The combination of unset CD and set NW bit in CR0 is illegal.
CR0[63:32] are also reserved and need to be zero.
(AMD64 Architecture Programmer's Manual, V2, 15.5)

Signed-off-by: Lara Lazier <laramglazier@gmail.com>
Message-Id: <20210616123907.17765-4-laramglazier@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>