Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.3 25/95] virtio_ring: fix return code on DMA mapping fails | Date | Wed, 27 Nov 2019 21:31:42 +0100 |
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From: Halil Pasic <pasic@linux.ibm.com>
commit f7728002c1c7bfa787b276a31c3ef458739b8e7c upstream.
Commit 780bc7903a32 ("virtio_ring: Support DMA APIs") makes virtqueue_add() return -EIO when we fail to map our I/O buffers. This is a very realistic scenario for guests with encrypted memory, as swiotlb may run out of space, depending on it's size and the I/O load.
The virtio-blk driver interprets -EIO form virtqueue_add() as an IO error, despite the fact that swiotlb full is in absence of bugs a recoverable condition.
Let us change the return code to -ENOMEM, and make the block layer recover form these failures when virtio-blk encounters the condition described above.
Cc: stable@vger.kernel.org Fixes: 780bc7903a32 ("virtio_ring: Support DMA APIs") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/virtio/virtio_ring.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -583,7 +583,7 @@ unmap_release: kfree(desc); END_USE(vq); - return -EIO; + return -ENOMEM; } static bool virtqueue_kick_prepare_split(struct virtqueue *_vq) @@ -1085,7 +1085,7 @@ unmap_release: kfree(desc); END_USE(vq); - return -EIO; + return -ENOMEM; } static inline int virtqueue_add_packed(struct virtqueue *_vq,
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