2024-03-14 11:44:51

by Muhammad Usama Anjum

[permalink] [raw]
Subject: [PATCH v2] selftests: x86: skip the tests if prerequisites aren't fulfilled

Skip instead of failing when prerequisite conditions aren't fulfilled,
such as invalid xstate values etc. This patch would make the tests show
as skip when run by:
make -C tools/testing/selftests/ TARGETS=x86 run_tests

...
# timeout set to 45
# selftests: x86: amx_64
# # xstate cpuid: invalid tile data size/offset: 0/0
ok 42 selftests: x86: amx_64 # SKIP
# timeout set to 45
# selftests: x86: lam_64
# # Unsupported LAM feature!
ok 43 selftests: x86: lam_64 # SKIP
...

Cc: Chang S. Bae <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Reviewed-by: Binbin Wu <[email protected]>
Signed-off-by: Muhammad Usama Anjum <[email protected]>
---
Changes since v1:
- Use arch_prctl to check if amx is supported
---
tools/testing/selftests/x86/amx.c | 27 ++++++++++-----------------
tools/testing/selftests/x86/lam.c | 2 +-
2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c
index d884fd69dd510..95aad6d8849be 100644
--- a/tools/testing/selftests/x86/amx.c
+++ b/tools/testing/selftests/x86/amx.c
@@ -103,21 +103,6 @@ static void clearhandler(int sig)

#define CPUID_LEAF1_ECX_XSAVE_MASK (1 << 26)
#define CPUID_LEAF1_ECX_OSXSAVE_MASK (1 << 27)
-static inline void check_cpuid_xsave(void)
-{
- uint32_t eax, ebx, ecx, edx;
-
- /*
- * CPUID.1:ECX.XSAVE[bit 26] enumerates general
- * support for the XSAVE feature set, including
- * XGETBV.
- */
- __cpuid_count(1, 0, eax, ebx, ecx, edx);
- if (!(ecx & CPUID_LEAF1_ECX_XSAVE_MASK))
- fatal_error("cpuid: no CPU xsave support");
- if (!(ecx & CPUID_LEAF1_ECX_OSXSAVE_MASK))
- fatal_error("cpuid: no OS xsave support");
-}

static uint32_t xbuf_size;

@@ -350,6 +335,7 @@ enum expected_result { FAIL_EXPECTED, SUCCESS_EXPECTED };

/* arch_prctl() and sigaltstack() test */

+#define ARCH_GET_XCOMP_SUPP 0x1021
#define ARCH_GET_XCOMP_PERM 0x1022
#define ARCH_REQ_XCOMP_PERM 0x1023

@@ -928,8 +914,15 @@ static void test_ptrace(void)

int main(void)
{
- /* Check hardware availability at first */
- check_cpuid_xsave();
+ unsigned long features;
+ long rc;
+
+ rc = syscall(SYS_arch_prctl, ARCH_GET_XCOMP_SUPP, &features);
+ if (rc || (features & XFEATURE_MASK_XTILE) != XFEATURE_MASK_XTILE) {
+ ksft_print_msg("no AMX support\n");
+ return KSFT_SKIP;
+ }
+
check_cpuid_xtiledata();

init_stashed_xsave();
diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c
index 215b8150b7cca..c0f016f45ee17 100644
--- a/tools/testing/selftests/x86/lam.c
+++ b/tools/testing/selftests/x86/lam.c
@@ -1183,7 +1183,7 @@ int main(int argc, char **argv)

if (!cpu_has_lam()) {
ksft_print_msg("Unsupported LAM feature!\n");
- return -1;
+ return KSFT_SKIP;
}

while ((c = getopt(argc, argv, "ht:")) != -1) {
--
2.39.2



2024-03-14 23:38:16

by Chang S. Bae

[permalink] [raw]
Subject: Re: [PATCH v2] selftests: x86: skip the tests if prerequisites aren't fulfilled

