On Fri, 30 Jul 2010, Vivek Goyal wrote:
On Fri, Jul 30, 2010 at 11:21:42AM -0700, Eric W. Biederman wrote:
David Woodhouse <dw...@infradead.org> writes:
On Thu, 2010-07-29 at 21:41 -0700, Eric W. Biederman wrote:
There isn't a bus master shut off at the core level.
Effectively, there is if you have an IOMMU.
Depends on the IOMMU. There are several dinky IOMMUs that when you
shut them off DMA simply goes around them, and is not stopped.
I think last time we were discussing this for AMD IOMMU where if you
disable IOMMU, it just kind of become pass through with 1:1 mapping of
addresses.
Yeah, don't do that. The IOMMU should be *on*, but without any active
mappings set up. Which is exactly how Linux will set it up at boot.
--
dwmw2
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