[PATCH v8 13/16] x86/kvmclock: Skip kvmclock when Secure TSC is available

From: Nikunj A Dadhania
Date: Thu Feb 15 2024 - 07:09:03 EST


For AMD SNP guests having Secure TSC enabled, skip using the kvmclock.
The guest kernel will fallback and use Secure TSC based clocksource.

Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
Tested-by: Peter Gonda <pgonda@xxxxxxxxxx>
---
arch/x86/kernel/kvmclock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 5bb395551c44..855ef65dbc4a 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -289,7 +289,7 @@ void __init kvmclock_init(void)
{
u8 flags;

- if (!kvm_para_available() || !kvmclock)
+ if (!kvm_para_available() || !kvmclock || cpu_feature_enabled(X86_FEATURE_SNP_SECURE_TSC))
return;

if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) {
--
2.34.1