KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code()

Currently has_vhe() detects whether it is being compiled for VHE/NVHE
hyp code based on preprocessor definitions, and uses this knowledge to
avoid redundant runtime checks.

There are other cases where we'd like to use this knowledge, so let's
factor the preprocessor checks out into separate helpers.

There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201026134931.28246-2-mark.rutland@arm.com

arch/arm64/include/asm/virt.h

@@ -83,16 +83,27 @@ static inline bool is_kernel_in_hyp_mode(void)
 	return read_sysreg(CurrentEL) == CurrentEL_EL2;
 }
 
+static __always_inline bool is_vhe_hyp_code(void)
+{
+	/* Only defined for code run in VHE hyp context */
+	return __is_defined(__KVM_VHE_HYPERVISOR__);
+}
+
+static __always_inline bool is_nvhe_hyp_code(void)
+{
+	/* Only defined for code run in NVHE hyp context */
+	return __is_defined(__KVM_NVHE_HYPERVISOR__);
+}
+
 static __always_inline bool has_vhe(void)
 {
 	/*
-	 * The following macros are defined for code specic to VHE/nVHE.
-	 * If has_vhe() is inlined into those compilation units, it can
-	 * be determined statically. Otherwise fall back to caps.
+	 * Code only run in VHE/NVHE hyp context can assume VHE is present or
+	 * absent. Otherwise fall back to caps.
 	 */
-	if (__is_defined(__KVM_VHE_HYPERVISOR__))
+	if (is_vhe_hyp_code())
 		return true;
-	else if (__is_defined(__KVM_NVHE_HYPERVISOR__))
+	else if (is_nvhe_hyp_code())
 		return false;
 	else
 		return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN);