KVM: arm64: Add is_pkvm_initialized() helper

Add a helper allowing to check when the pkvm static key is enabled to
ease the introduction of pkvm hooks in other parts of the code.

Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-18-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Quentin Perret

arch/arm64/include/asm/virt.h

@@ -82,15 +82,20 @@ bool is_kvm_arm_initialised(void);
 
 DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
 
+static inline bool is_pkvm_initialized(void)
+{
+	return IS_ENABLED(CONFIG_KVM) &&
+	       static_branch_likely(&kvm_protected_mode_initialized);
+}
+
 /* Reports the availability of HYP mode */
 static inline bool is_hyp_mode_available(void)
 {
 	/*
 	 * If KVM protected mode is initialized, all CPUs must have been booted
 	 * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
 	 */
-	if (IS_ENABLED(CONFIG_KVM) &&
-	    static_branch_likely(&kvm_protected_mode_initialized))
+	if (is_pkvm_initialized())
 		return true;
 
 	return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
@@ -104,8 +109,7 @@ static inline bool is_hyp_mode_mismatched(void)
 	 * If KVM protected mode is initialized, all CPUs must have been booted
 	 * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
 	 */
-	if (IS_ENABLED(CONFIG_KVM) &&
-	    static_branch_likely(&kvm_protected_mode_initialized))
+	if (is_pkvm_initialized())
 		return false;
 
 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];