Re: [PATCH 4/4] PF: Async page fault support on s390

From: Gleb Natapov
Date: Thu Jul 11 2013 - 06:58:44 EST


On Thu, Jul 11, 2013 at 12:41:37PM +0200, Christian Borntraeger wrote:
> On 11/07/13 11:04, Gleb Natapov wrote:
> > On Wed, Jul 10, 2013 at 02:59:55PM +0200, Dominik Dingel wrote:
> >> This patch enables async page faults for s390 kvm guests.
> >> It provides the userspace API to enable, disable or get the status of this
> >> feature. Also it includes the diagnose code, called by the guest to enable
> >> async page faults.
> >>
> >> The async page faults will use an already existing guest interface for this
> >> purpose, as described in "CP Programming Services (SC24-6084)".
> >>
> >> Signed-off-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
> > Christian, looks good now?
>
> Looks good, but I just had a discussion with Dominik about several other cases
> (guest driven reboot, qemu driven reboot, life migration). This patch should
> allow all these cases (independent from this patch we need an ioctl to flush the
> list of pending interrupts to do so, but reboot is currently broken in that
> regard anyway - patch is currently being looked at)
>
> We are currently discussion if we should get rid of the APF_STATUS and let
> the kernel wait for outstanding page faults before returning from KVM_RUN
> or if we go with this patch and let userspace wait for completion.
>
> Will discuss this with Dominik, Conny and Alex. So lets defer that till next
> week, ok?
>
Sure.

--
Gleb.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/