Hi all,

trying to pass some host device to a KVM guest (for driver hacking), I
ran into massive IRQ sharing issues on the host. Classic device
assignment refuses to work in this case. I remembered uio_pci_generic,
which I thought was once designed to resolve this conflict. But it isn't
used by KVM or qemu, is it?

So I crossed fingers and hacked IRQF_SHARED into
assigned_device_enable_host_intx. Effect as expected: assignment work,
host gets massive hick-ups (the graphic adapter is another user of this
line...).

Are there already VFIO patches ready for testing that work with shared
IRQs as well? And/or would it make sense to integrate IRQ sharing via
PCI-level IRQ masking to the KVM core until VFIO becomes standard?

Jan