ArmPkg/ArmLib: Add ArmHasVhe () helper function

Create a helper function to query whether ID_AA64MFR1_EL1 indicates
presence of the Virtualization Host Extensions. This feature is only
visible in AARCH64 state.

Signed-off-by: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Tested-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>

ArmPkg/Include/Library/ArmLib.h

@@ -764,6 +764,24 @@ ArmHasCcidx (
   VOID
   );
 
+#ifdef MDE_CPU_AARCH64
+///
+/// AArch64-only ID Register Helper functions
+///
+
+/**
+  Checks whether the CPU implements the Virtualization Host Extensions.
+
+  @retval TRUE  FEAT_VHE is implemented.
+  @retval FALSE FEAT_VHE is not mplemented.
+**/
+BOOLEAN
+EFIAPI
+ArmHasVhe (
+  VOID
+  );
+#endif // MDE_CPU_AARCH64
+
 #ifdef MDE_CPU_ARM
 ///
 /// AArch32-only ID Register Helper functions