migrate PV EOI MSR

It turns out PV EOI gets disabled after migration - until next guest reset.
This is because we are missing code to actually migrate it. This patch fixes it up: it applies cleanly to qemu.git as well as qemu-kvm.git, so I think it's cleaner to apply it in qemu.git to keep diff to minimum.

Note: there's talk about adding infrastructure for CPUID whitelisting which thinkably could be used for migration compat support. I am guessing this won't be 1.2 material - when it's ready we can easily replace a simple flag that this patchset adds with something else.

So this just adds minimal code to avoid regressing cross-version migration.

Note: there's a kernel bug in linux 3.6-rc3 - apply my patch 'kvm: fix KVM_GET_MSR for PV EOI' in order to use this patchset on it.

Needed for 1.2.

Changes from v2 and v3:
Multiple tweaks in variable name to confirm to strict C99 (Blue Swirl)
Changes from v1:
Update all headers from 3.6-rc3 to keep them in sync (Jan) Disable cpuid flag for qemu 1.2 and older (Orit)

Michael S. Tsirkin (4):
linux-headers: update to 3.6-rc3
pc: refactor compat code
cpuid: disable pv eoi for 1.1 and older compat types
kvm: get/set PV EOI MSR

 hw/Makefile.objs                  |  2 +-
 hw/cpu_flags.c                    | 32 +++++++++++++++++++++++++++
 hw/cpu_flags.h                    |  9 ++++++++
 hw/pc_piix.c                      | 46 ++++++++++++++++++++++++++++++++-------
 linux-headers/asm-s390/kvm.h      |  2 +-
 linux-headers/asm-s390/kvm_para.h |  2 +-
 linux-headers/asm-x86/kvm.h       |  1 +
 linux-headers/asm-x86/kvm_para.h  |  7 ++++++
 linux-headers/linux/kvm.h         |  3 +++
 target-i386/cpu.c                 |  8 +++++++
 target-i386/cpu.h                 |  1 +
 target-i386/kvm.c                 | 13 +++++++++++
 target-i386/machine.c             | 21 ++++++++++++++++++
 13 files changed, 136 insertions(+), 11 deletions(-)
 create mode 100644 hw/cpu_flags.c
 create mode 100644 hw/cpu_flags.h

MST