On Mon, Dec 14, 2015 at 11:37:16PM +0100, Borislav Petkov wrote: > On Mon, Dec 14, 2015 at 02:11:46PM -0500, Raj, Ashok wrote: > > This is mostly harmless.. since the MCG_CAP space is shared and has no > > conflict between vendors. Also just the CAP being set has no effect. > > Of course it does - we check SER_P in machine_check_poll() and when > I emulate an AMD guest and inject errors into it, error handling is > obviously wrong, see: > > https://lkml.kernel.org/r/20151123150355.GE5134@pd.tnic > I can see how this hurts.. since the poller isn't doing cpu model specific stuff..? in the LMCE case, even if you advertise MCG_LMCE_P in MCG_CAP, the guest kernel wont call intel_init_lmce() only from mce_intel.c.. so the same problem won't happen. but the issue Eduardo mentioned seems like the following. New QEMU_LMCE + New KVM_LMCE + New_GUEST_LMCE - No problem but if you were to migrage the Guest_LMCE to a non-LMCE supported KVM host we could run into an issue.. is this the compatibility issue that you were looking to fix Eduardo?