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>
This commit is contained in:
Christoph Hellwig 2017-02-05 18:15:22 +01:00 committed by Michael S. Tsirkin
parent 52a6151612
commit fb5e31d970
20 changed files with 48 additions and 34 deletions

View file

@ -7,6 +7,8 @@
#include <linux/virtio_byteorder.h>
#include <uapi/linux/virtio_config.h>
struct irq_affinity;
/**
* virtio_config_ops - operations for configuring a virtio device
* @get: read the value of a configuration field
@ -68,9 +70,8 @@ struct virtio_config_ops {
void (*set_status)(struct virtio_device *vdev, u8 status);
void (*reset)(struct virtio_device *vdev);
int (*find_vqs)(struct virtio_device *, 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);
void (*del_vqs)(struct virtio_device *);
u64 (*get_features)(struct virtio_device *vdev);
int (*finalize_features)(struct virtio_device *vdev);
@ -169,7 +170,7 @@ struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
vq_callback_t *callbacks[] = { c };
const char *names[] = { n };
struct virtqueue *vq;
int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names, NULL);
if (err < 0)
return ERR_PTR(err);
return vq;