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Subject: Re: [PATCH 3/4] drivers/vfio: New IOCTL command VFIO_EEH_INFO
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Gavin Shan <gwshan@linux.vnet.ibm.com>
Date: Wed, 21 May 2014 10:23:52 +1000
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Cc: aik@ozlabs.ru, Alexander Graf <agraf@suse.de>, kvm-ppc@vger.kernel.org,
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On Tue, 2014-05-20 at 22:39 +1000, Gavin Shan wrote:
> >>Yeah. How about this? :-)
> >>
> >>- Move eeh-vfio.c to drivers/vfio/pci/
> >>- From eeh-vfio.c, dereference arch/powerpc/kernel/eeh.c::eeh_ops, which
> >>   is arch/powerpc/plaforms/powernv/eeh-powernv.c::powernv_eeh_ops. Call
> >
> >Hrm, I think it'd be nicer to just export individual functions that
> >do thing you want to do from eeh.c.
> >
> 
> Ok. Got it. Thanks for your comments :)

The interesting thing with this approach is that VFIO per-se can work
with EEH RTAS backend too in the host.

IE, with PR KVM for example or with non-KVM uses of VFIO, it would be
possible to use a device in a user process and exploit EEH even when
running under a PAPR hypervisor.

That is, vfio-eeh uses "generic" exported EEH APIs from the EEH core
that will work on both powernv and RTAS backends.

Note to Alex: This definitely kills the notifier idea for now though,
at least as a first class citizen of the design. We can add it as an
optional optimization on top later.

Cheers,
Ben.