[PATCH v6 14/44] KVM: Add a simplified wrapper for registering perf callbacks

[Sean Christopherson <seanjc@google.com>]

Add a parameter-less API for registering perf callbacks in anticipation of
introducing another x86-only parameter for handling mediated PMU PMIs.

No functional change intended.

Acked-by: Anup Patel <anup@brainfault.org>
Tested-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/arm64/kvm/arm.c      |  2 +-
 arch/loongarch/kvm/main.c |  2 +-
 arch/riscv/kvm/main.c     |  2 +-
 arch/x86/kvm/x86.c        |  2 +-
 include/linux/kvm_host.h  | 11 +++++++++--
 virt/kvm/kvm_main.c       |  5 +++--
 6 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 97627638e802..153166ca626a 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2357,7 +2357,7 @@ static int __init init_subsystems(void)
 	if (err)
 		goto out;
 
-	kvm_register_perf_callbacks(NULL);
+	kvm_register_perf_callbacks();
 
 out:
 	if (err)
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 80ea63d465b8..f62326fe29fa 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -394,7 +394,7 @@ static int kvm_loongarch_env_init(void)
 	}
 
 	kvm_init_gcsr_flag();
-	kvm_register_perf_callbacks(NULL);
+	kvm_register_perf_callbacks();
 
 	/* Register LoongArch IPI interrupt controller interface. */
 	ret = kvm_loongarch_register_ipi_device();
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index 45536af521f0..0f3fe3986fc0 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -174,7 +174,7 @@ static int __init riscv_kvm_init(void)
 
 	kvm_riscv_setup_vendor_features();
 
-	kvm_register_perf_callbacks(NULL);
+	kvm_register_perf_callbacks();
 
 	rc = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 	if (rc) {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0c6d899d53dd..1b2827cecf38 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10107,7 +10107,7 @@ int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
 		set_hv_tscchange_cb(kvm_hyperv_tsc_notifier);
 #endif
 
-	kvm_register_perf_callbacks(ops->handle_intel_pt_intr);
+	__kvm_register_perf_callbacks(ops->handle_intel_pt_intr, NULL);
 
 	if (IS_ENABLED(CONFIG_KVM_SW_PROTECTED_VM) && tdp_mmu_enabled)
 		kvm_caps.supported_vm_types |= BIT(KVM_X86_SW_PROTECTED_VM);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d93f75b05ae2..8e410d1a63df 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1749,10 +1749,17 @@ static inline bool kvm_arch_intc_initialized(struct kvm *kvm)
 #ifdef CONFIG_GUEST_PERF_EVENTS
 unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu);
 
-void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void));
+void __kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void),
+				   void (*mediated_pmi_handler)(void));
+
+static inline void kvm_register_perf_callbacks(void)
+{
+	__kvm_register_perf_callbacks(NULL, NULL);
+}
+
 void kvm_unregister_perf_callbacks(void);
 #else
-static inline void kvm_register_perf_callbacks(void *ign) {}
+static inline void kvm_register_perf_callbacks(void) {}
 static inline void kvm_unregister_perf_callbacks(void) {}
 #endif /* CONFIG_GUEST_PERF_EVENTS */
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4954cbbb05e8..16b24da9cda5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -6474,10 +6474,11 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = {
 	.handle_mediated_pmi	= NULL,
 };
 
-void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void))
+void __kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void),
+				   void (*mediated_pmi_handler)(void))
 {
 	kvm_guest_cbs.handle_intel_pt_intr = pt_intr_handler;
-	kvm_guest_cbs.handle_mediated_pmi = NULL;
+	kvm_guest_cbs.handle_mediated_pmi = mediated_pmi_handler;
 
 	perf_register_guest_info_callbacks(&kvm_guest_cbs);
 }
-- 
2.52.0.223.gf5cc29aaa4-goog