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Subject: Re: [PATCH v4 0/6] virtio core DMA API conversion
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Andy Lutomirski <luto@amacapital.net>
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On Tue, 2015-11-10 at 10:54 -0800, Andy Lutomirski wrote:
> 
> Does that work on powerpc on existing kernels?
> 
> Anyway, here's another crazy idea: make the quirk assume that the
> IOMMU is bypasses if and only if the weak barriers bit is set on
> systems that are missing the new DT binding.

"New DT bindings" doesn't mean much ... how do we change DT bindings on
existing machines with a FW in flash ?

What about partition <-> partition virtio such as what we could do on
PAPR systems. That would have the weak barrier bit.

Ben.