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Subject[PATCH 4.14 16/75] s390: vfio-ccw: Do not attempt to free no-op, test and tic cda.
4.14-stable review patch.  If anyone has any objections, please let me know.


From: "Jason J. Herne" <>

[ Upstream commit 408358b50deaf59b07c82a7bff8c7e7cce031fae ]

Because we do not make use of the cda (channel data address) for test,
no-op ccws no address translation takes place. This means cda could
contain a guest address which we do not want to attempt to free. Let's
check the command type and skip cda free when it is not needed.

For a TIC ccw, ccw->cda points to either a ccw in an existing chain or
it points to a whole new allocated chain. In either case the data will
be freed when the owning chain is freed.

Signed-off-by: Jason J. Herne <>
Reviewed-by: Dong Jia Shi <>
Reviewed-by: Pierre Morel <>
Message-Id: <>
Reviewed-by: Halil Pasic <>
Acked-by: Christian Borntraeger <>
Signed-off-by: Cornelia Huck <>
Signed-off-by: Sasha Levin <>
Signed-off-by: Greg Kroah-Hartman <>
drivers/s390/cio/vfio_ccw_cp.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -330,6 +330,8 @@ static void ccwchain_cda_free(struct ccw
struct ccw1 *ccw = chain->ch_ccw + idx;

+ if (ccw_is_test(ccw) || ccw_is_noop(ccw) || ccw_is_tic(ccw))
+ return;
if (!ccw->count)

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