From b3e9b515b08e407ab3a026dc2e4d935c48d05f69 Mon Sep 17 00:00:00 2001 From: "Singh, Brijesh" Date: Thu, 4 Oct 2018 21:40:23 +0000 Subject: [PATCH] iommu/amd: Clear memory encryption mask from physical address MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Boris Ostrovsky reported a memory leak with device passthrough when SME is active. The VFIO driver uses iommu_iova_to_phys() to get the physical address for an iova. This physical address is later passed into vfio_unmap_unpin() to unpin the memory. The vfio_unmap_unpin() uses pfn_valid() before unpinning the memory. The pfn_valid() check was failing because encryption mask was part of the physical address returned. This resulted in the memory not being unpinned and therefore leaked after the guest terminates. The memory encryption mask must be cleared from the physical address in iommu_iova_to_phys(). Fixes: 2543a786aa25 ("iommu/amd: Allow the AMD IOMMU to work with memory encryption") Reported-by: Boris Ostrovsky Cc: Tom Lendacky Cc: Joerg Roedel Cc: Cc: Borislav Petkov Cc: Paolo Bonzini Cc: Radim Krčmář Cc: kvm@vger.kernel.org Cc: Boris Ostrovsky Cc: # 4.14+ Signed-off-by: Brijesh Singh Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 73e47d93e7a0..bee0dfb7b93b 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -3069,7 +3069,7 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom, return 0; offset_mask = pte_pgsize - 1; - __pte = *pte & PM_ADDR_MASK; + __pte = __sme_clr(*pte & PM_ADDR_MASK); return (__pte & ~offset_mask) | (iova & offset_mask); } -- 2.39.5