On Wed, Jun 09, 2021 at 02:14:39PM -0700, Pawan Gupta wrote: > On CPUs that deprecated TSX, clearing the enumeration bits CPUID.RTM and > CPUID.HLE may not be desirable in some corner cases. Like a saved guest > would refuse to resume if it was saved before the microcode update > that deprecated TSX. Why is a global option necessary to allow those guests to be resumed? Why can't KVM_GET_SUPPORTED_CPUID always return the HLE and RTM bits as supported when the host CPU has them? > > Add a cmdline option "tsx=fake" to not clear CPUID bits even when the > hardware always aborts TSX transactions. > > Suggested-by: Tony Luck <tony.luck@xxxxxxxxx> > Suggested-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> > Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx> > Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> > Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> > Tested-by: Neelima Krishnan <neelima.krishnan@xxxxxxxxx> [...] -- Eduardo
