Re: runtime regression with "x86/mm/pat: Emulate PAT when it is disabled"

[Borislav Petkov]

On Thu, Mar 10, 2016 at 09:49:51AM -0700, Toshi Kani wrote:
> This confirms the issue - QEMU's virtual Intel CPU does not support MTRR.Â
> 
> When MTRR is disabled, the kernel does not call pat_init(). Âpat_enabled()
> is still set to true whenÂCONFIG_X86_PAT is set. ÂCONFIG_X86_PAT depends on
> CONFIG_MTRR, and assumes that MTRR is enabled.Â

Aha, so "qemu32" model doesn't support MTRRs but "kvm32" does, for
example. And so do the majority of the other CPU types.

Paul, can you guys run with something else besides "qemu32"? You can
even take a 64-bit one and run a 32-bit guest on it.

:-)

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix ImendÃrffer, Jane Smithard, Graham Norton, HRB 21284 (AG NÃrnberg)
--