Re: [PATCH v4 2/2] selftests/x86/amx: Update the ARCH_REQ_XCOMP_PERM test

On Sat, Jan 29 2022 at 09:36, Chang S. Bae wrote:

Update the arch_prctl test to check the permission bitmap whether the requested feature is added as expected or not.

Every non-dynamic feature that is enabled is permitted already for use. TILECFG is not dynamic feature. Ensure the bit is always on from ARCH_GET_XCOMP_PERM.

Running it on a machine which does not have AMX results in:

amx_64: [FAIL] xstate cpuid: invalid tile data size/offset: 0/0: Success

It's not a failure, really. Selftests are supposed to run on all machines and the proper thing to do if a hardware feature is not available is to SKIP the test and return 0.

Thanks,

tglx