On Tue, Dec 10, 2013 at 02:18:36PM +0100, Paolo Bonzini wrote: > Il 28/11/2013 11:26, Michael S. Tsirkin ha scritto: > > On Mon, Nov 25, 2013 at 06:43:13PM +0100, Paolo Bonzini wrote: > >> v2: condition enablement of new mapping to new machine types (Paolo) > >> v3: fix changelog > >> v4: rebase > >> v5: ensure alignment of piecetwo on 2MB GPA (Igor) > >> do not register zero-sized piece-one (Igor) > >> v6: fix memory leak (Igor) > >> fix integer overflow (Igor) > >> > >> ---- > >> > >> Align guest physical address and host physical address > >> beyond guest 4GB on a 1GB boundary. > >> > >> Otherwise 1GB TLBs cannot be cached for the range. > >> > >> Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com> > >> [Reorganize code, keep same logic. - Paolo] > >> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > >> --- > > > > Applied, thanks. > > As discussed offlist, I'm not sure anymore that this is the right > approach to the problem. No doubt it is very clever, in that it is > absolutely transparent to the guest. However, the non-contiguous > mapping of ram_addr_t makes it more complex to associate the right NUMA > policy to the ranges. > > If we could make a small guset visible change, it would be simpler to > always make the PCI hole 1GB in size; it is currently 256MB for i440FX > and 1.25GB for q35. We can take a look as soon as the SeaBIOS patches > are in to use QEMU-built ACPI tables. > > Paolo
I think giving us the flexibility in selecting size for memory below 4G is nice. So let's do both: apply Marcel's patch for this specific problem, for huge pages, I don't oppose making the guest visible change as well.
