To fully support PCI passthrough I've been trying to enable these kernel options:
"Support for DMA Remapping Devices"
"Enable DMA Remapping Devices"
"Support for Interrupt Remapping"
as suggested at http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM
However, these options are not visible in make menuconfig when following this guide: https://wiki.debian.org/HowToRebuildAnOfficialDebianKernelPackage
I'm recompiling version 3.2.51, and I've skipped parts of the compilation guide that didn't seem relevant, namely updating the changelog (I did change abiname to prevent module conflicts and such), patching the kernel and building all kernel-related packages (do I need to do this one? It seems to be a distinct process).