mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 18:30:06 +00:00
![Christoph Hellwig](/assets/img/avatar_default.png)
This basically passed up the pci_irq_get_affinity information through virtio through an optional get_vq_affinity method. It is only implemented by the PCI backend for now, and only when we use per-virtqueue IRQs. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
515 lines
13 KiB
C
515 lines
13 KiB
C
/*
|
|
* Virtio PCI driver - 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 "virtio_pci_common.h"
|
|
|
|
static bool force_legacy = false;
|
|
|
|
#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
|
|
module_param(force_legacy, bool, 0444);
|
|
MODULE_PARM_DESC(force_legacy,
|
|
"Force legacy mode for transitional virtio 1 devices");
|
|
#endif
|
|
|
|
/* wait for pending irq handlers */
|
|
void vp_synchronize_vectors(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
int i;
|
|
|
|
synchronize_irq(pci_irq_vector(vp_dev->pci_dev, 0));
|
|
for (i = 1; i < vp_dev->msix_vectors; i++)
|
|
synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));
|
|
}
|
|
|
|
/* the notify function used when creating a virt queue */
|
|
bool vp_notify(struct virtqueue *vq)
|
|
{
|
|
/* we write the queue's selector into the notification register to
|
|
* signal the other end */
|
|
iowrite16(vq->index, (void __iomem *)vq->priv);
|
|
return true;
|
|
}
|
|
|
|
/* Handle a configuration change: Tell driver if it wants to know. */
|
|
static irqreturn_t vp_config_changed(int irq, void *opaque)
|
|
{
|
|
struct virtio_pci_device *vp_dev = opaque;
|
|
|
|
virtio_config_changed(&vp_dev->vdev);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/* Notify all virtqueues on an interrupt. */
|
|
static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
|
|
{
|
|
struct virtio_pci_device *vp_dev = opaque;
|
|
irqreturn_t ret = IRQ_NONE;
|
|
struct virtqueue *vq;
|
|
|
|
list_for_each_entry(vq, &vp_dev->vdev.vqs, list) {
|
|
if (vq->callback && vring_interrupt(irq, vq) == IRQ_HANDLED)
|
|
ret = IRQ_HANDLED;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* 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;
|
|
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->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)
|
|
vp_config_changed(irq, opaque);
|
|
|
|
return vp_vring_interrupt(irq, opaque);
|
|
}
|
|
|
|
static void vp_remove_vqs(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
struct virtqueue *vq, *n;
|
|
|
|
list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
|
|
if (vp_dev->msix_vector_map) {
|
|
int v = vp_dev->msix_vector_map[vq->index];
|
|
|
|
if (v != VIRTIO_MSI_NO_VECTOR)
|
|
free_irq(pci_irq_vector(vp_dev->pci_dev, v),
|
|
vq);
|
|
}
|
|
vp_dev->del_vq(vq);
|
|
}
|
|
}
|
|
|
|
/* the config->del_vqs() implementation */
|
|
void vp_del_vqs(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
int i;
|
|
|
|
if (WARN_ON_ONCE(list_empty_careful(&vdev->vqs)))
|
|
return;
|
|
|
|
vp_remove_vqs(vdev);
|
|
|
|
if (vp_dev->pci_dev->msix_enabled) {
|
|
for (i = 0; i < vp_dev->msix_vectors; i++)
|
|
free_cpumask_var(vp_dev->msix_affinity_masks[i]);
|
|
|
|
/* Disable the vector used for configuration */
|
|
vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
|
|
|
|
kfree(vp_dev->msix_affinity_masks);
|
|
kfree(vp_dev->msix_names);
|
|
kfree(vp_dev->msix_vector_map);
|
|
}
|
|
|
|
free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
