On Mon, Mar 08, 2021 at 12:41:26PM +0000, Andrew Cooper wrote: > On 05/03/2021 09:50, Jan Beulich wrote: > > Linux has been warning ("firmware bug") about this bit being clear for a > > long time. While writable in older hardware it has been readonly on more > > than just most recent hardware. For simplicitly report it always set (if > > anything we may want to log the issue ourselves if it turns out to be > > clear on older hardware). > > > > Signed-off-by: Jan Beulich <jbeul...@suse.com> > > I realise Linux is complaining, but simply setting the bit isn't a fix. > > This needs corresponding updates in the ACPI tables, as well as Pstate > MSRs, or Linux will derive a false relationship between the TSC rate and > wallclock.
Is there any description of those relations? I don't seem to find any other MSR referencing the TscFreqSel bit in HWCR on the AMD Open-Source Register Reference, but I might be looking at the wrong place. Thanks, Roger.