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| author | Chris Wright <chrisw@sous-sol.org> | 2011-05-28 13:15:04 -0500 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2011-06-01 12:47:40 +0100 |
| commit | 1c9fc3d11b84fbd0c4f4aa7855702c2a1f098ebb (patch) | |
| tree | c06f2bcc3b5aa5d0cb0869815e6247afc736ea7a | |
| parent | cb452a4040bb051d92e85d6e7eb60c11734c1781 (diff) | |
| download | linux-1c9fc3d11b84fbd0c4f4aa7855702c2a1f098ebb.tar.gz | |
intel-iommu: Dont cache iova above 32bit
Mike Travis and Mike Habeck reported an issue where iova allocation would return a range that was larger than a device's dma mask. https://lkml.org/lkml/2011/3/29/423 The dmar initialization code will reserve all PCI MMIO regions and copy those reservations into a domain specific iova tree. It is possible for one of those regions to be above the dma mask of a device. It is typical to allocate iovas with a 32bit mask (despite device's dma mask possibly being larger) and cache the result until it exhausts the lower 32bit address space. Freeing the iova range that is >= the last iova in the lower 32bit range when there is still an iova above the 32bit range will corrupt the cached iova by pointing it to a region that is above 32bit. If that region is also larger than the device's dma mask, a subsequent allocation will return an unusable iova and cause dma failure. Simply don't cache an iova that is above the 32bit caching boundary. Reported-by: Mike Travis <travis@sgi.com> Reported-by: Mike Habeck <habeck@sgi.com> Cc: stable@kernel.org Acked-by: Mike Travis <travis@sgi.com> Tested-by: Mike Habeck <habeck@sgi.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| -rw-r--r-- | drivers/pci/iova.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/pci/iova.c b/drivers/pci/iova.c index 9606e599a475..c5c274ab5c5a 100644 --- a/drivers/pci/iova.c +++ b/drivers/pci/iova.c @@ -63,8 +63,16 @@ __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) curr = iovad->cached32_node; cached_iova = container_of(curr, struct iova, node); - if (free->pfn_lo >= cached_iova->pfn_lo) - iovad->cached32_node = rb_next(&free->node); + if (free->pfn_lo >= cached_iova->pfn_lo) { + struct rb_node *node = rb_next(&free->node); + struct iova *iova = container_of(node, struct iova, node); + + /* only cache if it's below 32bit pfn */ + if (node && iova->pfn_lo < iovad->dma_32bit_pfn) + iovad->cached32_node = node; + else + iovad->cached32_node = NULL; + } } /* Computes the padding size required, to make the |