evo85

I realize this is YEARS later, but in case it helps someone else... in my case (debian host, win10 guest + Nvidia GTX 1650 GPU passthrough), setting cache=unsafe for the disk drives gave me a smooth experience. It was actually the disk cache causing stuttering. The stuttering was barely noticeable when I turned off passthrough and used VNC instead, so I assumed it was GPU related. However, the resolution shows that GPU passthrough was just causing more context switches for interrupt handling, or some other load, so that the existing level of disk accesses became problematic. I also configured MSI based interrupts via the registry and I believe it also required installing the Nvidia Control Panel, i.e. not the minimalist install. Anyway, here's my example for adding a drive in qemu: "qemu-system-x86_64 -drive id=mydisk,cache=unsafe,format=raw,discard=unmap,detect-zeroes=unmap,file=/some/path [etc etc etc]" Similar settings exist for virsh, etc.