Re: [Qemu-devel] [PATCH v3 00/11] igd passthrough chipset tweaks

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jan 05, 2016 at 12:41:27PM +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> We have some code in our tree to support pci passthrough of intel
> graphics devices (igd) on xen, which requires some chipset tweaks
> for (a) the host bridge and (b) the lpc/isa-bridge to meat the
> expectations of the guest driver.
> 
> For kvm we need pretty much the same, also the requirements for vgpu
> (xengt/kvmgt) are very simliar.  This patch wires up the existing
> support for kvm.  It also brings a bunch of bugfixes and cleanups.
> 
> Unfortunaly the oldish laptop I had planned to use for testing turned
> out to have no working iommu support for igd, so this patch series
> still has seen very light testing only.  Any testing feedback is very
> welcome.

I'm very interested to hear about it too, especially in light of the
fact that config accesses to host seem completely
broken ATM.


> Testing with kvm/i440fx:
>   Add '-M pc,igd-passthru=on' to turn on the chipset tweaks.
>   Passthrough the igd using vfio.
> 
> Testing with kvm/q35:
>   Add '-M q35,igd-passthru=on' to turn on the the chipset tweaks.
>   Pick up the linux kernel patch referenced in patch #11, build a
>   custom kernel with it.  Passthrough the igd using vfio.
> 
> Testing with xen:
>   Existing setups should continue working ;)
> 
> Changes in v3:
>   * Handle igd-passthrough-isa-bridge creation in machine init.
>   * Fix xen build failure.
> 
> Changes in v2:
>   * Added igd-passthrough-isa-bridge support form kvm.
>   * Added patch to drop has_igd_gfx_passthru.
> 
> cheers,
>   Gerd
> 
> Gerd Hoffmann (11):
>   pc: wire up TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE for !xen
>   pc: remove has_igd_gfx_passthru global
>   pc: move igd support code to igd.c
>   igd: switch TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE to realize
>   igd: TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE: call parent realize
>   igd: use defines for standard pci config space offsets
>   igd: revamp host config read
>   igd: add q35 support
>   igd: move igd-passthrough-isa-bridge to igd.c too
>   igd: handle igd-passthrough-isa-bridge setup in realize()
>   igd: move igd-passthrough-isa-bridge creation to machine init
> 
>  hw/i386/pc_piix.c         | 130 +++------------------------------
>  hw/pci-host/Makefile.objs |   3 +
>  hw/pci-host/igd.c         | 181 ++++++++++++++++++++++++++++++++++++++++++++++
>  hw/pci-host/piix.c        |  88 ----------------------
>  hw/pci-host/q35.c         |   6 +-
>  hw/xen/xen_pt.c           |  14 ----
>  hw/xen/xen_pt.h           |   5 +-
>  include/hw/i386/pc.h      |   2 +-
>  vl.c                      |  10 ---
>  9 files changed, 204 insertions(+), 235 deletions(-)
>  create mode 100644 hw/pci-host/igd.c
> 
> -- 
> 1.8.3.1
>