On Thu, Mar 22, 2012 at 02:50:25PM +0100, Wei Wang wrote: > On 03/22/2012 03:14 AM, David Gibson wrote: > >Here's another version of my series implementing the nevessary > >framework for emulation of guest-visible IOMMUs. I've incorporated > >the feedback from the last posting. I'm fairly confident that > >preliminary patches 1-3 are ready to go in, the rest might still need > >more consideration. > > > >In particular, if anyone has thoughts on how to handle the case where > >an IOMMU mapping is invalidated by the guest where a qemu-side device > >currently has that piece of IOVA-space dma_memory_map()ed, I'd be > >interested to hear it. > > > > > > > > Hi David, > I am Xen developer. Currently I am working on a hardware based iommu > emulation for amd iommu v2 systems (we need this to enable iommuv2 > drivers in guest OS and therefore to passthroug gpgpu to hvm guest). > In this work, only a virtual iommu device has to be registered on > qemu bus and dma translations are still performed by iommu hardware. > So I wonder if it is possible that I could integrate my work with > yours. I had a proof-of-concept patch for qemu: > > http://lists.xen.org/archives/html/xen-devel/2011-12/msg01269.html > > my last post was: > http://lists.xen.org/archives/html/xen-devel/2012-03/msg00591.html
I'd be very glad to see AMD IOMMU support integrated with my infrastructure. Eduard - Gabriel's original patch series included an AMD IOMMU emulation, but since I'm not really familiar with that IOMMU, and don't have the hardware to test it, I didn't feel confident to attempt porting it to my new infrastructure. I notice that you seem to be aiming mostly at pass-through. Pass-through has some complications of its own - this patch series was aimed firstly at IOMMU emulation, although I'm also concerned with pass-through (we're currently struggling with how best to handle pass-through for pSeries machines). -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson