OvmfPkg/CpuHotplugSmm: introduce First SMI Handler for hot-added CPUs

Implement the First SMI Handler for hot-added CPUs, in NASM.

Add the interfacing C-language function that the SMM Monarch calls. This
function launches and coordinates SMBASE relocation for a hot-added CPU.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200226221156.29589-13-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf

@@ -24,6 +24,8 @@
 [Sources]
   ApicId.h
   CpuHotplug.c
+  FirstSmiHandler.nasm
+  FirstSmiHandlerContext.h
   PostSmmPen.nasm
   QemuCpuhp.c
   QemuCpuhp.h
@@ -39,9 +41,11 @@
   BaseLib
   BaseMemoryLib
   DebugLib
+  LocalApicLib
   MmServicesTableLib
   PcdLib
   SafeIntLib
+  SynchronizationLib
   UefiDriverEntryPoint
 
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