OvmfPkg/XenPlatformPei: Introduce XenHvmloaderDetected

This new XenHvmloaderDetected() return true if the hvmloader firmware
has runned before OVMF.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-19-anthony.perard@citrix.com>

OvmfPkg/XenPlatformPei/Platform.h

@@ -89,6 +89,11 @@ XenDetect (
   VOID
   );
 
+BOOLEAN
+XenHvmloaderDetected (
+  VOID
+  );
+
 VOID
 AmdSevInitialize (
   VOID

OvmfPkg/XenPlatformPei/Xen.c

@@ -199,6 +199,13 @@ XenDetect (
   return FALSE;
 }
 
+BOOLEAN
+XenHvmloaderDetected (
+  VOID
+  )
+{
+  return (mXenHvmloaderInfo != NULL);
+}
 
 VOID
 XenPublishRamRegions (