KVM: remove kvm_arch_has_vcpu_debugfs()

There is no need for this function as all arches have to implement
kvm_arch_create_vcpu_debugfs() no matter what.  A #define symbol
let us actually simplify the code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/mips/kvm/mips.c

@@ -150,16 +150,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	return 0;
 }
 
-bool kvm_arch_has_vcpu_debugfs(void)
-{
-	return false;
-}
-
-int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
-{
-	return 0;
-}
-
 void kvm_mips_free_vcpus(struct kvm *kvm)
 {
 	unsigned int i;

arch/powerpc/kvm/powerpc.c

@@ -457,16 +457,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	return -EINVAL;
 }
 
-bool kvm_arch_has_vcpu_debugfs(void)
-{
-	return false;
-}
-
-int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
-{
-	return 0;
-}
-
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	unsigned int i;

arch/s390/kvm/kvm-s390.c

@@ -2516,16 +2516,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	return rc;
 }
 
-bool kvm_arch_has_vcpu_debugfs(void)
-{
-	return false;
-}
-
-int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
-{
-	return 0;
-}
-
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
 	VCPU_EVENT(vcpu, 3, "%s", "free cpu");

arch/x86/include/asm/kvm_host.h

@@ -35,6 +35,8 @@
 #include <asm/kvm_vcpu_regs.h>
 #include <asm/hyperv-tlfs.h>
 
+#define __KVM_HAVE_ARCH_VCPU_DEBUGFS
+
 #define KVM_MAX_VCPUS 288
 #define KVM_SOFT_MAX_VCPUS 240
 #define KVM_MAX_VCPU_ID 1023

arch/x86/kvm/debugfs.c

@@ -8,11 +8,6 @@
 #include <linux/debugfs.h>
 #include "lapic.h"
 
-bool kvm_arch_has_vcpu_debugfs(void)
-{
-	return true;
-}
-
 static int vcpu_get_timer_advance_ns(void *data, u64 *val)
 {
 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;

include/linux/kvm_host.h

@@ -861,8 +861,9 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);
 
-bool kvm_arch_has_vcpu_debugfs(void);
+#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
 int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu);
+#endif
 
 int kvm_arch_hardware_enable(void);
 void kvm_arch_hardware_disable(void);

virt/kvm/arm/arm.c

@@ -144,11 +144,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	return ret;
 }
 
-bool kvm_arch_has_vcpu_debugfs(void)
-{
-	return false;
-}
-
 int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
 {
 	return 0;

virt/kvm/kvm_main.c

@@ -2617,12 +2617,10 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu)
 
 static int kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
 {
+#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
 	char dir_name[ITOA_MAX_LEN * 2];
 	int ret;
 
-	if (!kvm_arch_has_vcpu_debugfs())
-		return 0;
-
 	if (!debugfs_initialized())
 		return 0;
 
@@ -2637,6 +2635,7 @@ static int kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
 		debugfs_remove_recursive(vcpu->debugfs_dentry);
 		return ret;
 	}
+#endif
 
 	return 0;
 }