From: Paolo Bonzini pbonzini@redhat.com
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
--- arch/x86/kvm/mmu/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4484,7 +4484,7 @@ __reset_rsvds_bits_mask(struct kvm_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);