So as far as I understand, when you take avx2/fma away from the guest things work, but if you keep them enabled (via cpu model) it fails?
Generally those features should be supported, to most of it they are just processor features and passed through. By Default I think avx2 is passed but fma is not - maybe that was you case. I checked with <cpu mode='host-passthrough'/> to get all I can and then check like /proc/cpuinfo which confirms I have them all. Since this is not emulation I'd hope that KVM itself isn't really involved in doing a lot after setting up initially. Is Radeon crimson relive even supported in a virtual guest? If it freezes what is the qemu status? Maybe check more of the status via https://en.wikibooks.org/wiki/QEMU/Monitor If you would find an equivalent test in a linux guest that I could retry that would very useful. ** Changed in: qemu (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654271 Title: host machine freezes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1654271/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs