linux/drivers/virtio/virtio_pci_common.h
Andy Lutomirski 7a5589b240 virtio_pci: Use the DMA API if enabled
This switches to vring_create_virtqueue, simplifying the driver and
adding DMA API support.

This fixes virtio-pci on platforms and busses that have IOMMUs.  This
will break the experimental QEMU Q35 IOMMU support until QEMU is
fixed.  In exchange, it fixes physical virtio hardware as well as
virtio-pci running under Xen.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-02 17:01:58 +02:00

162 lines
4.6 KiB
C

#ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
#define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
/*
* 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 <aliguori@us.ibm.com>
* Rusty Russell <rusty@rustcorp.com.au>
* Michael S. Tsirkin <mst@redhat.com>
*
* 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 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 {
VP_MSIX_CONFIG_VECTOR = 0,
VP_MSIX_VQ_VECTOR = 1,
};
/* 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 * const 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);
#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
int virtio_pci_legacy_probe(struct virtio_pci_device *);
void virtio_pci_legacy_remove(struct virtio_pci_device *);
#else
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)
{
}
#endif
int virtio_pci_modern_probe(struct virtio_pci_device *);
void virtio_pci_modern_remove(struct virtio_pci_device *);
#endif