Re: [PATCH v4 08/11] vdpa: Add eventfd for the vdpa callback

From: Jason Wang
Date: Tue Mar 28 2023 - 02:23:30 EST



在 2023/3/23 13:30, Xie Yongji 写道:
Add eventfd for the vdpa callback so that user
can signal it directly instead of triggering the
callback. It will be used for vhost-vdpa case.

Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>


Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

Thanks


---
drivers/vhost/vdpa.c | 2 ++
drivers/virtio/virtio_vdpa.c | 1 +
include/linux/vdpa.h | 6 ++++++
3 files changed, 9 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 7be9d9d8f01c..9cd878e25cff 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -599,9 +599,11 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
if (vq->call_ctx.ctx) {
cb.callback = vhost_vdpa_virtqueue_cb;
cb.private = vq;
+ cb.trigger = vq->call_ctx.ctx;
} else {
cb.callback = NULL;
cb.private = NULL;
+ cb.trigger = NULL;
}
ops->set_vq_cb(vdpa, idx, &cb);
vhost_vdpa_setup_vq_irq(v, idx);
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index f3826f42b704..2a095f37f26b 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -196,6 +196,7 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
/* Setup virtqueue callback */
cb.callback = callback ? virtio_vdpa_virtqueue_cb : NULL;
cb.private = info;
+ cb.trigger = NULL;
ops->set_vq_cb(vdpa, index, &cb);
ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index e52c9a37999c..0372b2e3d38a 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -13,10 +13,16 @@
* struct vdpa_calllback - vDPA callback definition.
* @callback: interrupt callback function
* @private: the data passed to the callback function
+ * @trigger: the eventfd for the callback (Optional).
+ * When it is set, the vDPA driver must guarantee that
+ * signaling it is functional equivalent to triggering
+ * the callback. Then vDPA parent can signal it directly
+ * instead of triggering the callback.
*/
struct vdpa_callback {
irqreturn_t (*callback)(void *data);
void *private;
+ struct eventfd_ctx *trigger;
};
/**