On Thu, Dec 10 2020 at 14:01, Peter Zijlstra wrote: > On Thu, Dec 10, 2020 at 01:22:02PM +0100, Paolo Bonzini wrote: >> On 10/12/20 13:14, Peter Zijlstra wrote: >> > On Thu, Dec 10, 2020 at 12:42:36PM +0100, Paolo Bonzini wrote: >> > > On 07/12/20 18:41, Thomas Gleixner wrote: >> > > > Right this happens still occasionally, but for quite some time this is >> > > > 100% firmware sillyness and not a fundamental property of the hardware >> > > > anymore. >> > > >> > > It's still a fundamental property of old hardware. Last time I tried to >> > > kill support for processors earlier than Core 2, I had to revert it. That's >> > > older than Nehalem. >> > >> > Core2 doesn't use TSC for timekeeping anyway. KVM shouldn't either. >> >> On Core2, KVM guests pass TSC through kvmclock in order to get something >> usable and not incredibly slow. > > Which is incredibly wrong. Core2 is really not something which should prevent making all of this correct and robust. That'd be not only wrong, that'd be outright insane. Thanks, tglx