Messages in this thread | | | Date | Mon, 16 Jan 2017 17:36:55 -0200 | From | Marcelo Tosatti <> | Subject | Re: [patch 3/3] PTP: add kvm PTP driver |
| |
On Mon, Jan 16, 2017 at 07:01:48PM +0100, Radim Krcmar wrote: > > Sorry the clock difference is 10ns now. So the guest clock is off by _10 ns_ > > of the host clock. > > That is pretty good.
Yes.
> > You are suggesting to use getcrosststamp instead, to drop the (rdtsc() - > > guest_tsc) part ? > > Yes, it results in simpler code, doesn't create dependency on the > dreaded kvmclock, and is the best we can currently do wrt. precision.
Sorry, unless i am misunderstanding how this works, it'll get the guest clock 2us behind, which is something not wanted.
Miroslav, if ->gettime64 returns the host realtime at 2us in the past, this means Chrony will sync the guest clock to
host realtime - 2us
Is that correct?
| |