From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [RFC 0/4] Virtio uses DMA API for all devices
Date: Fri, 3 Aug 2018 00:06:38 -0700
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: robh@kernel.org, srikar@linux.vnet.ibm.com, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Will Deacon <will.deacon@arm.com>, linux-kernel@vger.kernel.org, linuxram@us.ibm.com, virtualization@lists.linux-foundation.org, Christoph Hellwig <hch@infradead.org>, paulus@samba.org, marc.zyngier@arm.com, mpe@ellerman.id.au, joe@perches.com, robin.murphy@arm.com, david@gibson.dropbear.id.au, linuxppc-dev@lists.ozlabs.org, elfring@users.sourceforge.net, haren@linux.vnet.ibm.com, Anshuman Khandual <khandual@linux.vnet.ibm.com>
List-Id: virtualization@lists.linuxfoundation.org

On Thu, Aug 02, 2018 at 11:53:08PM +0300, Michael S. Tsirkin wrote:
> > We don't need cache flushing tricks.
> 
> You don't but do real devices on same platform need them?

IBMs power plaforms are always cache coherent.  There are some powerpc
platforms have not cache coherent DMA, but I guess this scheme isn't
intended for them.