KVM: nVMX: checks for address bits beyond MAXPHYADDR on VM-entry

On each VM-entry CPU should check the following VMCS fields for zero bits
beyond physical address width:
-  APIC-access address
-  virtual-APIC address
-  posted-interrupt descriptor address
This patch adds these checks required by Intel SDM.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205627.GA1244@gnote>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>