KVM: PPC: Implement kvm_arch_intc_initialized() for PPC

It doesn't make sense to create irqfds for a VM that doesn't have
in-kernel interrupt controller emulation.  There is an existing
interface for architecture code to tell the irqfd code whether or
not any interrupt controller has been initialized, called
kvm_arch_intc_initialized(), so let's implement that for powerpc.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
(cherry picked from commit 34a75b0)
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/include/asm/kvm_host.h

@@ -43,6 +43,8 @@
 #include <asm/cputhreads.h>
 #define KVM_MAX_VCPU_ID                (threads_per_subcore * KVM_MAX_VCORES)
 
+#define __KVM_HAVE_ARCH_INTC_INITIALIZED
+
 #ifdef CONFIG_KVM_MMIO
 #define KVM_COALESCED_MMIO_PAGE_OFFSET 1
 #endif

arch/powerpc/kvm/powerpc.c

@@ -1201,6 +1201,19 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 	return r;
 }
 
+bool kvm_arch_intc_initialized(struct kvm *kvm)
+{
+#ifdef CONFIG_KVM_MPIC
+	if (kvm->arch.mpic)
+		return true;
+#endif
+#ifdef CONFIG_KVM_XICS
+	if (kvm->arch.xics)
+		return true;
+#endif
+	return false;
+}
+
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                     struct kvm_mp_state *mp_state)
 {