[PATCH v3 07/13] KVM: selftests: x86: Fix the checks to XFD_ERR using and operation

From: Mingwei Zhang
Date: Tue Feb 21 2023 - 11:37:59 EST


Fix the checks to XFD_ERR using logical AND operation because XFD_ERR might
contain more information in the future. According Intel SDM Vol 1. 13.14:

"Specifically, the MSR is loaded with the logical AND of the IA32_XFD MSR
and the bitmap corresponding to the state component(s) required by the
faulting instruction."

So fix the check by using AND instead of '=='.

Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
tools/testing/selftests/kvm/x86_64/amx_test.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
index 296c954dfd6d..62fff3363b3b 100644
--- a/tools/testing/selftests/kvm/x86_64/amx_test.c
+++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
@@ -217,10 +217,10 @@ void guest_nm_handler(struct ex_regs *regs)
/* Check if #NM is triggered by XFEATURE_MASK_XTILEDATA */
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_ERR) & XFEATURE_MASK_XTILEDATA);
GUEST_ASSERT(rdmsr(MSR_IA32_XFD) & XFEATURE_MASK_XTILEDATA);
GUEST_SYNC(8);
- GUEST_ASSERT(rdmsr(MSR_IA32_XFD_ERR) == XFEATURE_MASK_XTILEDATA);
+ GUEST_ASSERT(rdmsr(MSR_IA32_XFD_ERR) & XFEATURE_MASK_XTILEDATA);
GUEST_ASSERT(rdmsr(MSR_IA32_XFD) & XFEATURE_MASK_XTILEDATA);
/* Clear xfd_err */
wrmsr(MSR_IA32_XFD_ERR, 0);
--
2.39.2.637.g21b0678d19-goog