On 3/14/2024 4:44 AM, Muhammad Usama Anjum wrote:
> Skip instead of failing when prerequisite conditions aren't fulfilled,
> such as invalid xstate values etc. This patch would make the tests show
> as skip when run by:
> make -C tools/testing/selftests/ TARGETS=x86 run_tests
>
> ...
> # timeout set to 45
> # selftests: x86: amx_64
> # # xstate cpuid: invalid tile data size/offset: 0/0
> ok 42 selftests: x86: amx_64 # SKIP
> # timeout set to 45
> # selftests: x86: lam_64
> # # Unsupported LAM feature!
> ok 43 selftests: x86: lam_64 # SKIP
> ...
>
> Cc: Chang S. Bae <[email protected]>
> Acked-by: Kirill A. Shutemov <[email protected]>
> Reviewed-by: Binbin Wu <[email protected]>
> Signed-off-by: Muhammad Usama Anjum <[email protected]>
> ---
> Changes since v1:
> - Use arch_prctl to check if amx is supported
> ---
> tools/testing/selftests/x86/amx.c | 27 ++++++++++-----------------
> tools/testing/selftests/x86/lam.c | 2 +-
> 2 files changed, 11 insertions(+), 18 deletions(-)
>
> diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c
> index d884fd69dd510..95aad6d8849be 100644
> --- a/tools/testing/selftests/x86/amx.c
> +++ b/tools/testing/selftests/x86/amx.c
> @@ -103,21 +103,6 @@ static void clearhandler(int sig)
>
> #define CPUID_LEAF1_ECX_XSAVE_MASK (1 << 26)
> #define CPUID_LEAF1_ECX_OSXSAVE_MASK (1 << 27)
> -static inline void check_cpuid_xsave(void)
> -{
> - uint32_t eax, ebx, ecx, edx;
> -
> - /*
> - * CPUID.1:ECX.XSAVE[bit 26] enumerates general
> - * support for the XSAVE feature set, including
> - * XGETBV.
> - */
> - __cpuid_count(1, 0, eax, ebx, ecx, edx);
> - if (!(ecx & CPUID_LEAF1_ECX_XSAVE_MASK))
> - fatal_error("cpuid: no CPU xsave support");
> - if (!(ecx & CPUID_LEAF1_ECX_OSXSAVE_MASK))
> - fatal_error("cpuid: no OS xsave support");
> -}
>
> static uint32_t xbuf_size;
>
> @@ -350,6 +335,7 @@ enum expected_result { FAIL_EXPECTED, SUCCESS_EXPECTED };
>
> /* arch_prctl() and sigaltstack() test */
>
> +#define ARCH_GET_XCOMP_SUPP 0x1021
> #define ARCH_GET_XCOMP_PERM 0x1022
> #define ARCH_REQ_XCOMP_PERM 0x1023
>
> @@ -928,8 +914,15 @@ static void test_ptrace(void)
>
> int main(void)
> {
> - /* Check hardware availability at first */
> - check_cpuid_xsave();
> + unsigned long features;
> + long rc;
> +
> + rc = syscall(SYS_arch_prctl, ARCH_GET_XCOMP_SUPP, &features);
> + if (rc || (features & XFEATURE_MASK_XTILE) != XFEATURE_MASK_XTILE) {
> + ksft_print_msg("no AMX support\n");
> + return KSFT_SKIP;
> + }
> +

Reviewed-by: Chang S. Bae <[email protected]>

Thanks,
Chang

2024-03-26 20:51:52

by Shuah Khan

[permalink] [raw]
Subject: Re: [PATCH v2] selftests: x86: skip the tests if prerequisites aren't fulfilled

