[v4][PATCH 0/5] xen: add Intel IGD passthrough support

[Tiejun Chen <tiejun.chen@intel.com>]

v4:

* Fix some typos in the patch head description.
* Improve some comments.
* Given that xen_pt_register_vga_regions()/xen_pt_unregister_vga_regions()
  are called unconditionally, so we just return 0 there.
* Remove one spurious change.
* Remove some unnecessary "return" in void foo().
* Given that pci_create_pch() is called unconditionally, so we just return 0
  even if its failed to check xen_has_gfx_passthru.
* Use (xen_enabled() && xen_has_gfx_passthru) to make sure we only work
  in this scenario.

v3:

* In this case, as we discussed we will give priority to devices to
  reserve a specific devfn by passing
  "device_model_args_hvm = ['-device', 'xen-platform,addr=0x3']" and
  "vga=none", so withdraw patch #1, #2 and #4.
* Fix some typos.
* Add more comments to make that readable.
* To unmap igd_opregion when call xen_pt_unregister_vga_regions().
* Improve some return paths.
* Force to convert igd_guest/host_opoegion as an unsigned long type
  while calling xc_domain_memory_mapping().
* We need to map 3 pages for opregion as hvmloader set.

v2:

* rebase on current qemu tree.
* retrieve VGA bios from sysfs properly.
* redefine some function name.
* introduce bitmap to manage registe/runregister pci dev, and provide
  a common way to reserve some specific devfn.
* introduce is_igd_passthrough() to make sure we touch physical host
  bridge only in IGD case.
* We should return zero as an invalid address value while calling
  igd_read_opregion().

Additionally, now its also not necessary to recompile seabios with some
extra steps like v1.
 

The following patches are ported partially from Xen Qemu-traditional
branch which are adding Intel IGD passthrough supporting to Qemu upstream.

To pass through IGD to guest, user need to add following lines in Xen config
file:
gfx_passthru=1
pci=['00:02.0 <at> 2']

Now successfully boot Ubuntu 14.04 guests with IGD assigned in Haswell
desktop with Latest Xen + Qemu upstream.

----------------------------------------------------------------
Tiejun Chen (2):
      xen, gfx passthrough: create intel isa bridge
      xen, gfx passthrough: create host bridge to passthrough
 
Yang Zhang (3):
      xen, gfx passthrough: basic graphics passthrough support
      xen, gfx passthrough: support Intel IGD passthrough with VT-D
      xen, gfx passthrough: add opregion mapping
 
 hw/pci-host/piix.c           |  56 +++++++++++++-
 hw/xen/Makefile.objs         |   2 +-
 hw/xen/xen-host-pci-device.c |   5 ++
 hw/xen/xen-host-pci-device.h |   1 +
 hw/xen/xen_pt.c              |  10 +++
 hw/xen/xen_pt.h              |  12 ++-
 hw/xen/xen_pt_config_init.c  |  50 ++++++++++++-
 hw/xen/xen_pt_graphics.c     | 517 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-options.hx              |   9 +++
 vl.c                         |  10 +++
 10 files changed, 667 insertions(+), 5 deletions(-)
 create mode 100644 hw/xen/xen_pt_graphics.c

Thanks
Tiejun