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

[Halil Pasic]

On Thu,  5 Aug 2021 16:37:53 +0200
David Hildenbrand <david@redhat.com> 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>

Reviewed-by: Halil Pasic <pasic@linux.ibm.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;
>      }