• Singh, Brijesh's avatar
    iommu/amd: Clear memory encryption mask from physical address · b3e9b515
    Singh, Brijesh authored
    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: 2543a786 ("iommu/amd: Allow the AMD IOMMU to work with memory encryption")
    Reported-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: Tom Lendacky <thomas.lendacky@amd.com>
    Cc: Joerg Roedel <joro@8bytes.org>
    Cc: <iommu@lists.linux-foundation.org>
    Cc: Borislav Petkov <bp@suse.de>
    Cc: Paolo Bonzini <pbonzini@redhat.com>
    Cc: Radim Krčmář <rkrcmar@redhat.com>
    Cc: kvm@vger.kernel.org
    Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: <stable@vger.kernel.org> # 4.14+
    Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
    Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
    b3e9b515
amd_iommu.c 104 KB