Hi,
I have big trouble with qemu linux guest time on my PVE 4.4 : wether with Centos 7 or Debian 8 (kernel 3.10) I see time drift.
NTP is not a solution because drift is too big : it's sound like faster clock.
I tried many tricks I found on forum (HPET, kvm-pit-reinjection, ACPI, etc) but...