On 3/14/24 05:44, Muhammad Usama Anjum wrote:
> Skip instead of failing when prerequisite conditions aren't fulfilled,
> such as invalid xstate values etc. This patch would make the tests show
> as skip when run by:
> make -C tools/testing/selftests/ TARGETS=x86 run_tests
>
> ...
> # timeout set to 45
> # selftests: x86: amx_64
> # # xstate cpuid: invalid tile data size/offset: 0/0
> ok 42 selftests: x86: amx_64 # SKIP
> # timeout set to 45
> # selftests: x86: lam_64
> # # Unsupported LAM feature!
> ok 43 selftests: x86: lam_64 # SKIP
> ...
>
> Cc: Chang S. Bae <[email protected]>
> Acked-by: Kirill A. Shutemov <[email protected]>
> Reviewed-by: Binbin Wu <[email protected]>
> Signed-off-by: Muhammad Usama Anjum <[email protected]>
> ---
> Changes since v1:
> - Use arch_prctl to check if amx is supported

This should be mentioned in the changelog and also
show that there are bo backwards compatibility issues.

> ---
> tools/testing/selftests/x86/amx.c | 27 ++++++++++-----------------
> tools/testing/selftests/x86/lam.c | 2 +-
> 2 files changed, 11 insertions(+), 18 deletions(-)
>
> diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c
> index d884fd69dd510..95aad6d8849be 100644
> --- a/tools/testing/selftests/x86/amx.c
> +++ b/tools/testing/selftests/x86/amx.c
> @@ -103,21 +103,6 @@ static void clearhandler(int sig)
>
> #define CPUID_LEAF1_ECX_XSAVE_MASK (1 << 26)
> #define CPUID_LEAF1_ECX_OSXSAVE_MASK (1 << 27)
> -static inline void check_cpuid_xsave(void)
> -{
> - uint32_t eax, ebx, ecx, edx;
> -
> - /*
> - * CPUID.1:ECX.XSAVE[bit 26] enumerates general
> - * support for the XSAVE feature set, including
> - * XGETBV.
> - */
> - __cpuid_count(1, 0, eax, ebx, ecx, edx);
> - if (!(ecx & CPUID_LEAF1_ECX_XSAVE_MASK))
> - fatal_error("cpuid: no CPU xsave support");
> - if (!(ecx & CPUID_LEAF1_ECX_OSXSAVE_MASK))
> - fatal_error("cpuid: no OS xsave support");
> -}
>

Why doesn't the changelog mention the code removal?

thanks,
-- Shuah

2024-03-26 21:20:34

by Chang S. Bae

[permalink] [raw]
Subject: Re: [PATCH v2] selftests: x86: skip the tests if prerequisites aren't fulfilled

On 3/26/2024 1:51 PM, Shuah Khan wrote:
>
> show that there are bo backwards compatibility issues
In older kernels lacking AMX support [1], arch_prctl() returns EINVAL.
With AMX support, the kernel will properly set 'features'.

It is also worth noting that this simplification was previously
acknowledged [2], albeit some time ago.

Thanks,
Chang

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=db8268df0983adc2bb1fb48c9e5f7bfbb5f617f3
[2]
https://lore.kernel.org/lkml/[email protected]/



2024-03-27 16:18:46

by Shuah Khan

[permalink] [raw]
Subject: Re: [PATCH v2] selftests: x86: skip the tests if prerequisites aren't fulfilled

On 3/26/24 15:20, Chang S. Bae wrote:
> On 3/26/2024 1:51 PM, Shuah Khan wrote:
>>
>> show that there are bo backwards compatibility issues
> In older kernels lacking AMX support [1], arch_prctl() returns EINVAL. With AMX support, the kernel will properly set 'features'.
>
> It is also worth noting that this simplification was previously acknowledged [2], albeit some time ago.
>
> Thanks,
> Chang
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=db8268df0983adc2bb1fb48c9e5f7bfbb5f617f3
> [2] https://lore.kernel.org/lkml/[email protected]/
>
>

Thanks. This can be included in the change log so it is
clear.

thanks,
-- Shuah