[PATCH v12] claim and its friends for allocating multiple self-ballooning guests (v12).

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

Changes since v11:
 - Removed most of the libxl_types.idl changes,
 - Rewrote most of the comments,
 - Added support for dealing with out-of-sync hypervisors,,,,
 - claim_mode is now a boolean,
 - xl info will print outstanding_pages if claim_mode is set to 1,
 - Addressed all (I hope?) Ian's comments.

The patch (mmu: Introduce XENMEM_claim_pages (subop of memory ops) is already in the
hypervisor and described in details the problem/solution/alternative solutions.
This builds upon that new hypercall to expand the toolstack to use it.

The patches follow the normal code-flow - the patch to implement the two hypercalls:
XENMEM_claim_pages and XENMEM_get_outstanding_pages.

Then the patches to utilize them in the libxc. The hypercall's are only utilized
if the toolstack (libxl) sets the claim_mode to 1 (true).

Then the toolstack (libxl + xl) patches. They revolve around two different changes:
 1). Add 'claim_mode=0|1' global configuration value that determines
     whether the claim hypercall should be used as part of guest creation.
 2). As part of  'xl info' output how many pages are claimed by different guests.
     This is more of a diagnostic patch.

Note that these two pages:
 [PATCH 2/4] xc: export outstanding_pages value in xc_dominfo
 [PATCH 3/4] xl: export 'outstanding_pages' value from xcinfo

could very well be squashed together. I don't know whather that is OK with
the maintainers or not so I left them as two seperate ones. I am OK with
them being squashed.

 docs/man/xl.conf.pod.5      | 41 +++++++++++++++++++++++++++++++++++++++++
 tools/examples/xl.conf      |  6 ++++++
 tools/libxc/xc_domain.c     |  1 +
 tools/libxc/xenctrl.h       |  1 +
 tools/libxl/libxl.c         | 13 +++++++++++++
 tools/libxl/libxl.h         |  2 +-
 tools/libxl/libxl_dom.c     |  3 ++-
 tools/libxl/libxl_types.idl |  3 ++-
 tools/libxl/xl.c            |  5 +++++
 tools/libxl/xl.h            |  1 +
 tools/libxl/xl_cmdimpl.c    | 26 ++++++++++++++++++++++++++
 11 files changed, 99 insertions(+), 3 deletions(-)

Dan Magenheimer (1):
      xc: export outstanding_pages value in xc_dominfo structure.

Konrad Rzeszutek Wilk (3):
      xl: Implement XENMEM_claim_pages support via 'claim_mode' global config
      xl: export 'outstanding_pages' value from xcinfo
      xl: 'xl info' print outstanding claims if enabled (claim_mode=1 in xl.conf)