mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Anthony Liguori](/assets/img/avatar_default.png)
As Avi pointed out, as we continue to massage the virtio PCI ABI, we can make things a little more friendly to users by utilizing the PCI revision field to indicate which version of the ABI we're using. This is a hard ABI version and incrementing it will cause the guest driver to break. This is the necessary changes to virtio_pci to support this. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
446 lines
12 KiB
C
446 lines
12 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 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/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>
|
|
|
|
MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
|
|
MODULE_DESCRIPTION("virtio-pci");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION("1");
|
|
|
|
/* Our device structure */
|
|
struct virtio_pci_device
|
|
{
|
|
struct virtio_device vdev;
|
|
struct pci_dev *pci_dev;
|
|
|
|
/* the IO mapping for the PCI config space */
|
|
void *ioaddr;
|
|
|
|
/* a list of queues so we can dispatch IRQs */
|
|
spinlock_t lock;
|
|
struct list_head virtqueues;
|
|
};
|
|
|
|
struct virtio_pci_vq_info
|
|
{
|
|
/* the actual virtqueue */
|
|
struct virtqueue *vq;
|
|
|
|
/* the number of entries in the queue */
|
|
int num;
|
|
|
|
/* the index of the queue */
|
|
int queue_index;
|
|
|
|
/* the virtual address of the ring queue */
|
|
void *queue;
|
|
|
|
/* the list node for the virtqueues list */
|
|
struct list_head node;
|
|
};
|
|
|
|
/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
|
|
static struct pci_device_id virtio_pci_id_table[] = {
|
|
{ 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
|
|
{ 0 },
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
|
|
|
|
/* A PCI device has it's own struct device and so does a virtio device so
|
|
* we create a place for the virtio devices to show up in sysfs. I think it
|
|
* would make more sense for virtio to not insist on having it's own device. */
|
|
static struct device virtio_pci_root = {
|
|
.parent = NULL,
|
|
.bus_id = "virtio-pci",
|
|
};
|
|
|
|
/* Unique numbering for devices under the kvm root */
|
|
static unsigned int dev_index;
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/* virtio config->feature() implementation */
|
|
static bool vp_feature(struct virtio_device *vdev, unsigned bit)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
u32 mask;
|
|
|
|
/* Since this function is supposed to have the side effect of
|
|
* enabling a queried feature, we simulate that by doing a read
|
|
* from the host feature bitmask and then writing to the guest
|
|
* feature bitmask */
|
|
mask = ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
|
|
if (mask & (1 << bit)) {
|
|
mask |= (1 << bit);
|
|
iowrite32(mask, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
|
|
}
|
|
|
|
return !!(mask & (1 << bit));
|
|
}
|
|
|
|
/* virtio config->get() implementation */
|
|
static void vp_get(struct virtio_device *vdev, unsigned offset,
|
|
void *buf, unsigned len)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
void *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
|
|
u8 *ptr = buf;
|
|
int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
ptr[i] = ioread8(ioaddr + i);
|
|
}
|
|
|
|
/* the config->set() implementation. it's symmetric to the config->get()
|
|
* implementation */
|
|
static void vp_set(struct virtio_device *vdev, unsigned offset,
|
|
const void *buf, unsigned len)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
void *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
|
|
const u8 *ptr = buf;
|
|
int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
iowrite8(ptr[i], ioaddr + i);
|
|
}
|
|
|
|
/* config->{get,set}_status() implementations */
|
|
static u8 vp_get_status(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
|
|
}
|
|
|
|
static void vp_set_status(struct virtio_device *vdev, u8 status)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
/* We should never be setting status to 0. */
|
|
BUG_ON(status == 0);
|
|
return iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
|
|
}
|
|
|
|
static void vp_reset(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
/* 0 status means a reset. */
|
|
return iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
|
|
}
|
|
|
|
/* the notify function used when creating a virt queue */
|
|
static void vp_notify(struct virtqueue *vq)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
|
|
struct virtio_pci_vq_info *info = vq->priv;
|
|
|
|
/* we write the queue's selector into the notification register to
|
|
* signal the other end */
|
|
iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
|
|
}
|
|
|
|
/* A small wrapper to also acknowledge the interrupt when it's handled.
