On Tue, Feb 21, 2023, Mingwei Zhang wrote: > Add an extra check to IA32_XFD to ensure the behavior is consistent with > the AMX archtecture. In addition, repeat the checks across context switch > to ensure the values of IA32_XFD and IA32_XFD_ERR are well preserved. > > Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx> > --- > tools/testing/selftests/kvm/x86_64/amx_test.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c > index ac49b14460b6..296c954dfd6d 100644 > --- a/tools/testing/selftests/kvm/x86_64/amx_test.c > +++ b/tools/testing/selftests/kvm/x86_64/amx_test.c > @@ -218,8 +218,10 @@ void guest_nm_handler(struct ex_regs *regs) > GUEST_SYNC(7); > GUEST_ASSERT((get_cr0() & X86_CR0_TS) == 0); > GUEST_ASSERT(rdmsr(MSR_IA32_XFD_ERR) == XFEATURE_MASK_XTILEDATA); > + GUEST_ASSERT(rdmsr(MSR_IA32_XFD) & XFEATURE_MASK_XTILEDATA); These should use ==, not &. The test explicitly writes MSR_IA32_XFD, i.e. if there are extra bits set then something is buggy.