On Tue, 2008-01-15 at 16:57 +0200, Avi Kivity wrote: > Hollis Blanchard wrote: > >> btw, isn't passthrough better handled through the tlb? i.e. actually > >> let the guest access the specially-configured memory? You can have qemu > >> mmap /dev/mem and install it as a memslot, and things should work, no? > >> (well, you might need to set some cachablility flag or other). > >> > > > > Hmm, yes you're right. Of course, qemu offers greater flexibility than > > MMUs (which are limited to page-sized granularity, for example), so it > > might still be useful to have qemu intercede. > > > > > > With the endian-aware instructions that doesn't matter, since you set > the endianness on a per-instruction granularity. And with guest tlb > controlled endianness, surely you get page granularity as well? > > > > Since we're defining a stable ABI, I'd rather have the information > > present than miss it in the future... > > So now the question is, do we see the need for qemu to intercept writes > to pass-through devices? IMO the answer is no. If it doesn't > understand anything about the device, it would be better off doing a > real pass through. If it does understand the device, it should know > which endianness it likes.
OK, I'm willing to go along with this, and hope that we don't run into another use case for an endianness flag in the future. -- Hollis Blanchard IBM Linux Technology Center ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
