Re: [libvirt] PATCH: PCI device passthrough in Xen driver

This patch provides initial support for PCI device passthrough in Xen, at time of boot. It does not (yet) implement device hotplug for PCI, since it works in an annoyingly different way to device hotplug of disks & nics. The patch has several aspects - Refactors the pci.c file to make it easier to support both Xen's pci-back.ko and upstream's pcistub.ko, which are almost identical - Add code to pci.c register the PCI device with 'new_slot' before invoking 'bind', since pci-back.ko wants this extra step - In xen_unified.c, add implmentations of APIs to dettach, reattach and reset PCI devices - this just calls into shared pci.c code that QEMU/KVM uses. - In xend_internal.c implement SEXPR conversion. - In xm_internal.c implement parsing of 'pci' config parameter - Add lots of test cases XenD only supports 'unmanaged' PCI devices - ie mgmt app is responsible for detaching/reattaching PCI devices from/to host device drivers. XenD itself won't automatically do this for us, though perhaps someone might like to implement this as an optional feature for XenD, since it is more convenient in some cases.