On Wed, Feb 17, 2010 at 12:27:09PM +0200, Avi Kivity wrote: > On 02/17/2010 11:43 AM, borove@xxxxxxxxxx wrote: > >From: Eran Borovik<borove@xxxxxxxxxx> > > > >This patch adds modifications to allow correct > >balloon operation when a virtual guest uses a direct assigned device. > >The modifications include a new interface between qemu and kvm to allow > >mapping and unmapping the pages from the IOMMU as well as pinning and unpinning as needed. > > The plan for iommu support is to push it into uio. Instead of kvm > managing the iommu directly, I'd like qemu to open a uio device and > set up an iommu mapping there, which will just happen to match the > kvm memory slots. Similarly, interrupts will be forwarded using > irqfds. This will allow using the iommu without kvm, and reduce the > amount of special purpose kvm code. > > These patches make the transition more difficult which worries me. That's a fair point, but they also address a real short-coming of the current device assignment code, which pins all of the guest's memory unconditionally. Unless the uio effort is in progress and expected to complete shortly, I would think the benefit of these simple patches trumps the cost. Cheers, Muli -- 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
