https://github.com/torvalds/linux
Revision 910170442944e1f8674fd5ddbeeb8ccd1877ea98 authored by David Woodhouse on 12 September 2016, 02:49:11 UTC, committed by David Woodhouse on 19 November 2016, 17:42:35 UTC
Somehow I ended up with an off-by-three error in calculating the size of
the PASID and PASID State tables, which triggers allocations failures as
those tables unfortunately have to be physically contiguous.

In fact, even the *correct* maximum size of 8MiB is problematic and is
wont to lead to allocation failures. Since I have extracted a promise
that this *will* be fixed in hardware, I'm happy to limit it on the
current hardware to a maximum of 0x20000 PASIDs, which gives us 1MiB
tables — still not ideal, but better than before.

Reported by Mika Kuoppala <mika.kuoppala@linux.intel.com> and also by
Xunlei Pang <xlpang@redhat.com> who submitted a simpler patch to fix
only the allocation (and not the free) to the "correct" limit... which
was still problematic.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: stable@vger.kernel.org
1 parent 1c38718
History
Tip revision: 910170442944e1f8674fd5ddbeeb8ccd1877ea98 authored by David Woodhouse on 12 September 2016, 02:49:11 UTC
iommu/vt-d: Fix PASID table allocation
Tip revision: 9101704

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