KVM: add kvm_arch_sched_in

Introduce preempt notifiers for architecture specific code.
Advantage over creating a new notifier in every arch is slightly simpler
code and guaranteed call order with respect to kvm_sched_in.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

7 files changed, 24 insertions, 0 deletions

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index a99e0cdf8ba2..9f788ebac55b 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -288,6 +288,10 @@ 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;
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index cd7114147ae7..2362df2a79f9 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -1002,6 +1002,10 @@ 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)
 {
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 4c79284b58be..cbc432f4f0a6 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -720,6 +720,10 @@ 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
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ce81eb2ab76a..a3c324ec4370 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -555,6 +555,10 @@ 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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cd718c01cdf1..7d43dc7bb906 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7171,6 +7171,10 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
                 static_key_slow_dec(&kvm_no_apic_vcpu);
 }
 
+void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
+{
+}
+
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
         if (type)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a4c33b34fe3f..ebd723676633 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -624,6 +624,8 @@ void kvm_arch_exit(void);
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu);
 
+void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);
+
 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 39b16035386f..5a0817ee996e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3124,6 +3124,8 @@ static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
         if (vcpu->preempted)
                 vcpu->preempted = false;
 
+        kvm_arch_sched_in(vcpu, cpu);
+
         kvm_arch_vcpu_load(vcpu, cpu);
 }