Messages in this thread | | | Date | Tue, 13 Nov 2007 16:44:43 +0200 | From | Avi Kivity <> | Subject | Re: [PATCH 2/3] kvmclock - the host part. |
| |
Glauber de Oliveira Costa wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Avi Kivity escreveu: > >> Glauber de Oliveira Costa wrote: >> >>> This is the host part of kvm clocksource implementation. As it does >>> not include clockevents, it is a fairly simple implementation. We >>> only have to register a per-vcpu area, and start writting to it >>> periodically. >>> >>> >>> >> Missing live migration support (a way for userspace to read and write >> the guest clock address). Should probably be in a separate patch. >> > > I think it's a matter of issuing a hypercall for reading the clock > address. It's fair simple, and can be done in a later version of this patch. > As for writting, the register hypercall itself can be used. It has no > special side-effects we should care about. >
kvm live migration is done (at least thus far) without guest involvement. So you need the host to be able to transfer this state.
> >>> @@ -1924,6 +1955,7 @@ out: >>> goto preempted; >>> } >>> >>> + kvm_write_guest_time(vcpu); >>> post_kvm_run_save(vcpu, kvm_run); >>> >>> >> Why here? Seems like we're leaving the guest for a while at this place. >> >> Suggest putting it on top of __vcpu_run(), guarded by a flag, and >> setting the flag every time we put the vcpu. >> > > No special preference. It just sounded exity enough to me. I can move to > where you suggest. > >
It's more than a place, it's a set of rules:
- if the vcpu is migrated, we need a new timebase - ditto if we're descheduled (well that's the same thing) - if "some time passes"
-- error compiling committee.c: too many arguments to function
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |