Re: [Xen-devel] [PATCH] x86: Allow write-combining on MMIO mappings again

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 26.01.17 at 09:57, <dwmw2@xxxxxxxxxxxxx> wrote:
> Since the fix for XSA-154 in commit c61a6f74f80e ("x86: enforce
> consistent cachability of MMIO mappings"), HVM guests have no longer
> been able to use PAT to obtain write-combining on MMIO because the
> 'ignore PAT' bit is set in EPT.

This is too broad a statement: MMIO pages for which mfn_valid()
is true would still allow WC use.

The only other issue with the patch that I can see is that you need
to eliminate all the hard tabs you're introducing.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel