When a CPU does not have AMX, the test fails. But this is wrong as it should be runnable regardless. Skip the test instead.
Also, simplify the feature check using arch_prctl() instead of CPUID. The syscall is more trustworthy as the kernel controls the feature permission.
Reported-by: Thomas Gleixner tglx@linutronix.de Fixes: 6a3e0651b4a ("selftests/x86/amx: Add test cases for AMX state management") Signed-off-by: Chang S. Bae chang.seok.bae@intel.com Cc: Shuah Khan shuah@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- Changes from v2: None
Changes from v1: * Simplify the feature check code (Shuah Khan). --- tools/testing/selftests/x86/amx.c | 31 ++++++++++--------------------- 1 file changed, 10 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c index d884fd69dd51..f0b1efe89ef7 100644 --- a/tools/testing/selftests/x86/amx.c +++ b/tools/testing/selftests/x86/amx.c @@ -101,24 +101,6 @@ static void clearhandler(int sig) #define XFEATURE_MASK_XTILEDATA (1 << XFEATURE_XTILEDATA) #define XFEATURE_MASK_XTILE (XFEATURE_MASK_XTILECFG | XFEATURE_MASK_XTILEDATA)
-#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;
static struct { @@ -350,6 +332,7 @@ 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
@@ -928,10 +911,16 @@ static void test_ptrace(void)
int main(void) { - /* Check hardware availability at first */ - check_cpuid_xsave(); - check_cpuid_xtiledata(); + unsigned long features; + long rc;
+ rc = syscall(SYS_arch_prctl, ARCH_GET_XCOMP_SUPP, &features); + if (rc || (features & XFEATURE_MASK_XTILE) != XFEATURE_MASK_XTILE) { + printf("[SKIP]\tno AMX support.\n"); + exit(KSFT_FAIL); + } + + check_cpuid_xtiledata(); init_stashed_xsave(); sethandler(SIGILL, handle_noperm, 0);