AMD does not support APIC TSC-deadline timer mode. AVIC hardware
will generate GP fault when guest kernel writes 1 to bits [18]
of the APIC LVTT register (offset 0x32) to set the timer mode.
(Note: bit 18 is reserved on AMD system).
Therefore, always intercept and let KVM emulate the MSR accesses.
Fixes: f3d7c8aa6882 ("KVM: SVM: Fix x2APIC MSRs interception")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
arch/x86/kvm/svm/svm.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index aef63aae922d..3e0639a68385 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -118,7 +118,14 @@ static const struct svm_direct_access_msrs {
{ .index = X2APIC_MSR(APIC_ESR), .always = false },
{ .index = X2APIC_MSR(APIC_ICR), .always = false },
{ .index = X2APIC_MSR(APIC_ICR2), .always = false },
- { .index = X2APIC_MSR(APIC_LVTT), .always = false },
+
+ /*
+ * Note:
+ * AMD does not virtualize APIC TSC-deadline timer mode, but it is
+ * emulated by KVM. When setting APIC LVTT (0x832) register bit 18,
+ * the AVIC hardware would generate GP fault. Therefore, always
+ * intercept the MSR 0x832, and do not setup direct_access_msr.
+ */
{ .index = X2APIC_MSR(APIC_LVTTHMR), .always = false },
{ .index = X2APIC_MSR(APIC_LVTPC), .always = false },
{ .index = X2APIC_MSR(APIC_LVT0), .always = false },
--
2.34.1
