[Qemu-devel] [PATCH v3 0/3] Add HAX support

[Vincent Palatin]

I took a stab at trying to rebase/upstream the support for Intel HAXM.
(Hardware Accelerated Execution Manager).
Intel HAX is kernel-based hardware acceleration module for Windows and MacOSX.

I have based my work on the last version of the source code I found:
the emu-2.2-release branch in the external/qemu-android repository as used by
the Android emulator.
In patch 2/3, I have forward-ported the core HAX code from there.
It has been modified to build and run along with the current code base.
It has been simplifying by removing non-UG hardware support / Darwin support /
Android-specific leftovers.

CAVEAT: this patchset is still RFC because in addition of potentially containing
a few outdated constructs and a questionable mess in qemu_cpu_kick_thread(),
there are 2 unsolved issues:
- in rare cases, the HAX kernel module asks us to emulate a MMIO access rather
  than just using the 'fast MMIO' path. This path is still not implemented (as
  it was in the original patch). It's unclear why/when this is happening
  (eg you can run a full linux image without hitting it but the default iPXE
  option ROM is hitting it in the Intel network driver).
- the MemoryListener implementation cannot remove a memory mapping (e.g. for
  digging the VGA 'hole' in the lowmem). This shortcoming breaks the std vga
  implementation but in the current HAX module API, I don't see any (documented)
  way of implementing this.

In patch 3/3, I have put the plumbing into the QEMU code base, I did some clean
up there and it is reasonably intrusive: i.e.
 Makefile.target           |  1 +
 configure                 | 18 ++++++++++
 cpus.c                    | 87 ++++++++++++++++++++++++++++++++++++++++++++++-
 exec.c                    | 16 +++++++++
 hw/intc/apic_common.c     |  3 +-
 include/qom/cpu.h         |  5 +++
 include/sysemu/hw_accel.h |  9 +++++
 qemu-options.hx           | 11 ++++++
 target-i386/Makefile.objs |  4 +++
 vl.c                      | 15 ++++++--
 10 files changed, 164 insertions(+), 5 deletions(-)

The patch 1/3 just extracts from KVM specific header the cpu_synchronize_
functions that HAX is also using.

I have tested the end result on a Windows 10 Pro machine (with UG support)
with the Intel HAXM module 6.0.4 and a large ChromiumOS x86_64 image to
exercise various code paths. It looks stable.
I also did a quick regression testing of the integration by running a Linux
build with KVM enabled.
Just running 'qemu-system-x86_64 -enable-hax' is broken due to the caveats
described above.

Changes from v2 to v3:
- fix saving/restoring FPU registers as suggested by Paolo.
- fix Windows build on all targets as contributed by Stefan Weil.
- clean-up IO / MMIO emulation.
- more clean-up of emulation leftovers.

Changes from v1 to v2:
- fix all style issues in the original code to get it through checkpatch.pl.
- remove Darwin support, it was barely tested and not fully functional.
- remove the support for CPU without UG mode.
- fix most review comments

Vincent Palatin (3):
  kvm: move cpu synchronization code
  target-i386: Add Intel HAX files
  Plumb the HAXM-based hardware acceleration support

 Makefile.target             |    1 +
 configure                   |   18 +
 cpus.c                      |   88 ++-
 exec.c                      |   16 +
 gdbstub.c                   |    1 +
 hax-stub.c                  |   39 ++
 hw/i386/kvm/apic.c          |    1 +
 hw/i386/kvmvapic.c          |    1 +
 hw/intc/apic_common.c       |    3 +-
 hw/misc/vmport.c            |    2 +-
 hw/ppc/pnv_xscom.c          |    2 +-
 hw/ppc/ppce500_spin.c       |    4 +-
 hw/ppc/spapr.c              |    2 +-
 hw/ppc/spapr_hcall.c        |    2 +-
 hw/s390x/s390-pci-inst.c    |    1 +
 include/qom/cpu.h           |    5 +
 include/sysemu/hax.h        |   56 ++
 include/sysemu/hw_accel.h   |   48 ++
 include/sysemu/kvm.h        |   23 -
 monitor.c                   |    2 +-
 qemu-options.hx             |   11 +
 qom/cpu.c                   |    2 +-
 target-arm/cpu.c            |    2 +-
 target-i386/Makefile.objs   |    4 +
 target-i386/hax-all.c       | 1250 +++++++++++++++++++++++++++++++++++++++++++
 target-i386/hax-i386.h      |   85 +++
 target-i386/hax-interface.h |  357 ++++++++++++
 target-i386/hax-slot.c      |  333 ++++++++++++
 target-i386/hax-slot.h      |   58 ++
 target-i386/hax-windows.c   |  489 +++++++++++++++++
 target-i386/hax-windows.h   |   89 +++
 target-i386/helper.c        |    1 +
 target-i386/kvm.c           |    1 +
 target-ppc/mmu-hash64.c     |    2 +-
 target-ppc/translate_init.c |    2 +-
 target-s390x/gdbstub.c      |    1 +
 vl.c                        |   15 +-
 37 files changed, 2978 insertions(+), 39 deletions(-)
 create mode 100644 hax-stub.c
 create mode 100644 include/sysemu/hax.h
 create mode 100644 include/sysemu/hw_accel.h
 create mode 100644 target-i386/hax-all.c
 create mode 100644 target-i386/hax-i386.h
 create mode 100644 target-i386/hax-interface.h
 create mode 100644 target-i386/hax-slot.c
 create mode 100644 target-i386/hax-slot.h
 create mode 100644 target-i386/hax-windows.c
 create mode 100644 target-i386/hax-windows.h

-- 
2.8.0.rc3.226.g39d4020