Backmerge tag 'v6.9-rc5' into drm-next

Linux 6.9-rc5

I've had a persistent msm failure on clang, and the fix is in fixes
so just pull it back to fix that.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 045f666b4f12..8995730ce0bf 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2515,7 +2515,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 		vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
 
 		if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
-			vq_err(vq, "Guest moved used index from %u to %u",
+			vq_err(vq, "Guest moved avail index from %u to %u",
 				last_avail_idx, vq->avail_idx);
 			return -EFAULT;
 		}
@@ -2799,9 +2799,19 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 	r = vhost_get_avail_idx(vq, &avail_idx);
 	if (unlikely(r))
 		return false;
+
 	vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
+	if (vq->avail_idx != vq->last_avail_idx) {
+		/* Since we have updated avail_idx, the following
+		 * call to vhost_get_vq_desc() will read available
+		 * ring entries. Make sure that read happens after
+		 * the avail_idx read.
+		 */
+		smp_rmb();
+		return false;
+	}
 
-	return vq->avail_idx == vq->last_avail_idx;
+	return true;
 }
 EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
 
@@ -2838,9 +2848,19 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 		       &vq->avail->idx, r);
 		return false;
 	}
+
 	vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
+	if (vq->avail_idx != vq->last_avail_idx) {
+		/* Since we have updated avail_idx, the following
+		 * call to vhost_get_vq_desc() will read available
+		 * ring entries. Make sure that read happens after
+		 * the avail_idx read.
+		 */
+		smp_rmb();
+		return true;
+	}
 
-	return vq->avail_idx != vq->last_avail_idx;
+	return false;
 }
 EXPORT_SYMBOL_GPL(vhost_enable_notify);