On Tue, 09 May 2006 00:00:08 -0700, Chris Wright <chrisw@xxxxxxxxxxxx> 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? If a significant tradeoff exists (for example, between performance and maximum addressable memory), then we need to think about the real issue instead of throwing config options into the pot. -- Pete