KVM: static inline empty kvm_arch functions

Using static inline is going to save few bytes and cycles.
For example on powerpc, the difference is 700 B after stripping.
(5 kB before)

This patch also deals with two overlooked empty functions:
kvm_arch_flush_shadow was not removed from arch/mips/kvm/mips.c
  2df72e9b KVM: split kvm_arch_flush_shadow
and kvm_arch_sched_in never made it into arch/ia64/kvm/kvm-ia64.c.
  e790d9ef KVM: add kvm_arch_sched_in
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/arm/include/asm/kvm_host.h

@@ -230,4 +230,10 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic)
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 
+static inline void kvm_arch_hardware_disable(void *garbage) {}
+static inline void kvm_arch_hardware_unsetup(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+
 #endif /* __ARM_KVM_HOST_H__ */

arch/arm/kvm/arm.c

@@ -97,27 +97,16 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
-void kvm_arch_hardware_disable(void *garbage)
-{
-}
-
 int kvm_arch_hardware_setup(void)
 {
 	return 0;
 }
 
-void kvm_arch_hardware_unsetup(void)
-{
-}
-
 void kvm_arch_check_processor_compat(void *rtn)
 {
 	*(int *)rtn = 0;
 }
 
-void kvm_arch_sync_events(struct kvm *kvm)
-{
-}
 
 /**
  * kvm_arch_init_vm - initializes a VM data structure
@@ -284,14 +273,6 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
-{
-}
-
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
-}
-
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	vcpu->cpu = cpu;

arch/arm64/include/asm/kvm_host.h

@@ -242,4 +242,10 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic)
 	}
 }
 
+static inline void kvm_arch_hardware_disable(void *garbage) {}
+static inline void kvm_arch_hardware_unsetup(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+
 #endif /* __ARM64_KVM_HOST_H__ */

arch/ia64/include/asm/kvm_host.h

@@ -592,6 +592,18 @@ void kvm_sal_emul(struct kvm_vcpu *vcpu);
 struct kvm *kvm_arch_alloc_vm(void);
 void kvm_arch_free_vm(struct kvm *kvm);
 
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_free_memslot(struct kvm *kvm,
+		struct kvm_memory_slot *free, struct kvm_memory_slot *dont) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm) {}
+static inline void kvm_arch_commit_memory_region(struct kvm *kvm,
+		struct kvm_userspace_memory_region *mem,
+		const struct kvm_memory_slot *old,
+		enum kvm_mr_change change) {}
+static inline void kvm_arch_hardware_unsetup(void) {}
+
 #endif /* __ASSEMBLY__*/
 
 #endif

arch/ia64/kvm/kvm-ia64.c

@@ -1364,10 +1364,6 @@ static void kvm_release_vm_pages(struct kvm *kvm)
 	}
 }
 
-void kvm_arch_sync_events(struct kvm *kvm)
-{
-}
-
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_iommu_unmap_guest(kvm);
@@ -1376,10 +1372,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_release_vm_pages(kvm);
 }
 
-void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
-{
-}
-
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	if (cpu != vcpu->cpu) {
@@ -1468,7 +1460,6 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 	kfree(vcpu->arch.apic);
 }
 
-
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {
@@ -1551,21 +1542,12 @@ int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont)
-{
-}
-
 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    unsigned long npages)
 {
 	return 0;
 }
 
-void kvm_arch_memslots_updated(struct kvm *kvm)
-{
-}
-
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 		struct kvm_memory_slot *memslot,
 		struct kvm_userspace_memory_region *mem,
@@ -1597,14 +1579,6 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
 	return 0;
 }
 
-void kvm_arch_commit_memory_region(struct kvm *kvm,
-		struct kvm_userspace_memory_region *mem,
-		const struct kvm_memory_slot *old,
-		enum kvm_mr_change change)
-{
-	return;
-}
-
 void kvm_arch_flush_shadow_all(struct kvm *kvm)
 {
 	kvm_flush_remote_tlbs(kvm);
@@ -1853,10 +1827,6 @@ int kvm_arch_hardware_setup(void)
 	return 0;
 }
 
-void kvm_arch_hardware_unsetup(void)
-{
-}
-
 int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq)
 {
 	return __apic_accept_irq(vcpu, irq->vector);

arch/mips/include/asm/kvm_host.h

@@ -762,5 +762,16 @@ extern int kvm_mips_trans_mtc0(uint32_t inst, uint32_t *opc,
 extern void kvm_mips_dump_stats(struct kvm_vcpu *vcpu);
 extern unsigned long kvm_mips_get_ramsize(struct kvm *kvm);
 
+static inline void kvm_arch_hardware_disable(void *garbage) {}
+static inline void kvm_arch_hardware_unsetup(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_free_memslot(struct kvm *kvm,
+		struct kvm_memory_slot *free, struct kvm_memory_slot *dont) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm) {}
+static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
+static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
+		struct kvm_memory_slot *slot) {}
+static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
 #endif /* __MIPS_KVM_HOST_H__ */

arch/mips/kvm/mips.c

@@ -82,19 +82,11 @@ int kvm_arch_hardware_enable(void *garbage)
 	return 0;
 }
 
-void kvm_arch_hardware_disable(void *garbage)
-{
-}
-
 int kvm_arch_hardware_setup(void)
 {
 	return 0;
 }
 
-void kvm_arch_hardware_unsetup(void)
-{
-}
-
 void kvm_arch_check_processor_compat(void *rtn)
 {
 	*(int *)rtn = 0;
@@ -163,10 +155,6 @@ void kvm_mips_free_vcpus(struct kvm *kvm)
 	mutex_unlock(&kvm->lock);
 }
 
