KVM: x86: bit 8 of non-leaf PDPEs is not reserved

commit 5ecad245de2ae23dc4e2dbece92f8ccfbaed2fa7 upstream.

Bit 8 would be the "global" bit, which does not quite make sense for non-leaf
page table entries.  Intel ignores it; AMD ignores it in PDEs and PDPEs, but
reserves it in PML4Es.

Probably, earlier versions of the AMD manual documented it as reserved in PDPEs
as well, and that behavior made it into KVM as well as kvm-unit-tests; fix it.

Cc: stable@vger.kernel.org
Reported-by: Nadav Amit <namit@vmware.com>
Fixes: a0c0feb57992 ("KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD", 2014-09-03)
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 3a281a2decdec3571b4b486c2bb0fc7acbde5df9..73055b8e411f4b12a1bae6999a7ad36d50be1ae9 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3849,7 +3849,7 @@ __reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
                        nonleaf_bit8_rsvd | rsvd_bits(7, 7) |
                        rsvd_bits(maxphyaddr, 51);
                rsvd_check->rsvd_bits_mask[0][2] = exb_bit_rsvd |
-                       nonleaf_bit8_rsvd | gbpages_bit_rsvd |
+                       gbpages_bit_rsvd |
                        rsvd_bits(maxphyaddr, 51);
                rsvd_check->rsvd_bits_mask[0][1] = exb_bit_rsvd |
                        rsvd_bits(maxphyaddr, 51);