Subject: Re: [PATCH 3/4] drivers/vfio: New IOCTL command VFIO_EEH_INFO

From: Gavin Shan <[email-masked]>
Date: Wed, 21 May 2014 14:39:07 +1000

On Wed, May 21, 2014 at 10:23:52AM +1000, Benjamin Herrenschmidt wrote:
>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.
>

Yeah, it's another benefit for the approach. I need think about it
later. Thanks, Ben. It's really good point.

>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.
>

Yeah, I'll address the notifier later.

Thanks,
Gavin