diff --git a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c
index 91a8c4d0bd..31a56f02d0 100644
--- a/xen/arch/x86/acpi/power.c
+++ b/xen/arch/x86/acpi/power.c
@@ -288,6 +288,8 @@ static int enter_state(u32 state)
 
     microcode_update_one();
 
+    tsx_init(); /* Needs microcode.  May change HLE/RTM feature bits. */
+
     if ( !recheck_cpu_features(0) )
         panic("Missing previously available feature(s)\n");