On Tue, Dec 10, 2013 at 03:21:44PM -0200, Marcelo Tosatti wrote: > On Tue, Dec 10, 2013 at 01:05:42PM -0200, Marcelo Tosatti wrote: > > 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. > > > > Please explain what is the difference, and why the complexity does not > > exist with non-contiguous mapping of ram_addr_t. > > You are right - it forces the 1GB page which contains the hole > to be on the same NUMA node as the tail 1GB page - otherwise > incorrect NUMA assignment is not possible.
What does this phrase mean? Are we all in agreement that we want this patch, in addition to resizing below 4g memory? > > Agreed. > > > > 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