xen: Support PCI passthrough.

Previous commit reverted Xen back to 4.0.3 because xend from 4.1.* and newer
hangs for unknown reasons.
The new "xl" toolstack from 4.1.* and unstable works, yet PCI passthrough is not
supported by xl in 4.1.* and is broken in the unstable.

With this patch I was able to passthrough ATI Radeon HD 6950 without 3D
acceleration, though, to both Linux and Windows guests. Which is the best
archived result with Xen PCI passthrough on NixOS after trying out all possible
Xen versions.
Same VGA card works fine if passed through into a guest with KVM (acceleration,
GPGPU, everything works). I should have tried KVM from the start.

1 files changed, 3 insertions, 0 deletions

diff --git a/pkgs/applications/virtualization/xen/default.nix b/pkgs/applications/virtualization/xen/default.nix
index ce799242e12e..3cb16a6b4425 100644
--- a/pkgs/applications/virtualization/xen/default.nix
+++ b/pkgs/applications/virtualization/xen/default.nix
@@ -79,6 +79,9 @@ stdenv.mkDerivation {
       substituteInPlace tools/xenstat/Makefile \
         --replace /usr/include/curses.h ${ncurses}/include/curses.h
 
+      substituteInPlace tools/ioemu-qemu-xen/xen-hooks.mak \
+        --replace /usr/include/pci ${pciutils}/include/pci
+
       # Work around a bug in our GCC wrapper: `gcc -MF foo -v' doesn't
       # print the GCC version number properly.
       substituteInPlace xen/Makefile \