On 26/06/12 14:48, Christoffer Dall wrote: > On Tue, Jun 26, 2012 at 9:21 AM, Marc Zyngier <marc.zyngier at arm.com> wrote: >> On 25/06/12 22:15, Christoffer Dall wrote: >>>> + cval = ((cycle_t)timer->cntv_cval_high << 32) | timer->cntv_cval_low; >>>> + now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff; >>> >>> when is this adjusted and according to what? >> >> cntvoff is never adjusted. It is sampled exactly once when the VM is >> created, and that's about it. And actually, the feature is disabled for >> the time being. >> > > ok, so the point is simply to say reasonably to the guest it's been > running for X time, not counting time when the guest was not > scheduled? No the point is actually to present the guest with an initial time starting at 0. I thought of using it to present some form of contiguous time to the guest, but putting SMP into the equation hurts so much it's not even funny. You'd end up with vcpus having a different view of time, which may be correct from a relativist point of view, but not something I wish to maintain... ;-) M. -- Jazz is not dead. It just smells funny...
