[PATCH 0 of 3] p2m synchronization second part

[Andres Lagar-Cavilla <andres@lagarcavilla.org>]

In this patch series we add actual synchronization. 

We first refine the API update posted previously (I can fold 
the previous and this first patch together, keep separate, whatever)

Then, we make p2m-lookups actually lock the p2m. For now it's still
the global p2m lock. It can be eventually made more fine grained.

Finally, we ensure that within a get_gfn/put_gfn critical section,
the caller has an additional ref on the underlying mfn. This requires
some trickery for manipulations that remove the mfn or swap it
(sharing).

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>

 xen/arch/x86/hvm/hvm.c        |   3 +-
 xen/arch/x86/mm/p2m.c         |   8 +++---
 xen/common/grant_table.c      |   2 +-
 xen/common/memory.c           |   6 +++-
 xen/arch/x86/mm/mm-locks.h    |  13 +++++----
 xen/arch/x86/mm/p2m.c         |  18 +++++++++++++-
 xen/include/asm-x86/p2m.h     |  39 ++++++++++++++++++-----------
 xen/arch/x86/mm.c             |  18 +++++++++----
 xen/arch/x86/mm/mem_sharing.c |  13 +++------
 xen/arch/x86/mm/p2m.c         |  56 +++++++++++++++++++++++++++++++++++++++++-
 xen/common/grant_table.c      |   4 +-
 xen/common/memory.c           |  10 +++---
 xen/include/asm-x86/mm.h      |   3 +-
 xen/include/asm-x86/p2m.h     |  10 ++++++-
 xen/include/xen/paging.h      |   2 +-
 xen/include/xen/tmem_xen.h    |   2 +-
 16 files changed, 148 insertions(+), 59 deletions(-)