Patch "vdpa: Add eventfd for the vdpa callback" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    vdpa: Add eventfd for the vdpa callback

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vdpa-add-eventfd-for-the-vdpa-callback.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 00dbbdb69a69487fbe838e2e7c457181e2e29e1b
Author: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
Date:   Thu Mar 23 13:30:40 2023 +0800

    vdpa: Add eventfd for the vdpa callback
    
    [ Upstream commit 5e68470f4e80a4120e9ecec408f6ab4ad386bd4a ]
    
    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>
    Message-Id: <20230323053043.35-9-xieyongji@xxxxxxxxxxxxx>
    Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
    Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
    Stable-dep-of: 02e9e9366fef ("vhost_vdpa: assign irq bypass producer token correctly")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index c9f585db1553c..fdd175730d327 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -422,9 +422,11 @@ 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 3f95dedcccebe..7b2c37a3880f8 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -180,6 +180,7 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
 	/* Setup virtqueue callback */
 	cb.callback = virtio_vdpa_virtqueue_cb;
 	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 30bc7a7223bb7..2ee60c7c1eb04 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -11,10 +11,16 @@
  * 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;
 };
 
 /**