Messages in this thread | | | Date | Tue, 16 Sep 2008 17:52:11 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH 0/3] fix GART to respect device's dma_mask about virtual mappings |
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On Tue, Sep 16, 2008 at 10:20:40PM +0900, FUJITA Tomonori wrote: > On Tue, 16 Sep 2008 02:54:32 +0200 > Andi Kleen <andi@firstfloor.org> wrote: > > > FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> writes: > > > > > Currently, gart IOMMU ignores device's dma_mask when it does virtual > > > mappings. So it could give a device a virtual address that the device > > > can't access to. > > > > Huh? That is what the need_iommu() logic in gart_map_sg() > > does. An I'm not aware of any bugs in this area. > > What the need_iommu() does is seeing if GART needs to do virtual > mappings or not. > > (After need_iommu() checking) What this patchset does is to guarantee > that GART provides a virtual address that a device can access to. > > > > Did you actually see that failure in practice? I don't see > > how it could happen. > > No, I did not. This patchset does the right thing theoretically, I > think, but if such problem never happens for GART, I'll drop the patch > for GART. Joerg?
I am not aware of any failures which are fixed by these patches. But in theory there could be failures.
Joerg
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