kvm: nVMX: Enforce cpl=0 for VMX instructions

kvm: nVMX: Enforce cpl=0 for VMX instructions

commit 727ba748e110b4de50d142edca9d6a9b7e6111d8 upstream.

VMX instructions executed inside a L1 VM will always trigger a VM exit
even when executed with cpl 3. This means we must perform the
privilege check in software.

Fixes: 70f3aac964ae("kvm: nVMX: Remove superfluous VMX instruction fault checks")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Wilhelm <fwilhelm@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>