MIPS: KVM: Fix gfn range check in kseg0 tlb faults

commit 0741f52d1b980dbeb290afe67d88fc2928edd8ab upstream.

Two consecutive gfns are loaded into host TLB, so ensure the range check
isn't off by one if guest_pmap_npages is odd.

Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[james.hogan@imgtec.com: Backport to v3.17.y - v4.4.y]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c
index 59e885fa4c6516e8ddb0c85e593619834e8528c6..836b61aabf8612d8e27d0cbf43ceced6702a5eb2 100644 (file)
--- a/arch/mips/kvm/tlb.c
+++ b/arch/mips/kvm/tlb.c
@@ -276,7 +276,7 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
        }
 
        gfn = (KVM_GUEST_CPHYSADDR(badvaddr) >> PAGE_SHIFT);
-       if (gfn >= kvm->arch.guest_pmap_npages) {
+       if ((gfn | 1) >= kvm->arch.guest_pmap_npages) {
                kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,
                        gfn, badvaddr);
                kvm_mips_dump_host_tlbs();