Patch "iommu/io-pgtable-arm: Fix iova_to_phys for block entries" has been added to the 4.7-stable tree

Patch "iommu/io-pgtable-arm: Fix iova_to_phys for block entries" has been added to the 4.7-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    iommu/io-pgtable-arm: Fix iova_to_phys for block entries

to the 4.7-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:
     iommu-io-pgtable-arm-fix-iova_to_phys-for-block-entries.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 7c6d90e2bb1a98b86d73b9e8ab4d97ed5507e37c Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Thu, 16 Jun 2016 18:21:19 +0100
Subject: iommu/io-pgtable-arm: Fix iova_to_phys for block entries

From: Will Deacon <will.deacon@arm.com>

commit 7c6d90e2bb1a98b86d73b9e8ab4d97ed5507e37c upstream.

The implementation of iova_to_phys for the long-descriptor ARM
io-pgtable code always masks with the granule size when inserting the
low virtual address bits into the physical address determined from the
page tables. In cases where the leaf entry is found before the final
level of table (i.e. due to a block mapping), this results in rounding
down to the bottom page of the block mapping. Consequently, the physical
address range batching in the vfio_unmap_unpin is defeated and we end
up taking the long way home.

This patch fixes the problem by masking the virtual address with the
appropriate mask for the level at which the leaf descriptor is located.
The short-descriptor code already gets this right, so no change is
needed there.

Reported-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iommu/io-pgtable-arm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -576,7 +576,7 @@ static phys_addr_t arm_lpae_iova_to_phys
 	return 0;
 
 found_translation:
-	iova &= (ARM_LPAE_GRANULE(data) - 1);
+	iova &= (ARM_LPAE_BLOCK_SIZE(lvl, data) - 1);
 	return ((phys_addr_t)iopte_to_pfn(pte,data) << data->pg_shift) | iova;
 }
 


Patches currently in stable-queue which might be from will.deacon@arm.com are

queue-4.7/iommu-io-pgtable-arm-fix-iova_to_phys-for-block-entries.patch
queue-4.7/arm64-hibernate-handle-allocation-failures.patch
queue-4.7/arm64-hibernate-avoid-potential-tlb-conflict.patch
queue-4.7/arm64-debug-unmask-pstate.d-earlier.patch
queue-4.7/arm64-fix-incorrect-per-cpu-usage-for-boot-cpu.patch
queue-4.7/arm64-honor-nosmp-kernel-command-line-option.patch
queue-4.7/arm64-vmlinux.lds-make-__rela_offset-and-__dynsym_offset-absolute.patch
queue-4.7/arm64-mm-avoid-fdt_check_header-before-the-fdt-is-fully-mapped.patch