fixes for 4.19

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.19/series b/queue-4.19/series
index 78bdfd41792013d8891126b8043d23bafbd6277e..66323fc634df23bc8cc5e907ba3a13f0b42f29ef 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -288,3 +288,4 @@ media-uvcvideo-fix-error-path-in-control-parsing-failure.patch
 media-b2c2-flexcop-usb-add-sanity-checking.patch
 media-cxusb-detect-cxusb_ctrl_msg-error-in-query.patch
 media-imon-invalid-dereference-in-imon_touch_event.patch
+virtio_ring-fix-return-code-on-dma-mapping-fails.patch

diff --git a/queue-4.19/virtio_ring-fix-return-code-on-dma-mapping-fails.patch b/queue-4.19/virtio_ring-fix-return-code-on-dma-mapping-fails.patch
new file mode 100644 (file)
index 0000000..6f0d871
--- /dev/null
+++ b/queue-4.19/virtio_ring-fix-return-code-on-dma-mapping-fails.patch
@@ -0,0 +1,48 @@
+From e1840d10625ea93cf540101ddad94a97348480dd Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Thu, 14 Nov 2019 13:46:46 +0100
+Subject: virtio_ring: fix return code on DMA mapping fails
+
+From: Halil Pasic <pasic@linux.ibm.com>
+
+[ Upstream commit f7728002c1c7bfa787b276a31c3ef458739b8e7c ]
+
+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: Sasha Levin <sashal@kernel.org>
+---
+ 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 9529e28e18222..6228b48d1e127 100644
+--- a/drivers/virtio/virtio_ring.c
++++ b/drivers/virtio/virtio_ring.c
+@@ -431,7 +431,7 @@ unmap_release:
+               kfree(desc);
+ 
+       END_USE(vq);
+-      return -EIO;
++      return -ENOMEM;
+ }
+ 
+ /**
+-- 
+2.20.1
+