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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Will Deacon <will.deacon@arm.com>
Cc: mark.rutland@arm.com, devicetree@vger.kernel.org,
	pawel.moll@arm.com, virtualization@lists.linux-foundation.org,
	robh+dt@kernel.org, Robin Murphy <robin.murphy@arm.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] virtio: Try to untangle DMA coherency
Date: Fri, 10 Feb 2017 19:16:10 +0200	[thread overview]
Message-ID: <20170210191409-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20170209183118.GI19397@arm.com>

On Thu, Feb 09, 2017 at 06:31:18PM +0000, Will Deacon wrote:
> On ARM (and other archs such as
> Power), having a mismatch between a cacheable and a non-cacheable mapping
> can result in a loss of coherency between the two (for example, if the
> non-cacheable gues accesses bypass the cache, but the cacheable host
> accesses allocate in the cache).

I guess it's an optimization to avoid cache snoops for non-cacheable accesses?

-- 
MST

  parent reply	other threads:[~2017-02-10 17:16 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-01 12:25 [PATCH] virtio: Try to untangle DMA coherency Robin Murphy
2017-02-01 14:57 ` Will Deacon
     [not found]   ` <20170201145711.GC8177-5wv7dgnIgG8@public.gmane.org>
2017-02-01 17:58     ` Rob Herring
     [not found] ` <8a6494f6409c20b4609cd6bdcdd751f68b5c0564.1485951731.git.robin.murphy-5wv7dgnIgG8@public.gmane.org>
2017-02-01 18:09   ` Michael S. Tsirkin
2017-02-01 18:27     ` Will Deacon
     [not found]       ` <20170201182659.GM8177-5wv7dgnIgG8@public.gmane.org>
2017-02-01 19:19         ` Michael S. Tsirkin
     [not found]           ` <20170201210648-mutt-send-email-mst-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2017-02-02 11:26             ` Will Deacon
2017-02-02 13:34               ` Robin Murphy
     [not found]                 ` <bb041fbe-3fde-0dc1-ae28-cca5acfe9dc5-5wv7dgnIgG8@public.gmane.org>
2017-02-02 16:16                   ` Michael S. Tsirkin
     [not found]                     ` <20170202181357-mutt-send-email-mst-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2017-02-02 16:39                       ` Marc Zyngier
     [not found]                         ` <d9732885-7cd2-461c-6812-37581294b47f-5wv7dgnIgG8@public.gmane.org>
2017-02-02 16:44                           ` Michael S. Tsirkin
2017-02-02 16:30                   ` Michael S. Tsirkin
2017-02-02 16:40                     ` Will Deacon
     [not found]                       ` <20170202164049.GI13839-5wv7dgnIgG8@public.gmane.org>
2017-02-02 16:45                         ` Michael S. Tsirkin
2017-02-09 18:17                       ` Michael S. Tsirkin
2017-02-09 18:31                         ` Will Deacon
2017-02-09 18:49                           ` Michael S. Tsirkin
2017-02-09 18:54                             ` Ard Biesheuvel
2017-02-09 18:56                             ` Will Deacon
2017-02-10 17:16                           ` Michael S. Tsirkin [this message]
2017-02-13 11:57                             ` Will Deacon
2017-02-08 12:58           ` Alexander Graf
2017-02-09 20:57             ` Michael S. Tsirkin
2017-02-09 22:20               ` Alexander Graf

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