Use static calls to improve kvm_pmu_ops performance. Introduce the
definitions that will be used by a subsequent patch to actualize the
savings. Add a new kvm-x86-pmu-ops.h header that can be used for the
definition of static calls. This header is also intended to be
used to simplify the defition of amd_pmu_ops and intel_pmu_ops.
Like what we did for kvm_x86_ops, 'pmu_ops' can be covered by
static calls in a simlilar manner for insignificant but not
negligible performance impact, especially on older models.
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
---
arch/x86/include/asm/kvm-x86-pmu-ops.h | 32 ++++++++++++++++++++++++++
arch/x86/kvm/pmu.c | 7 ++++++
arch/x86/kvm/pmu.h | 15 ++++++++++++
3 files changed, 54 insertions(+)
create mode 100644 arch/x86/include/asm/kvm-x86-pmu-ops.h
diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h
new file mode 100644
index 000000000000..b7713b16d21d
--- /dev/null
+++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(KVM_X86_PMU_OP) || !defined(KVM_X86_PMU_OP_NULL)
+BUILD_BUG_ON(1)
+#endif
+
+/*
+ * KVM_X86_PMU_OP() and KVM_X86_PMU_OP_NULL() are used to
+ * help generate "static_call()"s. They are also intended for use when defining
+ * the amd/intel KVM_X86_PMU_OPs. KVM_X86_PMU_OP() can be used
+ * for those functions that follow the [amd|intel]_func_name convention.
+ * KVM_X86_PMU_OP_NULL() can leave a NULL definition for the
+ * case where there is no definition or a function name that
+ * doesn't match the typical naming convention is supplied.
+ */
+KVM_X86_PMU_OP(find_arch_event);
+KVM_X86_PMU_OP(find_fixed_event);
+KVM_X86_PMU_OP(pmc_is_enabled);
+KVM_X86_PMU_OP(pmc_idx_to_pmc);
+KVM_X86_PMU_OP(rdpmc_ecx_to_pmc);
+KVM_X86_PMU_OP(msr_idx_to_pmc);
+KVM_X86_PMU_OP(is_valid_rdpmc_ecx);
+KVM_X86_PMU_OP(is_valid_msr);
+KVM_X86_PMU_OP(get_msr);
+KVM_X86_PMU_OP(set_msr);
+KVM_X86_PMU_OP(refresh);
+KVM_X86_PMU_OP(init);
+KVM_X86_PMU_OP(reset);
+KVM_X86_PMU_OP_NULL(deliver_pmi);
+KVM_X86_PMU_OP_NULL(cleanup);
+
+#undef KVM_X86_PMU_OP
+#undef KVM_X86_PMU_OP_NULL
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 0db1887137d9..b6f08c719125 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -50,6 +50,13 @@
struct kvm_pmu_ops kvm_pmu_ops __read_mostly;
EXPORT_SYMBOL_GPL(kvm_pmu_ops);
+#define KVM_X86_PMU_OP(func) \
+ DEFINE_STATIC_CALL_NULL(kvm_x86_pmu_##func, \
+ *(((struct kvm_pmu_ops *)0)->func))
+#define KVM_X86_PMU_OP_NULL KVM_X86_PMU_OP
+#include <asm/kvm-x86-pmu-ops.h>
+EXPORT_STATIC_CALL_GPL(kvm_x86_pmu_is_valid_msr);
+
static void kvm_pmi_trigger_fn(struct irq_work *irq_work)
{
struct kvm_pmu *pmu = container_of(irq_work, struct kvm_pmu, irq_work);
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index b2fe135d395a..e5550d4acf14 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -3,6 +3,8 @@
#define __KVM_X86_PMU_H
#include <linux/nospec.h>
+#include <linux/static_call_types.h>
+#include <linux/static_call.h>
#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu))
@@ -45,6 +47,19 @@ struct kvm_pmu_ops {
void (*cleanup)(struct kvm_vcpu *vcpu);
};
+#define KVM_X86_PMU_OP(func) \
+ DECLARE_STATIC_CALL(kvm_x86_pmu_##func, *(((struct kvm_pmu_ops *)0)->func))
+#define KVM_X86_PMU_OP_NULL KVM_X86_PMU_OP
+#include <asm/kvm-x86-pmu-ops.h>
+
+static inline void kvm_pmu_ops_static_call_update(void)
+{
+#define KVM_X86_PMU_OP(func) \
+ static_call_update(kvm_x86_pmu_##func, kvm_pmu_ops.func)
+#define KVM_X86_PMU_OP_NULL KVM_X86_PMU_OP
+#include <asm/kvm-x86-pmu-ops.h>
+}
+
static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
--
2.33.0