|
|
* I really need an EIO hook for the vring so I can ack the interrupt once we
|
|
* know that we'll be handling the IRQ but before we invoke the callback since
|
|
* the callback may notify the host which results in the host attempting to
|
|
* raise an interrupt that we would then mask once we acknowledged the
|
|
* interrupt. */
|
|
static irqreturn_t vp_interrupt(int irq, void *opaque)
|
|
{
|
|
struct virtio_pci_device *vp_dev = opaque;
|
|
struct virtio_pci_vq_info *info;
|
|
irqreturn_t ret = IRQ_NONE;
|
|
u8 isr;
|
|
|
|
/* reading the ISR has the effect of also clearing it so it's very
|
|
* important to save off the value. */
|
|
isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
|
|
|
|
/* It's definitely not us if the ISR was not high */
|
|
if (!isr)
|
|
return IRQ_NONE;
|
|
|
|
/* Configuration change? Tell driver if it wants to know. */
|
|
if (isr & VIRTIO_PCI_ISR_CONFIG) {
|
|
struct virtio_driver *drv;
|
|
drv = container_of(vp_dev->vdev.dev.driver,
|
|
struct virtio_driver, driver);
|
|
|
|
if (drv->config_changed)
|
|
drv->config_changed(&vp_dev->vdev);
|
|
}
|
|
|
|
spin_lock(&vp_dev->lock);
|
|
list_for_each_entry(info, &vp_dev->virtqueues, node) {
|
|
if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
|
|
ret = IRQ_HANDLED;
|
|
}
|
|
spin_unlock(&vp_dev->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* the config->find_vq() implementation */
|
|
static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
|
|
void (*callback)(struct virtqueue *vq))
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
struct virtio_pci_vq_info *info;
|
|
struct virtqueue *vq;
|
|
u16 num;
|
|
int err;
|
|
|
|
/* Select the queue we're interested in */
|
|
iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
|
|
|
|
/* Check if queue is either not available or already active. */
|
|
num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
|
|
if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
/* allocate and fill out our structure the represents an active
|
|
* queue */
|
|
info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
|
|
if (!info)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
info->queue_index = index;
|
|
info->num = num;
|
|
|
|
info->queue = kzalloc(PAGE_ALIGN(vring_size(num,PAGE_SIZE)), GFP_KERNEL);
|
|
if (info->queue == NULL) {
|
|
err = -ENOMEM;
|
|
goto out_info;
|
|
}
|
|
|
|
/* activate the queue */
|
|
iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT,
|
|
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
|
|
|
|
/* create the vring */
|
|
vq = vring_new_virtqueue(info->num, vdev, info->queue,
|
|
vp_notify, callback);
|
|
if (!vq) {
|
|
err = -ENOMEM;
|
|
goto out_activate_queue;
|
|
}
|
|
|
|
vq->priv = info;
|
|
info->vq = vq;
|
|
|
|
spin_lock(&vp_dev->lock);
|
|
list_add(&info->node, &vp_dev->virtqueues);
|
|
spin_unlock(&vp_dev->lock);
|
|
|
|
return vq;
|
|
|
|
out_activate_queue:
|
|
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
|
|
kfree(info->queue);
|
|
out_info:
|
|
kfree(info);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/* the config->del_vq() implementation */
|
|
static void vp_del_vq(struct virtqueue *vq)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
|
|
struct virtio_pci_vq_info *info = vq->priv;
|
|
|
|
spin_lock(&vp_dev->lock);
|
|
list_del(&info->node);
|
|
spin_unlock(&vp_dev->lock);
|
|
|
|
vring_del_virtqueue(vq);
|
|
|
|
/* Select and deactivate the queue */
|
|
iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
|
|
iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
|
|
|
|
kfree(info->queue);
|
|
kfree(info);
|
|
}
|
|
|
|
static struct virtio_config_ops virtio_pci_config_ops = {
|
|
.feature = vp_feature,
|
|
.get = vp_get,
|
|
.set = vp_set,
|
|
.get_status = vp_get_status,
|
|
.set_status = vp_set_status,
|
|
.reset = vp_reset,
|
|
.find_vq = vp_find_vq,
|
|
