Re: [RFC PATCH 08/35] Add Xen-specific memory management definitions

Chris Wright
2006-05-18T07:39:40Z

* Pete Zaitcev (zaitcev@redhat.com) wrote:
> On Tue, 09 May 2006 00:00:08 -0700, Chris Wright <chrisw@sous-sol.org> wrote:
>
> > +static inline unsigned long pfn_to_mfn(unsigned long pfn)
> > +{
> > +#ifndef CONFIG_XEN_SHADOW_MODE
> > + if (xen_feature(XENFEAT_auto_translated_physmap))
> > + return pfn;
> > + return phys_to_machine_mapping[(unsigned int)(pfn)] &
> > + ~FOREIGN_FRAME_BIT;
> > +#else
> > + return pfn;
> > +#endif
> > +}
>
> Why do we need several modes in Linux guests?

This patchset only supports shadow translated mode, so the extra CONFIG is
just an artifact of this simplied patchset. Ultimately, this is not the
preferred mode (performance wise), but shadow mode is simpler to port to.