Re: [Qemu-devel] [PATCH rebased for-1.8] i386: pc: align gpa<->hpa on 1GB boundary (v6)

[Paolo Bonzini <pbonzini@redhat.com>]

Il 11/12/2013 16:45, Igor Mammedov ha scritto:
>> > I'm not sure if it is fixable.  You need a 2M mountpoint to bind the 3G-4G
>> > range correctly, a 1G mountpoint for everything else, and QEMU only allows
>> > to specify one path.
> we could do it with hugepage memdev backend.
> something like:
> 
> -object hugepage-ram,id=mem1gb,size=3G,host-node=0,mem-path=/1gb-hugepage-fs
> -device dimm,id=hp1g,memdev=mem1gb,node=0
> -object hugepage-ram,id=mem2mb,size=500Mb,host-node=1,mem-path=/2mb-hugepage-fs
> -device dimm,id=hp2mb,memdev=mem2mb,node=1
> 
> that basically would allow to distribute initial memory in any way user would
> like.

If you allow for DIMMs, you can just use a small initial amount of
memory (2GB), and cold-plug DIMMs at 4GB.  Then you get exactly the same
result as Gerd's patch. :)

But the beauty of Marcelo's idea was that the user didn't need to do
anything, and the guest did not see anything.  It's a great approach for
backwards-compatibility, no doubt about that.

Paolo