On Tue, Jun 10, 2008 at 09:26:04AM -0500, Anthony Liguori wrote: >> Checking against pfn_valid() isn't enough to differentiate between >> RAM and MMIO areas. I think the consensus was that we also need to >> check PageReserved(), i.e., >> >> if (pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn))) ... >> > > When checking the error return of gfn_to_pfn(), you should use > is_error_pfn(). There's no need to differentiate mmio/ram pages in > the code, the goal is just error checking.
I'd have to check the exact semantics of is_error_pfn() to see if it fits, since strictly speaking what we are doing is not checking pfn_to_page() for errors. We need to differentiate between gfns which represent RAM (which needs to be mapped into the VT-d page tables) and gfns which don't (e.g, slots which represent an MMIO region), which should not be mapped in the VT-d page tables. Cheers, Muli -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
