On Mon, Jun 24, 2019 at 09:46:17AM -0700, Andi Kleen wrote: > > > The other hypervisors are relatively obscure, but eventually > > > someone will hit problems. > > > > any idea if there's any other flag/way we could use to detect those? > > I'm not aware of a generic way to detect any hypervisor unfortunately. > > There are hypervisor reserved cpuid ranges, in theory you could > probe the existence of those. But there might be always some which > don't have extra CPUIDs. > > > > > adding few virtualization folks to the loop > > and attaching the original patch > > > > thanks, > > jirka > > > > > > --- > > Tom Vaden reported false failure of check_msr function, because > > some servers can do POST tracing and enable LBR tracing during > > the boot. > > Just to understand the original problem, the LBR registers > get locked somehow? It would be reasonable to not use LBRs > in this case. We just need to make sure everything > else is still probed.
Tom, plz correctme if I'm wrongm but AFAIK because the LBR tracing is enabled during the boot the lbr_from/lbr_to registers will fail the check_msr 'val_new != val_tmp' check if there's no good way to detect this, maybe we add boot option to disable the check_msr check jirka
