From 890d33561337ffeba0d8ba42517e71288cfee2b6 Mon Sep 17 00:00:00 2001
From: Vincent Whitchurch <vincent.whitchurch@axis.com>
Date: Tue, 26 Oct 2021 15:31:00 +0200
Subject: [PATCH] virtio-ring: fix DMA metadata flags
Git-commit: 890d33561337ffeba0d8ba42517e71288cfee2b6
Patch-mainline: v5.15
References: git-fixes stable-5.14.16
The flags are currently overwritten, leading to the wrong direction
being passed to the DMA unmap functions.
Fixes: 72b5e8958738aaa4 ("virtio-ring: store DMA metadata in desc_extra for split virtqueue")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20211026133100.17541-1-vincent.whitchurch@axis.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/virtio/virtio_ring.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index dd95dfd85e98..3035bb6f5458 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -576,7 +576,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
/* Last one doesn't continue. */
desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
if (!indirect && vq->use_dma_api)
- vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags =
+ vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &=
~VRING_DESC_F_NEXT;
if (indirect) {
--
2.26.2