On Tue, Apr 18, 2017 at 10:09 AM, Graham Neville <grahamnevi...@gmail.com> wrote: > Has there been any feedback on this at all? > > I'm still struggling to get a Windows and Linux VM working at the same time > with npt=1. Annoying as I'm having to reboot in to a different kernel if I > want to use one or the other. > > Are you able to share your Kernel command line and XML for the Linux host > please? > > > On 7 Apr 2017 22:54, "Nick Sarnie" <commendsar...@gmail.com> wrote: > > I can't reproduce that issue, I tested a Fedora VM with both npt 0 and > 1, of course with the same GPU performance results as windows. I've > mailed some AMD guys and KVM guys, and hopefully someone can at least > figure out what is going on. Also, Alex has reproduced this himself on > both Nvidia and AMD GPUs. > > On Fri, Apr 7, 2017 at 5:49 PM, Graham Neville <grahamnevi...@gmail.com> > wrote: >> Sarnex, >> >> I have similar oddities with npt with Ryzen. As you say with kvm-amd.npt=0 >> the GPU performance is so much better (In my Witcher3 tests I'm going from >> 40fps to 75fps!). However with npt disabled the Windows10 VM slows down an >> awful lot in general tasks. >> >> I've also noticed that I can only run a Linux guest with kvm-amd.npt=0, if >> I >> have it set to enabled then the Linux guest fails to start. I have the >> same >> issue even just trying to install Linux from an ISO, it will crash at the >> GRUB install menu. >> >> Hopefully someone knows a fix for this. >> >> _______________________________________________ >> vfio-users mailing list >> vfio-users@redhat.com >> https://www.redhat.com/mailman/listinfo/vfio-users >> > >
Alex emailed Paolo, the KVM maintainer, some traces but he couldn't find anything in them. Please follow the thread on the iommu mailing list for more details. For now, I think we have to disable NPT. _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
