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From:   Tom Murphy <tmurphy@arista.com>
Date:   Wed, 24 Apr 2019 17:25:29 +0100
Message-ID: <CAPL0++7G-=FChbMnHoDfh=SnUW3B3YGi-z7Wy9Dq2D6zzQshOg@mail.gmail.com>
Subject: Re: [PATCH] iommu/amd: flush not present cache in iommu_map_page
To:     Joerg Roedel <joro@8bytes.org>
Cc:     Christoph Hellwig <hch@infradead.org>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        Tom Murphy <murphyt7@tcd.ie>
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On Wed, Apr 24, 2019 at 4:55 PM Joerg Roedel <joro@8bytes.org> wrote:
>
> On Wed, Apr 24, 2019 at 07:58:19AM -0700, Christoph Hellwig wrote:
> > I'd be tempted to do that.  But lets just ask Joerg if he has
> > any opinion..
>
> The reason was that it is an unlikely path, as hardware implementations
> are not allowed to set this bit. It is purely for emulated AMD IOMMUs.
> I have not measured whether this annotation has any performance
> benefit, but I find it more readable at least.

In that case I will keep it in.

>
> Regards,
>
>         Joerg
>
> PS: Why did you drop me from the Cc list of the previous replies?