[PATCH v3 03/11] vdpa: Add set_irq_affinity callback in vdpa_config_ops

[Xie Yongji]

This introduces set_irq_affinity callback in
vdpa_config_ops so that vdpa device driver can
get the interrupt affinity hint from the virtio
device driver. The interrupt affinity hint would
be needed by the interrupt affinity spreading
mechanism.

Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
---
 drivers/virtio/virtio_vdpa.c | 4 ++++
 include/linux/vdpa.h         | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index f72696b4c1c2..9eee8afabda8 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -282,9 +282,13 @@ static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
 	struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
 	struct vdpa_device *vdpa = vd_get_vdpa(vdev);
 	const struct vdpa_config_ops *ops = vdpa->config;
+	struct irq_affinity default_affd = { 0 };
 	struct vdpa_callback cb;
 	int i, err, queue_idx = 0;
 
+	if (ops->set_irq_affinity)
+		ops->set_irq_affinity(vdpa, desc ? desc : &default_affd);
+
 	for (i = 0; i < nvqs; ++i) {
 		if (!names[i]) {
 			vqs[i] = NULL;
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index d61f369f9cd6..10bd22387276 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -259,6 +259,13 @@ struct vdpa_map_file {
  *				@vdev: vdpa device
  *				@idx: virtqueue index
  *				Returns the irq affinity mask
+ * @set_irq_affinity:		Pass the irq affinity hint (best effort)
+ *				from the virtio device driver to vdpa
+ *				driver (optional).
+ *				Needed by the interrupt affinity spreading
+ *				mechanism.
+ *				@vdev: vdpa device
+ *				@desc: irq affinity hint
  * @set_group_asid:		Set address space identifier for a
  *				virtqueue group (optional)
  *				@vdev: vdpa device
@@ -353,6 +360,8 @@ struct vdpa_config_ops {
 			       const struct cpumask *cpu_mask);
 	const struct cpumask *(*get_vq_affinity)(struct vdpa_device *vdev,
 						 u16 idx);
+	void (*set_irq_affinity)(struct vdpa_device *vdev,
+				 struct irq_affinity *desc);
 
 	/* DMA ops */
 	int (*set_map)(struct vdpa_device *vdev, unsigned int asid,
-- 
2.20.1