Empty memory nodes in VNUMA

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

What is the purpose of 'nr_vmemranges < nr_vnodes' test in 
xc_domain_setvnuma()? Can't we have nodes with no memory?

If that's the case, this check will still miss configurations when a 
node spans multiple memory ranges.

For example, this fails:

vcpus = 4
vnuma = [ [ "pnode=0","size=2048","vcpus=0-1" ],
           [ "pnode=1","size=1800" ],
           [ "pnode=2","size=0","vcpus=2-3" ],
           [ "pnode=3","size=100" ] ]

but this

vcpus = 4
vnuma = [ [ "pnode=0","size=2048","vcpus=0-1" ],
           [ "pnode=1","size=1801" ],
           [ "pnode=2","size=0","vcpus=2-3" ],
           [ "pnode=3","size=100" ] ]

does not: because of MMIO hole this will cause a second 1MB range to be 
created on node 1 (in libxl__vnuma_build_vmemrange_hvm()).

Can we drop this check?


-boris