UefiCpuPkg/MpInitLib: Always use AP Create if GhcbApicIds HOB is present

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654

Currently, the first time an AP is started for an SEV-SNP guest, it relies
on the VMSA as set by the hypervisor. If the list of APIC IDs has been
retrieved, this is not necessary. The list of APIC IDs will be identified
by a GUIDed HOB. If the GUIDed HOB is present, use the SEV-SNP AP Create
protocol to start the AP for the first time and each time thereafter.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Ray Ni <ray.ni@intel.com>

UefiCpuPkg/Library/MpInitLib/MpLib.h

@@ -2,7 +2,7 @@
   Common header file for MP Initialize Library.
 
   Copyright (c) 2016 - 2023, Intel Corporation. All rights reserved.<BR>
-  Copyright (c) 2020, AMD Inc. All rights reserved.<BR>
+  Copyright (c) 2020 - 2024, AMD Inc. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -924,6 +924,19 @@ SevSnpCreateAP (
   IN INTN         ProcessorNumber
   );
 
+/**
+  Determine if the SEV-SNP AP Create protocol should be used.
+
+  @param[in]  CpuMpData  Pointer to CPU MP Data
+
+  @retval     TRUE       Use SEV-SNP AP Create protocol
+  @retval     FALSE      Do not use SEV-SNP AP Create protocol
+**/
+BOOLEAN
+CanUseSevSnpCreateAP (
+  IN  CPU_MP_DATA  *CpuMpData
+  );
+
 /**
   Get pointer to CPU MP Data structure from GUIDed HOB.