Hi,
I've been looking at PCI passthrough using vfio-pci and hoping that it can
use the Intel IOMMU emulation in the guest to pin-pages in an on-demand
nature, rather than pinning the entire guest memory as vfio-pci does now.
Unfortunately vfio-pci and the intel iommu virtualization don't seem to
play nicely together.
One problem is math overflow in vfio_listener_region_add() where a
type=iommu add is requested for size == 1<<64 after the call to
vfio_initfn().
If I try to fix this, I'm not sure what the call to
vfio_listener_region_add for the entire iommu space (0 -> 1<<64) should
actually do. Should it just skip this region add?
Or maybe the vfio code doesn't handle virtualized real IOMMUs? The comment
in vfio_listener_region_add() makes me wonder:
*
* FIXME: For VFIO iommu types which have KVM acceleration to
* avoid bouncing all map/unmaps through qemu this way, this
* would be the right place to wire that up (tell the KVM
* device emulation the VFIO iommu handles to use).
*/
mh
--
Martin Hicks P.Eng. | m...@bork.org
Bork Consulting Inc. | +1 (613) 266-2296