|
|
pci_free_irq_vectors(vp_dev->pci_dev);
|
|
}
|
|
|
|
static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
|
|
struct virtqueue *vqs[], vq_callback_t *callbacks[],
|
|
const char * const names[], struct irq_affinity *desc)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
const char *name = dev_name(&vp_dev->vdev.dev);
|
|
int i, err = -ENOMEM, allocated_vectors, nvectors;
|
|
unsigned flags = PCI_IRQ_MSIX;
|
|
bool shared = false;
|
|
u16 msix_vec;
|
|
|
|
if (desc) {
|
|
flags |= PCI_IRQ_AFFINITY;
|
|
desc->pre_vectors++; /* virtio config vector */
|
|
}
|
|
|
|
nvectors = 1;
|
|
for (i = 0; i < nvqs; i++)
|
|
if (callbacks[i])
|
|
nvectors++;
|
|
|
|
/* Try one vector per queue first. */
|
|
err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
|
|
nvectors, flags, desc);
|
|
if (err < 0) {
|
|
/* Fallback to one vector for config, one shared for queues. */
|
|
shared = true;
|
|
err = pci_alloc_irq_vectors(vp_dev->pci_dev, 2, 2,
|
|
PCI_IRQ_MSIX);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
if (err < 0)
|
|
return err;
|
|
|
|
vp_dev->msix_vectors = nvectors;
|
|
vp_dev->msix_names = kmalloc_array(nvectors,
|
|
sizeof(*vp_dev->msix_names), GFP_KERNEL);
|
|
if (!vp_dev->msix_names)
|
|
goto out_free_irq_vectors;
|
|
|
|
vp_dev->msix_affinity_masks = kcalloc(nvectors,
|
|
sizeof(*vp_dev->msix_affinity_masks), GFP_KERNEL);
|
|
if (!vp_dev->msix_affinity_masks)
|
|
goto out_free_msix_names;
|
|
|
|
for (i = 0; i < nvectors; ++i) {
|
|
if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
|
|
GFP_KERNEL))
|
|
goto out_free_msix_affinity_masks;
|
|
}
|
|
|
|
/* Set the vector used for configuration */
|
|
snprintf(vp_dev->msix_names[0], sizeof(*vp_dev->msix_names),
|
|
"%s-config", name);
|
|
err = request_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_config_changed,
|
|
0, vp_dev->msix_names[0], vp_dev);
|
|
if (err)
|
|
goto out_free_msix_affinity_masks;
|
|
|
|
/* Verify we had enough resources to assign the vector */
|
|
if (vp_dev->config_vector(vp_dev, 0) == VIRTIO_MSI_NO_VECTOR) {
|
|
err = -EBUSY;
|
|
goto out_free_config_irq;
|
|
}
|
|
|
|
vp_dev->msix_vector_map = kmalloc_array(nvqs,
|
|
sizeof(*vp_dev->msix_vector_map), GFP_KERNEL);
|
|
if (!vp_dev->msix_vector_map)
|
|
goto out_disable_config_irq;
|
|
|
|
allocated_vectors = 1; /* vector 0 is the config interrupt */
|
|
for (i = 0; i < nvqs; ++i) {
|
|
if (!names[i]) {
|
|
vqs[i] = NULL;
|
|
continue;
|
|
}
|
|
|
|
if (callbacks[i])
|
|
msix_vec = allocated_vectors;
|
|
else
|
|
msix_vec = VIRTIO_MSI_NO_VECTOR;
|
|
|
|
vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
|
|
msix_vec);
|
|
if (IS_ERR(vqs[i])) {
|
|
err = PTR_ERR(vqs[i]);
|
|
goto out_remove_vqs;
|
|
}
|
|
|
|
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
|
|
vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
|
|
continue;
|
|
}
|
|
|
|
snprintf(vp_dev->msix_names[i + 1],
|
|
sizeof(*vp_dev->msix_names), "%s-%s",
|
|
dev_name(&vp_dev->vdev.dev), names[i]);
|
|
err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
|
|
vring_interrupt, IRQF_SHARED,
|
|
vp_dev->msix_names[i + 1], vqs[i]);
|
|
if (err) {
|
|
/* don't free this irq on error */
|
|
vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
|
|
goto out_remove_vqs;
|
|
}
|
|
vp_dev->msix_vector_map[i] = msix_vec;
|
|
|
|
/*
|
|
* Use a different vector for each queue if they are available,
|
|
* else share the same vector for all VQs.
