Re: [kvm-unit-tests PATCH v1] s390x/skey: Test for ADDRESSING exceptions

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

On Fri,  3 Sep 2021 18:25:37 +0200
David Hildenbrand <david@redhat.com> wrote:

> ... used to be broken in TCG, so let's add a very simple test for SSKE
> and ISKE. In order to test RRBE as well, introduce a helper to call the
> machine instruction.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Maybe consider testing rrbm too, but anyway:

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

> ---
>  lib/s390x/asm/mem.h | 12 ++++++++++++
>  s390x/skey.c        | 28 ++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/lib/s390x/asm/mem.h b/lib/s390x/asm/mem.h
> index 40b22b6..845c00c 100644
> --- a/lib/s390x/asm/mem.h
> +++ b/lib/s390x/asm/mem.h
> @@ -50,6 +50,18 @@ static inline unsigned char get_storage_key(void *addr)
>  	return skey;
>  }
>  
> +static inline unsigned char reset_reference_bit(void *addr)
> +{
> +	int cc;
> +
> +	asm volatile(
> +		"rrbe	0,%1\n"
> +		"ipm	%0\n"
> +		"srl	%0,28\n"
> +		: "=d" (cc) : "a" (addr) : "cc");
> +	return cc;
> +}
> +
>  #define PFMF_FSC_4K 0
>  #define PFMF_FSC_1M 1
>  #define PFMF_FSC_2G 2
> diff --git a/s390x/skey.c b/s390x/skey.c
> index 2539944..58a5543 100644
> --- a/s390x/skey.c
> +++ b/s390x/skey.c
> @@ -120,6 +120,33 @@ static void test_priv(void)
>  	report_prefix_pop();
>  }
>  
> +static void test_invalid_address(void)
> +{
> +	void *inv_addr = (void *)-1ull;
> +
> +	report_prefix_push("invalid address");
> +
> +	report_prefix_push("sske");
> +	expect_pgm_int();
> +	set_storage_key(inv_addr, 0, 0);
> +	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
> +	report_prefix_pop();
> +
> +	report_prefix_push("iske");
> +	expect_pgm_int();
> +	get_storage_key(inv_addr);
> +	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
> +	report_prefix_pop();
> +
> +	report_prefix_push("rrbe");
> +	expect_pgm_int();
> +	reset_reference_bit(inv_addr);
> +	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
> +	report_prefix_pop();
> +
> +	report_prefix_pop();
> +}
> +
>  int main(void)
>  {
>  	report_prefix_push("skey");
> @@ -128,6 +155,7 @@ int main(void)
>  		goto done;
>  	}
>  	test_priv();
> +	test_invalid_address();
>  	test_set();
>  	test_set_mb();
>  	test_chg();