <>
#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/virtio_pci_legacy.h>
#include <linux/virtio_pci_modern.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
struct virtio_pci_vq_info {
/* the actual virtqueue */
struct virtqueue *vq;
/* 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;
struct virtio_pci_legacy_device ldev;
struct virtio_pci_modern_device mdev;
bool is_legacy;
/* Where to read and clear interrupt */
u8 __iomem *isr;
/* 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;
bool intx_soft_enabled;
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,
bool ctx,
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);
/* disable irq handlers */
void vp_disable_cbs(struct virtio_device *vdev);
/* enable irq handlers */
void vp_enable_cbs(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 * const names[], const bool *ctx,
struct irq_affinity *desc);
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, const struct cpumask *cpu_mask);
const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
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 *);