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authorDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>2017-10-11 05:38:21 +0300
committerCornelia Huck <cohuck@redhat.com>2017-10-16 12:10:13 +0300
commit688c29533ffc969773bc860d07d3a5f1995f5878 (patch)
tree1ec90512baba9a1fbe72d0b3f86918af7cb6d53c /drivers/s390
parentfe3af62553896d2a6b13c931137406681d76c3e4 (diff)
downloadlinux-688c29533ffc969773bc860d07d3a5f1995f5878.tar.xz
vfio: ccw: bypass bad idaw address when fetching IDAL ccws
We currently return the same error code (-EFAULT) to indicate two different error cases: 1. a bug in vfio-ccw implementation has been found. 2. a buggy channel program has been detected. This brings difficulty for userland program (specifically Qemu) to handle. Let's use -EFAULT to only indicate the first case. For the second case, we simply hand over the ccws to lower level for further handling. Notice: Once a bad idaw address is detected, the current behavior is to suppress the ssch. With this fix, the channel program will be accepted, and part of the channel program (the part ahead of the bad idaw) could possibly be executed by the device before I/O conclusion. Suggested-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Message-Id: <20171011023822.42948-2-bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/vfio_ccw_cp.c4
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 5ccfdc80d0ec..722f8b8c7273 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -569,10 +569,6 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
for (i = 0; i < idaw_nr; i++) {
idaw_iova = *(idaws + i);
- if (IS_ERR_VALUE(idaw_iova)) {
- ret = -EFAULT;
- goto out_free_idaws;
- }
ret = pfn_array_alloc_pin(pat->pat_pa + i, cp->mdev,
idaw_iova, 1);