[PATCH v6 13/16] x86/kvmclock: Skip kvmclock when Secure TSC is available

From: Nikunj A Dadhania
Date: Tue Nov 28 2023 - 08:02:56 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>
---
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 fb8f52149be9..e3de354abf74 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -288,7 +288,7 @@ 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