On Fri, May 8, 2020 at 1:36 PM Jim Mattson <jmattson@xxxxxxxxxx> wrote: > > I'm still not entirely convinced that the Linux hrtimer can be used to > accurately emulate the VMX-preemption timer... It can't, for several reasons: 1) The conversion between wall-clock time and TSC frequency, based on tsc_khz, isn't precise enough. 2) The base clock for the hrtimer, CLOCK_MONOTONIC, can be slewed, whereas the TSC cannot. 3) The VMX-preemption timer is suspended during MWAIT; the hrtimer is not. Is there any reason that VMX-preemption timer emulation shouldn't just be a second client of the hv_timer, along with lapic timer emulation?
