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

[Farhan Ali <alifm@linux.vnet.ibm.com>]

On 08/25/2017 10:04 AM, Cornelia Huck wrote:
> On Fri, 25 Aug 2017 09:24:46 -0400
> Farhan Ali <alifm@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-stable@nongnu.org
>> Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
>> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
>> Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
>> Acked-by: Christian Borntraeger <borntraeger@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.