On Tue, Mar 25, 2025 at 08:18:11AM +0100, Jan Beulich wrote:
> In particular if we're running virtualized, the underlying hypervisor
> (which may be another Xen) may not surface MTRRs, and offer PAT only.
At least for Xen, I think we offer MTRR uniformly, even on PVH
guests?
> Fixes: 5a281883cdc3 ("Hardcode many cpu features for x86/64 -- we know
> 64-bit")
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
Acked-by: Roger Pau Monné <roger....@citrix.com>
My main concern is whether the !mtrr path is still functional. Have
you tried booting the resulting hypervisor with MTRR masked on CPUID?
(or alternatively short-circuiting cpu_has_mtrr == 0?)
Thanks, Roger.
