From: Christoph Hellwig <hch@infradead.org>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Christoph Hellwig <hch@infradead.org>, linuxppc-dev@lists.ozlabs.org
Subject: Re: question on "powerpc/pseries/dma: Allow SWIOTLB"
Date: Fri, 19 Jul 2019 00:53:48 -0700 [thread overview]
Message-ID: <20190719075348.GA2892@infradead.org> (raw)
In-Reply-To: <0f969485-a3fe-4436-a448-5f4c4f875cb2@ozlabs.ru>
On Fri, Jul 19, 2019 at 05:52:37PM +1000, Alexey Kardashevskiy wrote:
>
>
> On 19/07/2019 17:10, Christoph Hellwig wrote:
> > Hey Alexey,
> >
> > what is the use case for the above commit? Shouldn't we handle all
> > addressing limits using the iommu?
>
> Our secure VMs is the use case, when only a fraction of system memory is
> available for DMA.
But shouldn't we force usage of the direct ops in that case as the
IOMMU is not neededed at all? Also isn't that support non-upstream so
far?
next prev parent reply other threads:[~2019-07-19 7:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 7:10 question on "powerpc/pseries/dma: Allow SWIOTLB" Christoph Hellwig
2019-07-19 7:52 ` Alexey Kardashevskiy
2019-07-19 7:53 ` Christoph Hellwig [this message]
2019-07-19 8:00 ` Alexey Kardashevskiy
2019-07-19 8:05 ` Christoph Hellwig
2019-07-19 8:23 ` Alexey Kardashevskiy
2019-07-19 12:25 ` Christoph Hellwig
2019-07-20 11:22 ` Alexey Kardashevskiy
2019-07-22 9:23 ` Christoph Hellwig
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