[PATCH v4 15/17] KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF_EVENTS=y

From: Sean Christopherson
Date: Wed Nov 10 2021 - 21:09:27 EST


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@xxxxxxxxxx>
---
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