iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page

commit 77a1bce84bba01f3f143d77127b72e872b573795 upstream.

intel_iommu_iova_to_phys() has a bug when it translates an IOVA for a huge
page onto its corresponding physical address. This commit fixes the bug by
accomodating the level of page entry for the IOVA and adds IOVA's lower
address to the physical address.

Cc: <stable@vger.kernel.org>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Yonghyun Hwang <yonghyun@google.com>
Fixes: 3871794642579 ("VT-d: Changes to support KVM")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 5e6c961..2a83fc3 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5144,8 +5144,10 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
        u64 phys = 0;
 
        pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
-       if (pte)
-               phys = dma_pte_addr(pte);
+       if (pte && dma_pte_present(pte))
+               phys = dma_pte_addr(pte) +
+                       (iova & (BIT_MASK(level_to_offset_bits(level) +
+                                               VTD_PAGE_SHIFT) - 1));
 
        return phys;
 }