Have you tried DPC latency checker from https://www.thesycon.de/eng/latency_check.shtml ? It might be some "rogue" driver causing issues, on my computer I had to tweak nVidia a little bit to stop polling power all the time. Perhaps AMD is doing something similar?
B. -- Bronek Kozicki b...@incorrekt.com On Tue, 25 Dec 2018, at 4:52 PM, Paige Thompson wrote: > Hi, > > I have a very long standing problem that I've recently been trying to > root cause and document. As near as I can tell the problem is rooted > somewhere in Windows itself and/or the virtio drivers for Windows. I > believe it must be one of the windows virtio drivers because: > > - Both of my DACs work perfectly fine connected to a Windows laptop > running Windows on metal > - A Linux guest with the same VM configuration doesn't have this problem > when using either of my DACs to play back audio > - I've been able to eliminate the problem intermittently on Windows (It > was working fine yesterday until a large batch of Windows Updates were > installed.) > > Even so, I want to know who out there has tried getting a USB audio DAC > to work with a Windows Guest on KVM/QEMU? I'm using a USB3.0 pcie card > that is passed through to the guest, I haven't been able to get it to > work any other way really. > > I've sifted through everything I can possibly for KVM/QEMU to make this > work. In the process I even figured out how to get Q35 to work with my > AMD r9 390 card by virtue of wanting to see if it would solve my problem > however it did not. If I had some other USB audio devices to try I would > but I don't. It'd be nice to find out what others have done to get one > to work as well as it does on bare metal. I think I'm close but I'm not > sure. > > Here is my work log, with a description of what I've tried starting from > the top and towards the end in comments things I have tried changing > along the way: https://gitlab.com/snippets/1789874 > > Most recently I tried reinstalling Windows and using virtio-scsi as the > issue seemed to be related to disk I/O on the host. It was working > really well without any problems at all until windows installed more > updates. In previous attempts I addeed things like isolcpus, hugepages, > increasing the global, emulator, and iothread periods, forcing the timer > to tsc native, etc. I think all of these things in combination has > helped but I'm trying to elliminate the problem completely. Today I > tested it under OpenSuse on linux and that didn't suck at all; works > perfectly on a linux guest. > > > _______________________________________________ > vfio-users mailing list > vfio-users@redhat.com > https://www.redhat.com/mailman/listinfo/vfio-users _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
