On Tue, Jul 14, 2020 at 02:09:05PM +0200, Joerg Roedel wrote: > @@ -1028,6 +1036,16 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication) > struct ghcb *ghcb; > > lockdep_assert_irqs_disabled(); > + > + /* > + * #DB is special and needs to be handled outside of the intrumentation_begin()/end(). > + * Otherwise the #VC handler could be raised recursivly. > + */ > + if (error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB) { > + vc_handle_trap_db(regs); > + return; > + } > + > instrumentation_begin(); Wait what?! That makes no sense what so ever.