arm64: KVM: Add access handler for PMCR register

Add reset handler which gets host value of PMCR_EL0 and make writable
bits architecturally UNKNOWN except PMCR.E which is zero. Add an access
handler for PMCR.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

include/kvm/arm_pmu.h

@@ -34,9 +34,13 @@ struct kvm_pmu {
 	struct kvm_pmc pmc[ARMV8_PMU_MAX_COUNTERS];
 	bool ready;
 };
+
+#define kvm_arm_pmu_v3_ready(v)		((v)->arch.pmu.ready)
 #else
 struct kvm_pmu {
 };
+
+#define kvm_arm_pmu_v3_ready(v)		(false)
 #endif
 
 #endif