|
|
*/
|
|
if (!shared)
|
|
allocated_vectors++;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_remove_vqs:
|
|
vp_remove_vqs(vdev);
|
|
kfree(vp_dev->msix_vector_map);
|
|
out_disable_config_irq:
|
|
vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
|
|
out_free_config_irq:
|
|
free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
|
|
out_free_msix_affinity_masks:
|
|
for (i = 0; i < nvectors; i++) {
|
|
if (vp_dev->msix_affinity_masks[i])
|
|
free_cpumask_var(vp_dev->msix_affinity_masks[i]);
|
|
}
|
|
kfree(vp_dev->msix_affinity_masks);
|
|
out_free_msix_names:
|
|
kfree(vp_dev->msix_names);
|
|
out_free_irq_vectors:
|
|
pci_free_irq_vectors(vp_dev->pci_dev);
|
|
return err;
|
|
}
|
|
|
|
static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
|
|
struct virtqueue *vqs[], vq_callback_t *callbacks[],
|
|
const char * const names[])
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
int i, err;
|
|
|
|
err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
|
|
dev_name(&vdev->dev), vp_dev);
|
|
if (err)
|
|
return err;
|
|
|
|
for (i = 0; i < nvqs; ++i) {
|
|
if (!names[i]) {
|
|
vqs[i] = NULL;
|
|
continue;
|
|
}
|
|
vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
|
|
VIRTIO_MSI_NO_VECTOR);
|
|
if (IS_ERR(vqs[i])) {
|
|
err = PTR_ERR(vqs[i]);
|
|
goto out_remove_vqs;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_remove_vqs:
|
|
vp_remove_vqs(vdev);
|
|
free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
|
|
return err;
|
|
}
|
|
|
|
/* 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[], struct irq_affinity *desc)
|
|
{
|
|
int err;
|
|
|
|
err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, desc);
|
|
if (!err)
|
|
return 0;
|
|
return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names);
|
|
}
|
|
|
|
const char *vp_bus_name(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
|
|
return pci_name(vp_dev->pci_dev);
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
struct virtio_device *vdev = vq->vdev;
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
|
|
if (!vq->callback)
|
|
return -EINVAL;
|
|
|
|
if (vp_dev->pci_dev->msix_enabled) {
|
|
int vec = vp_dev->msix_vector_map[vq->index];
|
|
struct cpumask *mask = vp_dev->msix_affinity_masks[vec];
|
|
unsigned int irq = pci_irq_vector(vp_dev->pci_dev, vec);
|
|
|
|
if (cpu == -1)
|
|
irq_set_affinity_hint(irq, NULL);
|
|
else {
|
|
cpumask_clear(mask);
|
|
cpumask_set_cpu(cpu, mask);
|
|
irq_set_affinity_hint(irq, mask);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index)
|
|
{
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
unsigned int *map = vp_dev->msix_vector_map;
|
|
|
|
if (!map || map[index] == VIRTIO_MSI_NO_VECTOR)
|
|
return NULL;
|
|
|
|
return pci_irq_get_affinity(vp_dev->pci_dev, map[index]);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int virtio_pci_freeze(struct device *dev)
|
|
{
|
|
struct pci_dev *pci_dev = to_pci_dev(dev);
|
|
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
|
|
int ret;
|
|
|
|
ret = virtio_device_freeze(&vp_dev->vdev);
|
|
|
|
if (!ret)
|
|
pci_disable_device(pci_dev);
|
|
return ret;
|
|
}
|
|
|
|
static int virtio_pci_restore(struct device *dev)
