On Fri, 2026-05-15 at 12:19 -0700, Sean Christopherson wrote: > Add a "tsc_properties" set of flags and use it to annotate whether the > TSC operates at a known and/or reliable frequency when registering a > paravirtual TSC calibration routine. Currently, each PV flow manually > sets the associated feature flags, but often in haphazard fashion that > makes it difficult for unfamiliar readers to see the properties of the > TSC when running under a particular hypervisor. > > The other, bigger issue with manually setting the feature flags is that > it decouples the flags from the calibration routine. E.g. in theory, PV > code could mark the TSC as having a known frequency, but then have its > PV calibration discarded in favor of a method that doesn't use that known > frequency. Passing the TSC properties along with the calibration routine > will allow adding sanity checks to guard against replacing a "better" > calibration routine with a "worse" routine. > > As a bonus, the flags also give developers working on new PV code a heads > up that they should at least mark the TSC as having a known frequency. > > Reviewed-by: Michael Kelley <[email protected]> > Tested-by: Michael Kelley <[email protected]> > Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: David Woodhouse <[email protected]>
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