From: David Woodhouse <dwmw2@infradead.org>
To: Alex Williamson <alex.williamson@hp.com>
Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org
Subject: Re: [PATCH 4/5] intel-iommu: Reinstate RMRRs if a device is removed from passthrough domain
Date: Tue, 27 Oct 2009 08:15:24 +0000 [thread overview]
Message-ID: <1256631324.9814.14.camel@macbook.infradead.org> (raw)
In-Reply-To: <20091026232514.9646.58322.stgit@nehalem.aw>
On Mon, 2009-10-26 at 17:25 -0600, Alex Williamson wrote:
> When a device is setup for passthrough it has full access to memory
> so processing the RMRRs is unnecessary. However, if we remove the device
> from the si_domain, we need to reinstate the associated RMRRs.
>
> Signed-off-by: Alex Williamson <alex.williamson@hp.com>
If your device is doing DMA to host memory autonomously, you may still
have problems with this patch -- you take it out of the si_domain and
then there's a period of time before you reapply the RMRRs, during which
its DMA may be prevented.
You want to set up the new domain first, then switch the device over to
it atomically.
--
David Woodhouse Open Source Technology Centre
David.Woodhouse@intel.com Intel Corporation
next prev parent reply other threads:[~2009-10-27 8:15 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-26 23:24 [PATCH 0/5] intel-iommu fixes Alex Williamson
2009-10-26 23:24 ` [PATCH 1/5] dma: create dma_generic_alloc/free_coherent() Alex Williamson
2009-10-27 0:57 ` Paul Mundt
2009-10-27 2:26 ` Alex Williamson
2009-10-27 1:47 ` FUJITA Tomonori
2009-10-26 23:25 ` [PATCH 2/5] intel-iommu: Use dma_generic_alloc_coherent() for passthrough mappings Alex Williamson
2009-10-27 3:24 ` [PATCH v2 2/5] intel-iommu: Obey coherent_dma_mask for alloc_coherent on passthrough Alex Williamson
2009-10-26 23:25 ` [PATCH 3/5] intel-iommu: Use max_pfn to determine whether a device can passthrough Alex Williamson
2009-10-26 23:25 ` [PATCH 4/5] intel-iommu: Reinstate RMRRs if a device is removed from passthrough domain Alex Williamson
2009-10-27 8:15 ` David Woodhouse [this message]
2009-10-27 15:50 ` Alex Williamson
2009-10-28 14:36 ` David Woodhouse
2009-10-28 16:06 ` Alex Williamson
2009-10-28 20:35 ` Alex Williamson
2009-10-26 23:25 ` [PATCH 5/5] intel-iommu: Quiet unnecessary output Alex Williamson
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