KVM: nVMX: Check HOST_IA32_PERF_GLOBAL_CTRL on VM-Entry

Add a consistency check on nested vm-entry for host's
IA32_PERF_GLOBAL_CTRL from vmcs12. Per Intel's SDM Vol 3 26.2.2:

  If the "load IA32_PERF_GLOBAL_CTRL"
  VM-exit control is 1, bits reserved in the IA32_PERF_GLOBAL_CTRL
  MSR must be 0 in the field for that register"

Suggested-by: Jim Mattson <jmattson@google.com>
Co-developed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>