> > > >> + > >> /* > >> * These 2 parameters are used to config the controls for Pause-Loop Exiting: > >> * ple_gap: upper bound on the amount of time between two successive > >> @@ -622,6 +642,41 @@ static inline bool report_flexpriority(void) > >> return flexpriority_enabled; > >> } > > > > One thing that seems to be missing is removing MSRs from the > > permission bitmap or resetting the permission bitmap to its original > > state before adding changes on top of it. This would be needed on > > subsequent calls to kvm_vm_ioctl_set_msr_filter(). When that happens > > the original changes made by KVM_REQ_MSR_FILTER_CHANGED need to be > > backed out before applying the new set. > > I'm not sure I follow. Subsequent calls to set_msr_filter() will invoke > the "please reset the whole MSR passthrough bitmap to a consistent > state" which will then reapply the in-kvm desired state through the > bitmap and filter state on top on each of those. > Yes, you're correct. I discovered this after the fact by adding a test to the selftest I wrote for the deny list system which I revamped to work for your filter system. It proved the permission bitmaps are in fact set as expected on subsequent calls. You can disregard this comment. As a side note, I'm happy to share the test if you'd like. I also used it to uncover an issue in the first commit of this series.
