[PATCH v2 5/5] KVM: X86: Save/restore residency values when vCPU migrations

[Wanpeng Li]

From: Wanpeng Li <wanpengli@xxxxxxxxxxx>

To save/restore residency values when vCPU migrates between mulitple 
pCPUs.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
 arch/arm/include/asm/kvm_host.h     |  1 +
 arch/arm64/include/asm/kvm_host.h   |  1 +
 arch/mips/include/asm/kvm_host.h    |  1 +
 arch/powerpc/include/asm/kvm_host.h |  1 +
 arch/s390/include/asm/kvm_host.h    |  1 +
 arch/x86/kvm/x86.c                  | 38 +++++++++++++++++++++++++++++++++++++
 include/linux/kvm_host.h            |  1 +
 virt/kvm/kvm_main.c                 |  1 +
 8 files changed, 45 insertions(+)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 075e192..5e6a487 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -346,6 +346,7 @@ 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) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
 
 static inline void kvm_arm_init_debug(void) {}
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4bcd9c1..12fec7d 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -557,6 +557,7 @@ void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu);
 static inline void kvm_arch_hardware_unsetup(void) {}
 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_sched_out(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
 
 void kvm_arm_init_debug(void);
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 41204a4..217bbfd 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -1136,6 +1136,7 @@ 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, u64 gen) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 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) {}
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index d10df67..4f5306d 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -854,6 +854,7 @@ 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_sched_out(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_exit(void) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index da5825a..8710298 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -908,6 +908,7 @@ static inline void kvm_arch_hardware_disable(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_sched_out(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, u64 gen) {}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 36905cd..de91cc5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3332,6 +3332,36 @@ void kvm_core_residency_setup(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvm_core_residency_setup);
 
+static void kvm_residency_sched_out(struct kvm_vcpu *vcpu)
+{
+	int i;
+	struct kvm_residency_msr *msr;
+
+	for (i = 0; i < NR_CORE_RESIDENCY_MSRS; i++) {
+		msr = &vcpu->arch.core_cstate_msrs[i];
+		if (msr->count_with_host) {
+			WARN_ON(!msr->delta_from_host);
+			msr->value += kvm_residency_read_host(vcpu, msr);
+			msr->delta_from_host = false;
+		}
+	}
+}
+
+static void kvm_residency_sched_in(struct kvm_vcpu *vcpu)
+{
+	int i;
+	struct kvm_residency_msr *msr;
+
+	for (i = 0; i < NR_CORE_RESIDENCY_MSRS; i++) {
+		msr = &vcpu->arch.core_cstate_msrs[i];
+		if (msr->count_with_host) {
+			WARN_ON(msr->delta_from_host);
+			msr->value -= kvm_residency_read_host(vcpu, msr);
+			msr->delta_from_host = true;
+		}
+	}
+}
+
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	/* Address WBINVD may be executed by guest */
@@ -9276,6 +9306,14 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
 {
 	vcpu->arch.l1tf_flush_l1d = true;
 	kvm_x86_ops->sched_in(vcpu, cpu);
+	if (kvm_mwait_in_guest(vcpu->kvm))
+		kvm_residency_sched_in(vcpu);
+}
+
+void kvm_arch_sched_out(struct kvm_vcpu *vcpu)
+{
+	if (kvm_mwait_in_guest(vcpu->kvm))
+		kvm_residency_sched_out(vcpu);
 }
 
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index abafddb..288bd34 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -854,6 +854,7 @@ 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_sched_out(struct kvm_vcpu *vcpu);
 
 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9613987..7d504c0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4221,6 +4221,7 @@ static void kvm_sched_out(struct preempt_notifier *pn,
 
 	if (current->state == TASK_RUNNING)
 		vcpu->preempted = true;
+	kvm_arch_sched_out(vcpu);
 	kvm_arch_vcpu_put(vcpu);
 }
 
-- 
2.7.4