|
|
{
|
|
struct pci_dev *pci_dev = to_pci_dev(dev);
|
|
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
|
|
int ret;
|
|
|
|
ret = pci_enable_device(pci_dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
pci_set_master(pci_dev);
|
|
return virtio_device_restore(&vp_dev->vdev);
|
|
}
|
|
|
|
static const struct dev_pm_ops virtio_pci_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
|
|
};
|
|
#endif
|
|
|
|
|
|
/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
|
|
static const struct pci_device_id virtio_pci_id_table[] = {
|
|
{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
|
|
{ 0 }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
|
|
|
|
static void virtio_pci_release_dev(struct device *_d)
|
|
{
|
|
struct virtio_device *vdev = dev_to_virtio(_d);
|
|
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
|
|
|
|
/* As struct device is a kobject, it's not safe to
|
|
* free the memory (including the reference counter itself)
|
|
* until it's release callback. */
|
|
kfree(vp_dev);
|
|
}
|
|
|
|
static int virtio_pci_probe(struct pci_dev *pci_dev,
|
|
const struct pci_device_id *id)
|
|
{
|
|
struct virtio_pci_device *vp_dev;
|
|
int rc;
|
|
|
|
/* allocate our structure and fill it out */
|
|
vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
|
|
if (!vp_dev)
|
|
return -ENOMEM;
|
|
|
|
pci_set_drvdata(pci_dev, vp_dev);
|
|
vp_dev->vdev.dev.parent = &pci_dev->dev;
|
|
vp_dev->vdev.dev.release = virtio_pci_release_dev;
|
|
vp_dev->pci_dev = pci_dev;
|
|
|
|
/* enable the device */
|
|
rc = pci_enable_device(pci_dev);
|
|
if (rc)
|
|
goto err_enable_device;
|
|
|
|
if (force_legacy) {
|
|
rc = virtio_pci_legacy_probe(vp_dev);
|
|
/* Also try modern mode if we can't map BAR0 (no IO space). */
|
|
if (rc == -ENODEV || rc == -ENOMEM)
|
|
rc = virtio_pci_modern_probe(vp_dev);
|
|
if (rc)
|
|
goto err_probe;
|
|
} else {
|
|
rc = virtio_pci_modern_probe(vp_dev);
|
|
if (rc == -ENODEV)
|
|
rc = virtio_pci_legacy_probe(vp_dev);
|
|
if (rc)
|
|
goto err_probe;
|
|
}
|
|
|
|
pci_set_master(pci_dev);
|
|
|
|
rc = register_virtio_device(&vp_dev->vdev);
|
|
if (rc)
|
|
goto err_register;
|
|
|
|
return 0;
|
|
|
|
err_register:
|
|
if (vp_dev->ioaddr)
|
|
virtio_pci_legacy_remove(vp_dev);
|
|
else
|
|
virtio_pci_modern_remove(vp_dev);
|
|
err_probe:
|
|
pci_disable_device(pci_dev);
|
|
err_enable_device:
|
|
kfree(vp_dev);
|
|
return rc;
|
|
}
|
|
|
|
static void virtio_pci_remove(struct pci_dev *pci_dev)
|
|
{
|
|
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
|
|
struct device *dev = get_device(&vp_dev->vdev.dev);
|
|
|
|
unregister_virtio_device(&vp_dev->vdev);
|
|
|
|
if (vp_dev->ioaddr)
|
|
virtio_pci_legacy_remove(vp_dev);
|
|
else
|
|
virtio_pci_modern_remove(vp_dev);
|
|
|
|
pci_disable_device(pci_dev);
|
|
put_device(dev);
|
|
}
|
|
|
|
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_SLEEP
|
|
.driver.pm = &virtio_pci_pm_ops,
|
|
#endif
|
|
};
|
|
|
|
module_pci_driver(virtio_pci_driver);
|
|
|
|
MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
|
|
MODULE_DESCRIPTION("virtio-pci");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION("1");
|