Re: [PATCH v1] s390x/ioinst: Fix wrong MSCH alignment check on little endian

[Thomas Huth <thuth@redhat.com>]

On 05/08/2021 16.37, David Hildenbrand wrote:
> schib->pmcw.chars is 32bit, not 16bit. This fixes the kvm-unit-tests
> "css" test, which fails with:
> 
>    FAIL: Channel Subsystem: measurement block format1: Unaligned MB origin:
>    Program interrupt: expected(21) == received(0)
> 
> Because we end up not injecting an operand program exception.
> 
> Fixes: a54b8ac340c2 ("css: SCHIB measurement block origin must be aligned")
> Cc: Halil Pasic <pasic@linux.ibm.com>
> Cc: Cornelia Huck <cohuck@redhat.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Cc: Thomas Huth <thuth@redhat.com>
> Cc: Pierre Morel <pmorel@linux.ibm.com>
> Cc: qemu-s390x@nongnu.org
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>   target/s390x/ioinst.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index 4eb0a7a9f8..bdae5090bc 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -123,7 +123,7 @@ static int ioinst_schib_valid(SCHIB *schib)
>       }
>       /* for MB format 1 bits 26-31 of word 11 must be 0 */
>       /* MBA uses words 10 and 11, it means align on 2**6 */
> -    if ((be16_to_cpu(schib->pmcw.chars) & PMCW_CHARS_MASK_MBFC) &&
> +    if ((be32_to_cpu(schib->pmcw.chars) & PMCW_CHARS_MASK_MBFC) &&
>           (be64_to_cpu(schib->mba) & 0x03fUL)) {
>           return 0;
>       }
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>