Re: [kvm-unit-tests PATCH] s390x: Use the right constraints in intercept.c

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Tue,  4 Apr 2023 12:24:37 +0200
Thomas Huth <thuth@redhat.com> wrote:

> stpx, spx, stap and stidp use addressing via "base register", i.e.
> if register 0 is used, the base address will be 0, independent from
> the value of the register. Thus we must not use the "r" constraint
> here to avoid register 0. This fixes test failures when compiling
> with Clang instead of GCC, since Clang apparently prefers to use
> register 0 in some cases where GCC never uses register 0.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

maybe you can also add a couple of Fixes tags:

Fixes: 2667b05e ("s390x: Interception tests")
Fixes: 484a3a57 ("s390x: add stidp interception test")

in any case:

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

> ---
>  s390x/intercept.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/s390x/intercept.c b/s390x/intercept.c
> index 9e826b6c..faa74bbb 100644
> --- a/s390x/intercept.c
> +++ b/s390x/intercept.c
> @@ -36,16 +36,16 @@ static void test_stpx(void)
>  
>  	expect_pgm_int();
>  	low_prot_enable();
> -	asm volatile(" stpx 0(%0) " : : "r"(8));
> +	asm volatile(" stpx 0(%0) " : : "a"(8));
>  	low_prot_disable();
>  	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
>  
>  	expect_pgm_int();
> -	asm volatile(" stpx 0(%0) " : : "r"(1));
> +	asm volatile(" stpx 0(%0) " : : "a"(1));
>  	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
>  
>  	expect_pgm_int();
> -	asm volatile(" stpx 0(%0) " : : "r"(-8L));
> +	asm volatile(" stpx 0(%0) " : : "a"(-8L));
>  	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
>  }
>  
> @@ -70,13 +70,13 @@ static void test_spx(void)
>  
>  	report_prefix_push("operand not word aligned");
>  	expect_pgm_int();
> -	asm volatile(" spx 0(%0) " : : "r"(1));
> +	asm volatile(" spx 0(%0) " : : "a"(1));
>  	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
>  	report_prefix_pop();
>  
>  	report_prefix_push("operand outside memory");
>  	expect_pgm_int();
> -	asm volatile(" spx 0(%0) " : : "r"(-8L));
> +	asm volatile(" spx 0(%0) " : : "a"(-8L));
>  	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
>  	report_prefix_pop();
>  
> @@ -113,16 +113,16 @@ static void test_stap(void)
>  
>  	expect_pgm_int();
>  	low_prot_enable();
> -	asm volatile ("stap 0(%0)\n" : : "r"(8));
> +	asm volatile ("stap 0(%0)\n" : : "a"(8));
>  	low_prot_disable();
>  	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
>  
>  	expect_pgm_int();
> -	asm volatile ("stap 0(%0)\n" : : "r"(1));
> +	asm volatile ("stap 0(%0)\n" : : "a"(1));
>  	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
>  
>  	expect_pgm_int();
> -	asm volatile ("stap 0(%0)\n" : : "r"(-8L));
> +	asm volatile ("stap 0(%0)\n" : : "a"(-8L));
>  	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
>  }
>  
> @@ -138,16 +138,16 @@ static void test_stidp(void)
>  
>  	expect_pgm_int();
>  	low_prot_enable();
> -	asm volatile ("stidp 0(%0)\n" : : "r"(8));
> +	asm volatile ("stidp 0(%0)\n" : : "a"(8));
>  	low_prot_disable();
>  	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
>  
>  	expect_pgm_int();
> -	asm volatile ("stidp 0(%0)\n" : : "r"(1));
> +	asm volatile ("stidp 0(%0)\n" : : "a"(1));
>  	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
>  
>  	expect_pgm_int();
> -	asm volatile ("stidp 0(%0)\n" : : "r"(-8L));
> +	asm volatile ("stidp 0(%0)\n" : : "a"(-8L));
>  	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
>  }
>