virtio: allow drivers to request IRQ affinity when creating VQs
Add a struct irq_affinity pointer to the find_vqs methods, which if set
is used to tell the PCI layer to create the MSI-X vectors for our I/O
virtqueues with the proper affinity from the start. Compared to after
the fact affinity hints this gives us an instantly working setup and
allows to allocate the irq descritors node-local and avoid interconnect
traffic. Last but not least this will allow blk-mq queues are created
based on the interrupt affinity for storage drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 181793f..36c9c8f 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -413,7 +413,8 @@ static int init_vqs(struct virtio_balloon *vb)
* optionally stat.
*/
nvqs = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2;
- err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names);
+ err = vb->vdev->config->find_vqs(vb->vdev, nvqs, vqs, callbacks, names,
+ NULL);
if (err)
return err;
diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
index 350a2a5..79f1293 100644
--- a/drivers/virtio/virtio_input.c
+++ b/drivers/virtio/virtio_input.c
@@ -173,7 +173,8 @@ static int virtinput_init_vqs(struct virtio_input *vi)
static const char * const names[] = { "events", "status" };
int err;
- err = vi->vdev->config->find_vqs(vi->vdev, 2, vqs, cbs, names);
+ err = vi->vdev->config->find_vqs(vi->vdev, 2, vqs, cbs, names,
+ NULL);
if (err)
return err;
vi->evt = vqs[0];
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 08357d7..78343b8 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -446,7 +446,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
- const char * const names[])
+ const char * const names[],
+ struct irq_affinity *desc)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 822f8e5..7902e92 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -143,22 +143,28 @@ void vp_del_vqs(struct virtio_device *vdev)
static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[], vq_callback_t *callbacks[],
- const char * const names[])
+ 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(vp_dev->pci_dev, nvectors, nvectors,
- PCI_IRQ_MSIX);
+ 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;
@@ -308,13 +314,12 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
/* 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 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);
+ 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);
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index 217ca87..a6ad9ec 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -97,9 +97,8 @@ bool vp_notify(struct virtqueue *vq);
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[]);
+ struct virtqueue *vqs[], vq_callback_t *callbacks[],
+ const char * const names[], struct irq_affinity *desc);
const char *vp_bus_name(struct virtio_device *vdev);
/* Setup the affinity for a virtqueue:
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index e5ce310..a7a0981 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -384,13 +384,12 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
}
static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
- struct virtqueue *vqs[],
- vq_callback_t *callbacks[],
- const char * const names[])
+ 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);
struct virtqueue *vq;
- int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names);
+ int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, desc);
if (rc)
return rc;