From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Make kvm_synchronize_all_tsc() nop for TD-guest.
TDX module specification, 9.11.1 TSC Virtualization
"Virtual TSC values are consistent among all the TD;s VCPUs at the
level suppored by the CPU".
There is no need for qemu to synchronize tsc and VMM can't access
to guest TSC. Actually do_kvm_synchronize_tsc() hits assert due to
failure to write to guest tsc.
> qemu/target/i386/kvm.c:235: kvm_get_tsc: Assertion `ret == 1' failed.
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
target/i386/kvm/kvm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index c29cb420a1..ecb1714920 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -254,7 +254,7 @@ void kvm_synchronize_all_tsc(void)
{
CPUState *cpu;
- if (kvm_enabled()) {
+ if (kvm_enabled() && vm_type != KVM_X86_TDX_VM) {
CPU_FOREACH(cpu) {
run_on_cpu(cpu, do_kvm_synchronize_tsc, RUN_ON_CPU_NULL);
}
--
2.25.1
