linux-kernel - [PATCH v4 15/17] KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF

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Date:   Thu, 11 Nov 2021 02:07:36 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Will Deacon <will@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Russell King <linux@...linux.org.uk>,
        Marc Zyngier <maz@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Guo Ren <guoren@...nel.org>, Nick Hu <nickhu@...estech.com>,
        Greentime Hu <green.hu@...il.com>,
        Vincent Chen <deanbo422@...il.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>
Cc:     Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        James Morse <james.morse@....com>,
        Alexandru Elisei <alexandru.elisei@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Stefano Stabellini <sstabellini@...nel.org>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
        linux-csky@...r.kernel.org, linux-riscv@...ts.infradead.org,
        kvm@...r.kernel.org, xen-devel@...ts.xenproject.org,
        Artem Kashkanov <artem.kashkanov@...el.com>,
        Like Xu <like.xu.linux@...il.com>,
        Like Xu <like.xu@...ux.intel.com>,
        Zhu Lingshan <lingshan.zhu@...el.com>
Subject: [PATCH v4 15/17] KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF_EVENTS=y

Move the definition of kvm_arm_pmu_available to pmu-emul.c and, out of
"necessity", hide it behind CONFIG_HW_PERF_EVENTS.  Provide a stub for
the key's wrapper, kvm_arm_support_pmu_v3().  Moving the key's definition
out of perf.c will allow a future commit to delete perf.c entirely.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/arm64/kernel/image-vars.h |  2 ++
 arch/arm64/kvm/perf.c          |  2 --
 arch/arm64/kvm/pmu-emul.c      |  2 ++
 include/kvm/arm_pmu.h          | 19 ++++++++++++-------
 4 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index c96a9a0043bf..7eaf1f7c4168 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -102,7 +102,9 @@ KVM_NVHE_ALIAS(__stop___kvm_ex_table);
 KVM_NVHE_ALIAS(kvm_arm_hyp_percpu_base);
 
 /* PMU available static key */
+#ifdef CONFIG_HW_PERF_EVENTS
 KVM_NVHE_ALIAS(kvm_arm_pmu_available);
+#endif
 
 /* Position-independent library routines */
 KVM_NVHE_ALIAS_HYP(clear_page, __pi_clear_page);
diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c
index 374c496a3f1d..52cfab253c65 100644
--- a/arch/arm64/kvm/perf.c
+++ b/arch/arm64/kvm/perf.c
@@ -11,8 +11,6 @@
 
 #include <asm/kvm_emulate.h>
 
-DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
-
 void kvm_perf_init(void)
 {
 	kvm_register_perf_callbacks(NULL);
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index a5e4bbf5e68f..3308ceefa129 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -14,6 +14,8 @@
 #include <kvm/arm_pmu.h>
 #include <kvm/arm_vgic.h>
 
+DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
+
 static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx);
 static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx);
 static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc);
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 90f21898aad8..f9ed4c171d7b 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -13,13 +13,6 @@
 #define ARMV8_PMU_CYCLE_IDX		(ARMV8_PMU_MAX_COUNTERS - 1)
 #define ARMV8_PMU_MAX_COUNTER_PAIRS	((ARMV8_PMU_MAX_COUNTERS + 1) >> 1)
 
-DECLARE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
-
-static __always_inline bool kvm_arm_support_pmu_v3(void)
-{
-	return static_branch_likely(&kvm_arm_pmu_available);
-}
-
 #ifdef CONFIG_HW_PERF_EVENTS
 
 struct kvm_pmc {
@@ -36,6 +29,13 @@ struct kvm_pmu {
 	struct irq_work overflow_work;
 };
 
+DECLARE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
+
+static __always_inline bool kvm_arm_support_pmu_v3(void)
+{
+	return static_branch_likely(&kvm_arm_pmu_available);
+}
+
 #define kvm_arm_pmu_irq_initialized(v)	((v)->arch.pmu.irq_num >= VGIC_NR_SGIS)
 u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
 void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
@@ -65,6 +65,11 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu);
 struct kvm_pmu {
 };
 
+static inline bool kvm_arm_support_pmu_v3(void)
+{
+	return false;
+}
+
 #define kvm_arm_pmu_irq_initialized(v)	(false)
 static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu,
 					    u64 select_idx)
-- 
2.34.0.rc0.344.g81b53c2807-goog