KVM: x86: Fix device passthrough when SME is active

commit daaf216c06fba4ee4dc3f62715667da929d68774 upstream.

When using device passthrough with SME active, the MMIO range that is
mapped for the device should not be mapped encrypted.  Add a check in
set_spte() to insure that a page is not mapped encrypted if that page
is a device MMIO page as indicated by kvm_is_mmio_pfn().

Cc: <stable@vger.kernel.org> # 4.14.x-
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 2b6f8a4f2731f273f197d539476e31e11664e260..f438e0c4aa8cda07f6e6c6813f054ad8b020ac92 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2758,8 +2758,10 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
        else
                pte_access &= ~ACC_WRITE_MASK;
 
+       if (!kvm_is_mmio_pfn(pfn))
+               spte |= shadow_me_mask;
+
        spte |= (u64)pfn << PAGE_SHIFT;
-       spte |= shadow_me_mask;
 
        if (pte_access & ACC_WRITE_MASK) {