Re: [kvm-unit-tests PATCH 2/8] s390x: diag308: Only test subcode 2 under QEMU

[Thomas Huth <thuth@redhat.com>]

On 05/04/2022 09.52, Janosch Frank wrote:
> Other hypervisors might implement it and therefore not send a
> specification exception.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>   s390x/diag308.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/s390x/diag308.c b/s390x/diag308.c
> index c9d6c499..9614f9a9 100644
> --- a/s390x/diag308.c
> +++ b/s390x/diag308.c
> @@ -8,6 +8,7 @@
>   #include <libcflat.h>
>   #include <asm/asm-offsets.h>
>   #include <asm/interrupt.h>
> +#include <hardware.h>
>   
>   /* The diagnose calls should be blocked in problem state */
>   static void test_priv(void)
> @@ -75,7 +76,7 @@ static void test_subcode6(void)
>   /* Unsupported subcodes should generate a specification exception */
>   static void test_unsupported_subcode(void)
>   {
> -	int subcodes[] = { 2, 0x101, 0xffff, 0x10001, -1 };
> +	int subcodes[] = { 0x101, 0xffff, 0x10001, -1 };
>   	int idx;
>   
>   	for (idx = 0; idx < ARRAY_SIZE(subcodes); idx++) {
> @@ -85,6 +86,18 @@ static void test_unsupported_subcode(void)
>   		check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
>   		report_prefix_pop();
>   	}
> +
> +	/*
> +	 * Subcode 2 is not available under QEMU but might be on other
> +	 * hypervisors.
> +	 */
> +	if (detect_host() != HOST_IS_TCG && detect_host() != HOST_IS_KVM) {

Shouldn't this be rather the other way round instead?

	if (detect_host() == HOST_IS_TCG || detect_host() == HOST_IS_KVM)

?

... anyway, since you already used a similar if-clause in your first patch, 
it might make sense to add a helper function a la host_is_qemu() to check 
whether we're running on QEMU or not.

> +		report_prefix_pushf("0x%04x", 2);

	report_prefix_pushf("0x02") ?

> +		expect_pgm_int();
> +		asm volatile ("diag %0,%1,0x308" :: "d"(0), "d"(2));
> +		check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
> +		report_prefix_pop();
> +	}
>   }

  Thomas