On Wed, 2010-10-20 at 15:43 +0200, Michael S. Tsirkin wrote: > On Wed, Oct 20, 2010 at 12:59:42PM +0200, Avi Kivity wrote: > > How far away is vfio? If it's merged soon, we might avoid making > > changes to the old assigned device infrastructure and instead update > > vfio. > > Hard to be sure, hopefully 2.6.38 material. > > Some issues off the top of my head are > - readonly/virtualized table correctness > hopefully will start converging now that > we are switching to standard registers from pci_regs.h > - work out some capability negotiation mechanism so userspace/kernel > can detect bug fixes/missing features and recover or fail gracefully > - with multiple assigned devices in a guest: > I don't think we have figured out how do they share an iommu context A single UIOMMU fd can be used for multiple devices. The code I wrote supports this, but it's really only meant to support a uiommufd passed via the command line for libvirt usage. Since libvirt doesn't yet support vfio, it's never been tested. > - maybe: reset handling (flr support) - need to look a it I'd add that for the qemu vfio driver, we need to work out the KVM interrupt optimizations, otherwise we suffer extra latency vs current code. > > > On the other hand, changes to the old infrastructure are much > > more amenable to backporting for long term support distro kernels, > > so we may need to actively develop both for a while. Yep, I think we'll need to continue development and probably maintain them both for a while. Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
