This is a note to let you know that I've just added the patch titled
intel-iommu: Check for identity mapping candidate using
to the 2.6.39-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
intel-iommu-check-for-identity-mapping-candidate-using.patch
and it can be found in the queue-2.6.39 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 8fcc5372fbac085199d84a880503ed67aba3fe49 Mon Sep 17 00:00:00 2001
From: Chris Wright <[email protected]>
Date: Sat, 28 May 2011 13:15:02 -0500
Subject: intel-iommu: Check for identity mapping candidate using
system dma mask
From: Chris Wright <[email protected]>
commit 8fcc5372fbac085199d84a880503ed67aba3fe49 upstream.
The identity mapping code appears to make the assumption that if the
devices dma_mask is greater than 32bits the device can use identity
mapping. But that is not true: take the case where we have a 40bit
device in a 44bit architecture. The device can potentially receive a
physical address that it will truncate and cause incorrect addresses
to be used.
Instead check to see if the device's dma_mask is large enough
to address the system's dma_mask.
Signed-off-by: Mike Travis <[email protected]>
Reviewed-by: Mike Habeck <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/pci/intel-iommu.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2190,8 +2190,19 @@ static int iommu_should_identity_map(str
* Assume that they will -- if they turn out not to be, then we can
* take them out of the 1:1 domain later.
*/
- if (!startup)
- return pdev->dma_mask > DMA_BIT_MASK(32);
+ if (!startup) {
+ /*
+ * If the device's dma_mask is less than the system's memory
+ * size then this is not a candidate for identity mapping.
+ */
+ u64 dma_mask = pdev->dma_mask;
+
+ if (pdev->dev.coherent_dma_mask &&
+ pdev->dev.coherent_dma_mask < dma_mask)
+ dma_mask = pdev->dev.coherent_dma_mask;
+
+ return dma_mask >= dma_get_required_mask(&pdev->dev);
+ }
return 1;
}
Patches currently in stable-queue which might be from [email protected] are
_______________________________________________
stable mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/stable
