Lately tsc page was implemented but filled with empty
values. This patch setup tsc page scale and offset based
on vcpu tsc, tsc_khz and HV_X64_MSR_TIME_REF_COUNT value.
The valid tsc page drops HV_X64_MSR_TIME_REF_COUNT msr
reads count to zero which potentially improves performance.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Peter Hornyack <peterhornyack@google.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org>
[Computation of TSC page parameters rewritten to use the Linux timekeeper
parameters. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>