Comment 24 for bug 1788665

It seems that this "bug" affects only 2D-performance mediated through GDI in Windows (CPU-, not GPU-driven). There have been reports that GDI switches a lot between user/kernel space.

Are vmexits triggered when the guest switches from user- to kernel-space? Could this be subsequently causing IRBS swaps and degradation of performance? Then again, "perf kvm --host stat live" doesn't report an increase in vmexits.

It would be interesting to know whether this behavior persists under other hypervisors (ESXi or Windows Server 2016).