tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: pmf(9) and Xen domU suspending?

On Thu, Apr 03, 2008 at 05:50:56PM +0200, Joerg Sonnenberger wrote:
> On Thu, Apr 03, 2008 at 05:03:59PM +0200, Jean-Yves Migeon wrote:
> > I do not know the exact behaviour regarding kernel state for a 
> > suspend-to-RAM. Xen manipulates MMU directly, the domu is not (well, there 
> > are some corner cases like writable page tables, but it adds up complexity 
> > when restoring a VM).
> That's why I was asking about dom0 vs domU. I am not sure if dom0 can be
> done reasonably, but domU doesn't care much (at all?) about the physical
> allocation.
> I would advise you to look at acpi_enter_sleep_state first. Basically,
> for now trigger the suspend via a sysctl. The pmf_system_* calls are for
> suspending devices. The virtual Xen devices should detach themselve from
> the hypervisor on suspend and look for the corresponding new resource on
> resume. For the low level code you might not need to do anything at all,
> but call some function of the hypervisor. I am not sure.

Yes, most of the work is in the frontend device drivers. I think the
frontend's callbacks for suspend should be called from pmf(9), I hope I'm
not wrong about this :)

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference

Home | Main Index | Thread Index | Old Index