-void kvm_arch_sync_events(struct kvm *kvm)
-{
-}
-
 static void kvm_mips_uninit_tlbs(void *arg)
 {
 	/* Restore wired count */
@@ -194,21 +182,12 @@ long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
 	return -ENOIOCTLCMD;
 }
 
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont)
-{
-}
-
 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    unsigned long npages)
 {
 	return 0;
 }
 
-void kvm_arch_memslots_updated(struct kvm *kvm)
-{
-}
-
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				   struct kvm_memory_slot *memslot,
 				   struct kvm_userspace_memory_region *mem,
@@ -254,19 +233,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 	}
 }
 
-void kvm_arch_flush_shadow_all(struct kvm *kvm)
-{
-}
-
-void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
-				   struct kvm_memory_slot *slot)
-{
-}
-
-void kvm_arch_flush_shadow(struct kvm *kvm)
-{
-}
-
 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 {
 	int err, size, offset;
@@ -998,14 +964,6 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
-{
-}
-
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
-}
-
 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 				  struct kvm_translation *tr)
 {

arch/powerpc/include/asm/kvm_host.h

@@ -682,4 +682,12 @@ struct kvm_vcpu_arch {
 #define __KVM_HAVE_ARCH_WQP
 #define __KVM_HAVE_CREATE_DEVICE
 
+static inline void kvm_arch_hardware_disable(void *garbage) {}
+static inline void kvm_arch_hardware_unsetup(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm) {}
+static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_exit(void) {}
+
 #endif /* __POWERPC_KVM_HOST_H__ */

arch/powerpc/kvm/powerpc.c

@@ -389,19 +389,11 @@ int kvm_arch_hardware_enable(void *garbage)
 	return 0;
 }
 
-void kvm_arch_hardware_disable(void *garbage)
-{
-}
-
 int kvm_arch_hardware_setup(void)
 {
 	return 0;
 }
 
-void kvm_arch_hardware_unsetup(void)
-{
-}
-
 void kvm_arch_check_processor_compat(void *rtn)
 {
 	*(int *)rtn = kvmppc_core_check_processor_compat();
@@ -462,10 +454,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	module_put(kvm->arch.kvm_ops->owner);
 }
 
-void kvm_arch_sync_events(struct kvm *kvm)
-{
-}
-
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r;
@@ -608,10 +596,6 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 	return kvmppc_core_create_memslot(kvm, slot, npages);
 }
 
-void kvm_arch_memslots_updated(struct kvm *kvm)
-{
-}
-
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				   struct kvm_memory_slot *memslot,
 				   struct kvm_userspace_memory_region *mem,
@@ -628,10 +612,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 	kvmppc_core_commit_memory_region(kvm, mem, old);
 }
 
-void kvm_arch_flush_shadow_all(struct kvm *kvm)
-{
-}
-
 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 				   struct kvm_memory_slot *slot)
 {
@@ -720,10 +700,6 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 	kvmppc_subarch_vcpu_uninit(vcpu);
 }
 
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
-}
-
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 #ifdef CONFIG_BOOKE
@@ -1347,9 +1323,4 @@ int kvm_arch_init(void *opaque)
 	return 0;
 }
 
-void kvm_arch_exit(void)
-{
-
-}
-
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ppc_instr);

arch/s390/include/asm/kvm_host.h

@@ -451,4 +451,18 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
 
 extern int sie64a(struct kvm_s390_sie_block *, u64 *);
 extern char sie_exit;
+
+static inline void kvm_arch_hardware_disable(void *garbage) {}
+static inline void kvm_arch_check_processor_compat(void *rtn) {}
+static inline void kvm_arch_exit(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_free_memslot(struct kvm *kvm,
+		struct kvm_memory_slot *free, struct kvm_memory_slot *dont) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm) {}
+static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
+static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
+		struct kvm_memory_slot *slot) {}
+
 #endif

arch/s390/kvm/kvm-s390.c

@@ -106,10 +106,6 @@ int kvm_arch_hardware_enable(void *garbage)
 	return 0;
 }
 
-void kvm_arch_hardware_disable(void *garbage)
-{
-}
-
 static void kvm_gmap_notifier(struct gmap *gmap, unsigned long address);
 
 int kvm_arch_hardware_setup(void)
@@ -124,19 +120,11 @@ void kvm_arch_hardware_unsetup(void)
 	gmap_unregister_ipte_notifier(&gmap_notifier);
 }
 
-void kvm_arch_check_processor_compat(void *rtn)
-{
-}
-
 int kvm_arch_init(void *opaque)
 {
 	return 0;
 }
 
-void kvm_arch_exit(void)
-{
-}
-
 /* Section: device related */
 long kvm_arch_dev_ioctl(struct file *filp,
 			unsigned int ioctl, unsigned long arg)
@@ -514,10 +502,6 @@ static void kvm_free_vcpus(struct kvm *kvm)
 	mutex_unlock(&kvm->lock);
 }
 
-void kvm_arch_sync_events(struct kvm *kvm)
-{
-}
-
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_free_vcpus(kvm);
@@ -552,15 +536,6 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
-{
-	/* Nothing todo */
-}
-
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
-}
-
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	save_fp_ctl(&vcpu->arch.host_fpregs.fpc);
@@ -1708,21 +1683,12 @@ int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont)
-{
-}
-
 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    unsigned long npages)
 {
 	return 0;
 }
 
-void kvm_arch_memslots_updated(struct kvm *kvm)
-{
-}
-
 /* Section: memory related */
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				   struct kvm_memory_slot *memslot,
@@ -1768,15 +1734,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 	return;
 }
 
-void kvm_arch_flush_shadow_all(struct kvm *kvm)
-{
-}
-
-void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
-				   struct kvm_memory_slot *slot)
-{
-}
-
 static int __init kvm_s390_init(void)
 {
 	int ret;