Re: [kvm-devel] [RFC] [VTD][patch 1/3] vt-d support for pci passthrough: kvm-vtd--kernel.patch

[Kay, A. M <all...@in...>]

>We have to ensure we don't swap KVM guest memory while using hardware 
>pass-through, but AFAICT, we do not need to make the memory 
>non-reclaimable  As long as we reprogram the IOMMU with a new, valid, 
>mapping everything should be fine.  mlock() really gives us the right 
>semantics.
>
>Semantically, a PV API that supports DMA window registration simply 
>mlock()s the DMA regions on behalf of the guest.  No special logic 
>should be needed.
>

What should be done for unmodified guest where there is no PV driver in
the guest?  Would a call to mlock() from
qemu/hw/pci-passthrough.c/add_pci_passthrough_device() a reasonable
thing to do?

Allen