[PATCH v12 17/19] x86/kvmclock: Abort SecureTSC enabled guest when kvmclock is selected

[Nikunj A Dadhania]

SecureTSC enabled guests should use TSC as the only clock source, abort
the guest when clock source switches to hypervisor controlled kvmclock.

Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
---
 arch/x86/kernel/kvmclock.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 5cd3717e103b..552c28cda874 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -22,6 +22,7 @@
 #include <asm/x86_init.h>
 #include <asm/kvmclock.h>
 #include <asm/timer.h>
+#include <asm/sev.h>
 
 static int kvmclock __initdata = 1;
 static int kvmclock_vsyscall __initdata = 1;
@@ -155,6 +156,13 @@ static void enable_kvm_sc_work(struct work_struct *work)
 {
 	u8 flags;
 
+	/*
+	 * For guest with SecureTSC enabled, TSC should be the only clock source.
+	 * Abort the guest when kvmclock is selected as the clock source.
+	 */
+	if (cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
+		snp_abort();
+
 	old_pv_sched_clock = static_call_query(pv_sched_clock);
 	flags = pvclock_read_flags(&hv_clock_boot[0].pvti);
 	kvm_sched_clock_init(flags & PVCLOCK_TSC_STABLE_BIT);
-- 
2.34.1