From: Sean Christopherson <seanjc@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, Like Xu <like.xu.linux@gmail.com>
Subject: [PATCH v2 2/7] perf/x86/core: Remove unnecessary stubs provided for KVM-only helpers
Date: Wed, 3 Aug 2022 19:26:53 +0000 [thread overview]
Message-ID: <20220803192658.860033-3-seanjc@google.com> (raw)
In-Reply-To: <20220803192658.860033-1-seanjc@google.com>
Remove CONFIG_PERF_EVENT=n stubs for functions that are effectively
KVM-only. KVM selects PERF_EVENT and will never consume the stubs.
Dropping the unnecessary stubs will allow simplifying x86_perf_get_lbr()
by getting rid of the impossible-to-hit error path (which KVM doesn't
even check).
Opportunstically reorganize the declarations to collapse multiple
CONFIG_PERF_EVENTS #ifdefs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/perf_event.h | 53 ++++++++-----------------------
1 file changed, 13 insertions(+), 40 deletions(-)
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index cc47044401ff..aba196172500 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -509,46 +509,18 @@ extern u64 perf_get_hw_event_config(int hw_event);
extern void perf_check_microcode(void);
extern void perf_clear_dirty_counters(void);
extern int x86_perf_rdpmc_index(struct perf_event *event);
-#else
-static inline void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
-{
- memset(cap, 0, sizeof(*cap));
-}
-static inline u64 perf_get_hw_event_config(int hw_event)
-{
- return 0;
-}
-
-static inline void perf_events_lapic_init(void) { }
-static inline void perf_check_microcode(void) { }
-#endif
-
-#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
+#ifdef CONFIG_CPU_SUP_INTEL
extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data);
extern int x86_perf_get_lbr(struct x86_pmu_lbr *lbr);
-#else
-struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data);
-static inline int x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
-{
- return -1;
-}
-#endif
+extern void intel_pt_handle_vmx(int on);
+#endif /* CONFIG_CPU_SUP_INTEL */
-#ifdef CONFIG_CPU_SUP_INTEL
- extern void intel_pt_handle_vmx(int on);
-#else
-static inline void intel_pt_handle_vmx(int on)
-{
+#ifdef CONFIG_CPU_SUP_AMD
+extern void amd_pmu_enable_virt(void);
+extern void amd_pmu_disable_virt(void);
-}
-#endif
-
-#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
- extern void amd_pmu_enable_virt(void);
- extern void amd_pmu_disable_virt(void);
-
-#if defined(CONFIG_PERF_EVENTS_AMD_BRS)
+#ifdef CONFIG_PERF_EVENTS_AMD_BRS
#define PERF_NEEDS_LOPWR_CB 1
@@ -566,12 +538,13 @@ static inline void perf_lopwr_cb(bool lopwr_in)
static_call_mod(perf_lopwr_cb)(lopwr_in);
}
-#endif /* PERF_NEEDS_LOPWR_CB */
+#endif /* CONFIG_PERF_EVENTS_AMD_BRS */
+#endif /* CONFIG_CPU_SUP_AMD */
-#else
- static inline void amd_pmu_enable_virt(void) { }
- static inline void amd_pmu_disable_virt(void) { }
-#endif
+#else /* !CONFIG_PERF_EVENTS */
+static inline void perf_events_lapic_init(void) { }
+static inline void perf_check_microcode(void) { }
+#endif /* CONFIG_PERF_EVENTS */
#define arch_perf_out_copy_user copy_from_user_nmi
--
2.37.1.559.g78731f0fdb-goog
next prev parent reply other threads:[~2022-08-03 19:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-03 19:26 [PATCH v2 0/7] KVM: x86: Intel PERF_CAPABILITIES fixes and cleanups Sean Christopherson
2022-08-03 19:26 ` [PATCH v2 1/7] KVM: x86: Refresh PMU after writes to MSR_IA32_PERF_CAPABILITIES Sean Christopherson
2022-08-03 19:26 ` Sean Christopherson [this message]
2022-08-04 8:49 ` [PATCH v2 2/7] perf/x86/core: Remove unnecessary stubs provided for KVM-only helpers Like Xu
2022-08-04 15:07 ` Sean Christopherson
2022-08-03 19:26 ` [PATCH v2 3/7] perf/x86/core: Drop the unnecessary return value from x86_perf_get_lbr() Sean Christopherson
2022-08-03 19:26 ` [PATCH v2 4/7] KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs Sean Christopherson
2022-08-03 19:26 ` [PATCH v2 5/7] KVM: VMX: Use proper type-safe functions for vCPU => LBRs helpers Sean Christopherson
2022-08-03 19:26 ` [PATCH v2 6/7] KVM: VMX: Adjust number of LBR records for PERF_CAPABILITIES at refresh Sean Christopherson
2022-08-03 19:26 ` [PATCH v2 7/7] KVM: VMX: Simplify capability check when handling PERF_CAPABILITIES write Sean Christopherson
2022-08-04 7:52 ` Like Xu
2022-08-04 15:00 ` Sean Christopherson
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