[RFC PATCH 20/41] KVM: x86/pmu: Introduce PMU operation prototypes for save/restore PMU context

[Xiong Zhang <xiong.y.zhang@xxxxxxxxxxxxxxx>]

From: Mingwei Zhang <mizhang@xxxxxxxxxx>

Plumb through kvm_pmu_ops with these two extra functions to allow pmu
context switch.

Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
 arch/x86/include/asm/kvm-x86-pmu-ops.h |  2 ++
 arch/x86/kvm/pmu.c                     | 14 ++++++++++++++
 arch/x86/kvm/pmu.h                     |  4 ++++
 3 files changed, 20 insertions(+)

diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h
index a2acf0afee5d..ee201ac95f57 100644
--- a/arch/x86/include/asm/kvm-x86-pmu-ops.h
+++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h
@@ -26,6 +26,8 @@ KVM_X86_PMU_OP(reset)
 KVM_X86_PMU_OP_OPTIONAL(deliver_pmi)
 KVM_X86_PMU_OP_OPTIONAL(cleanup)
 KVM_X86_PMU_OP_OPTIONAL(passthrough_pmu_msrs)
+KVM_X86_PMU_OP_OPTIONAL(save_pmu_context)
+KVM_X86_PMU_OP_OPTIONAL(restore_pmu_context)
 
 #undef KVM_X86_PMU_OP
 #undef KVM_X86_PMU_OP_OPTIONAL
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index d83746f93392..9d737f5b96bf 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -898,3 +898,17 @@ void kvm_pmu_passthrough_pmu_msrs(struct kvm_vcpu *vcpu)
 {
 	static_call_cond(kvm_x86_pmu_passthrough_pmu_msrs)(vcpu);
 }
+
+void kvm_pmu_save_pmu_context(struct kvm_vcpu *vcpu)
+{
+	lockdep_assert_irqs_disabled();
+
+	static_call_cond(kvm_x86_pmu_save_pmu_context)(vcpu);
+}
+
+void kvm_pmu_restore_pmu_context(struct kvm_vcpu *vcpu)
+{
+	lockdep_assert_irqs_disabled();
+
+	static_call_cond(kvm_x86_pmu_restore_pmu_context)(vcpu);
+}
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index d575808c7258..a4c0b2e2c24b 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -34,6 +34,8 @@ struct kvm_pmu_ops {
 	void (*deliver_pmi)(struct kvm_vcpu *vcpu);
 	void (*cleanup)(struct kvm_vcpu *vcpu);
 	void (*passthrough_pmu_msrs)(struct kvm_vcpu *vcpu);
+	void (*save_pmu_context)(struct kvm_vcpu *vcpu);
+	void (*restore_pmu_context)(struct kvm_vcpu *vcpu);
 
 	const u64 EVENTSEL_EVENT;
 	const int MAX_NR_GP_COUNTERS;
@@ -288,6 +290,8 @@ void kvm_pmu_destroy(struct kvm_vcpu *vcpu);
 int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp);
 void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id);
 void kvm_pmu_passthrough_pmu_msrs(struct kvm_vcpu *vcpu);
+void kvm_pmu_save_pmu_context(struct kvm_vcpu *vcpu);
+void kvm_pmu_restore_pmu_context(struct kvm_vcpu *vcpu);
 
 bool is_vmware_backdoor_pmc(u32 pmc_idx);
 
-- 
2.34.1