[PATCH v2 0/5] xen: grant table interface v2 support

[Juergen Gross <jgross@suse.com>]

In order to support Linux to run as a pv guest on machines with huge
memory (>16TB) or as a hvm guest with more than 16TB of memory the
kernel has to support grant table interface v2, as v1 is limited to
32 bit frame numbers.

This series re-adds that support (it has been removed in 2015) and
restricts usage of v2 to the features of v1 in order to support
migration to hosts which only support v1.

V2 is selected only in the following cases:
- the user has specified v2 via module parameter
- in a pv guest if the maximum possible memory address of the host is
  above 16TB (memory hotplug taken into account)
- in a hvm guest if the maximum guest memory address is above 16TB
  (again with memory hotplug taken into account)

Changes in V2:
- patch 2: remove update_trans_entry() from gnttab_ops (Boris Ostrovsky)
- added new patch 4
- patch 5: use cpuid on pv and max_possible_pfn on hvm for version select

Juergen Gross (5):
  xen: re-introduce support for grant v2 interface
  xen: limit grant v2 interface to the v1 functionality
  xen: add grant interface version dependent constants to gnttab_ops
  xen: update arch/x86/include/asm/xen/cpuid.h
  xen: select grant interface version

 arch/arm/xen/grant-table.c       |   9 +-
 arch/x86/include/asm/xen/cpuid.h |  42 +++++--
 arch/x86/xen/grant-table.c       |  60 +++++++++-
 drivers/xen/grant-table.c        | 244 +++++++++++++++++++++++++++++++++++----
 include/xen/grant_table.h        |   5 +-
 5 files changed, 318 insertions(+), 42 deletions(-)

-- 
2.12.3