.del_vq = vp_del_vq,
|
|
};
|
|
|
|
/* the PCI probing function */
|
|
static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
|
|
const struct pci_device_id *id)
|
|
{
|
|
struct virtio_pci_device *vp_dev;
|
|
int err;
|
|
|
|
/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
|
|
if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
|
|
return -ENODEV;
|
|
|
|
if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
|
|
printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
|
|
VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* allocate our structure and fill it out */
|
|
vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
|
|
if (vp_dev == NULL)
|
|
return -ENOMEM;
|
|
|
|
snprintf(vp_dev->vdev.dev.bus_id, BUS_ID_SIZE, "virtio%d", dev_index);
|
|
vp_dev->vdev.index = dev_index;
|
|
dev_index++;
|
|
|
|
vp_dev->vdev.dev.parent = &virtio_pci_root;
|
|
vp_dev->vdev.config = &virtio_pci_config_ops;
|
|
vp_dev->pci_dev = pci_dev;
|
|
INIT_LIST_HEAD(&vp_dev->virtqueues);
|
|
spin_lock_init(&vp_dev->lock);
|
|
|
|
/* enable the device */
|
|
err = pci_enable_device(pci_dev);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = pci_request_regions(pci_dev, "virtio-pci");
|
|
if (err)
|
|
goto out_enable_device;
|
|
|
|
vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
|
|
if (vp_dev->ioaddr == NULL)
|
|
goto out_req_regions;
|
|
|
|
pci_set_drvdata(pci_dev, vp_dev);
|
|
|
|
/* we use the subsystem vendor/device id as the virtio vendor/device
|
|
* id. this allows us to use the same PCI vendor/device id for all
|
|
* virtio devices and to identify the particular virtio driver by
|
|
* the subsytem ids */
|
|
vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
|
|
vp_dev->vdev.id.device = pci_dev->subsystem_device;
|
|
|
|
/* register a handler for the queue with the PCI device's interrupt */
|
|
err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
|
|
vp_dev->vdev.dev.bus_id, vp_dev);
|
|
if (err)
|
|
goto out_set_drvdata;
|
|
|
|
/* finally register the virtio device */
|
|
err = register_virtio_device(&vp_dev->vdev);
|
|
if (err)
|
|
goto out_req_irq;
|
|
|
|
return 0;
|
|
|
|
out_req_irq:
|
|
free_irq(pci_dev->irq, vp_dev);
|
|
out_set_drvdata:
|
|
pci_set_drvdata(pci_dev, NULL);
|
|
pci_iounmap(pci_dev, vp_dev->ioaddr);
|
|
out_req_regions:
|
|
pci_release_regions(pci_dev);
|
|
out_enable_device:
|
|
pci_disable_device(pci_dev);
|
|
out:
|
|
kfree(vp_dev);
|
|
return err;
|
|
}
|
|
|
|
static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
|
|
|
|
free_irq(pci_dev->irq, vp_dev);
|
|
pci_set_drvdata(pci_dev, NULL);
|
|
pci_iounmap(pci_dev, vp_dev->ioaddr);
|
|
pci_release_regions(pci_dev);
|
|
pci_disable_device(pci_dev);
|
|
kfree(vp_dev);
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
|
|
{
|
|
pci_save_state(pci_dev);
|
|
pci_set_power_state(pci_dev, PCI_D3hot);
|
|
return 0;
|
|
}
|
|
|
|
static int virtio_pci_resume(struct pci_dev *pci_dev)
|
|
{
|
|
pci_restore_state(pci_dev);
|
|
pci_set_power_state(pci_dev, PCI_D0);
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static struct pci_driver virtio_pci_driver = {
|
|
.name = "virtio-pci",
|
|
.id_table = virtio_pci_id_table,
|
|
.probe = virtio_pci_probe,
|
|
.remove = virtio_pci_remove,
|
|
#ifdef CONFIG_PM
|
|
.suspend = virtio_pci_suspend,
|
|
.resume = virtio_pci_resume,
|
|
#endif
|
|
};
|
|
|
|
static int __init virtio_pci_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = device_register(&virtio_pci_root);
|
|
if (err)
|
|
return err;
|
|
|
|
err = pci_register_driver(&virtio_pci_driver);
|
|
if (err)
|
|
device_unregister(&virtio_pci_root);
|
|
|
|
return err;
|
|
}
|
|
|
|
module_init(virtio_pci_init);
|
|
|
|
static void __exit virtio_pci_exit(void)
|
|
{
|
|
device_unregister(&virtio_pci_root);
|
|
pci_unregister_driver(&virtio_pci_driver);
|
|
}
|
|
|
|
module_exit(virtio_pci_exit);
|