KVM: Delete the now unused kvm_arch_sched_in()

Delete kvm_arch_sched_in() now that all implementations are nops.
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20240522014013.1672962-5-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

arch/arm64/include/asm/kvm_host.h

@@ -1225,7 +1225,6 @@ static inline bool kvm_system_needs_idmapped_vectors(void)
 }
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
 void kvm_arm_init_debug(void);
 void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu);

arch/loongarch/include/asm/kvm_host.h

@@ -261,7 +261,6 @@ static inline bool kvm_is_ifetch_fault(struct kvm_vcpu_arch *arch)
 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, u64 gen) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}

arch/mips/include/asm/kvm_host.h

@@ -890,7 +890,6 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_free_memslot(struct kvm *kvm,
 					 struct kvm_memory_slot *slot) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
 

arch/powerpc/include/asm/kvm_host.h

@@ -897,7 +897,6 @@ struct kvm_vcpu_arch {
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
 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_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
 

arch/riscv/include/asm/kvm_host.h

@@ -286,7 +286,6 @@ struct kvm_vcpu_arch {
 };
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
 #define KVM_RISCV_GSTAGE_TLB_MIN_ORDER		12
 

arch/s390/include/asm/kvm_host.h

@@ -1045,7 +1045,6 @@ extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc);
 extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc);
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-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 *slot) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}

arch/x86/kvm/pmu.c

@@ -521,9 +521,9 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
 	}
 
 	/*
-	 * Unused perf_events are only released if the corresponding MSRs
-	 * weren't accessed during the last vCPU time slice. kvm_arch_sched_in
-	 * triggers KVM_REQ_PMU if cleanup is needed.
+	 * Release unused perf_events if the corresponding guest MSRs weren't
+	 * accessed during the last vCPU time slice (need_cleanup is set when
+	 * the vCPU is scheduled back in).
 	 */
 	if (unlikely(pmu->need_cleanup))
 		kvm_pmu_cleanup(vcpu);

arch/x86/kvm/x86.c

@@ -12575,11 +12575,6 @@ bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
 	return (vcpu->arch.apic_base & MSR_IA32_APICBASE_BSP) != 0;
 }
 
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
-
-}
-
 void kvm_arch_free_vm(struct kvm *kvm)
 {
 #if IS_ENABLED(CONFIG_HYPERV)

include/linux/kvm_host.h

@@ -1495,8 +1495,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 					struct kvm_guest_debug *dbg);
 int kvm_arch_vcpu_ioctl_run(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);
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id);

virt/kvm/kvm_main.c

@@ -6292,7 +6292,6 @@ static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
 	WRITE_ONCE(vcpu->ready, false);
 
 	__this_cpu_write(kvm_running_vcpu, vcpu);
-	kvm_arch_sched_in(vcpu, cpu);
 	kvm_arch_vcpu_load(vcpu, cpu);
 
 	WRITE_ONCE(vcpu->scheduled_out, false);