Re: [Qemu-devel] [PATCH] s390-ccw: Fix alignment for CCW1

[Farhan Ali]

On 08/25/2017 10:04 AM, Cornelia Huck wrote:
On Fri, 25 Aug 2017 09:24:46 -0400
Farhan Ali <al...@linux.vnet.ibm.com> wrote:

The commit 198c0d1f9df8c4 s390x/css: check ccw address validity
exposes an alignment issue in ccw bios.

According to PoP the CCW must be doubleword aligned. Let's fix
this in the bios.

Cc: qemu-sta...@nongnu.org
Signed-off-by: Farhan Ali <al...@linux.vnet.ibm.com>
Reviewed-by: Halil Pasic <pa...@linux.vnet.ibm.com>
Reviewed-by: Eric Farman <far...@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntrae...@de.ibm.com>
---
 pc-bios/s390-ccw/cio.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pc-bios/s390-ccw/cio.h b/pc-bios/s390-ccw/cio.h
index f5b4549..55eaeee 100644
--- a/pc-bios/s390-ccw/cio.h
+++ b/pc-bios/s390-ccw/cio.h
@@ -133,7 +133,7 @@ struct ccw1 {
     __u8 flags;
     __u16 count;
     __u32 cda;
-} __attribute__ ((packed));
+} __attribute__ ((packed, aligned(8)));

 #define CCW_FLAG_DC              0x80
 #define CCW_FLAG_CC              0x40

Currently testing.

This looks obviously right, but did you figure out what the (probably
unrelated) other failure was?


That is still under investigation, for some reason it only fails for an 
LDL DASD and it works for SCSIs and CDL DASD.