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From: Like Xu <like.xu.linux@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>, Jim Mattson <jmattson@google.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Like Xu <likexu@tencent.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 08/11] perf: x86/core: Add interface to query perfmon_event_map[] directly
Date: Mon, 21 Feb 2022 19:51:58 +0800	[thread overview]
Message-ID: <20220221115201.22208-9-likexu@tencent.com> (raw)
In-Reply-To: <20220221115201.22208-1-likexu@tencent.com>

From: Like Xu <likexu@tencent.com>

Currently, we have [intel|knc|p4|p6]_perfmon_event_map on the Intel
platforms and amd_[f17h]_perfmon_event_map on the AMD platforms.

Early clumsy KVM code or other potential perf_event users may have
hard-coded these perfmon_maps (e.g., arch/x86/kvm/svm/pmu.c), so
it would not make sense to program a common hardware event based
on the generic "enum perf_hw_id" once the two tables do not match.

Just provide an interface for callers outside the perf subsystem to get
the counter config based on the perfmon_event_map currently in use,
and it also helps to save bytes.

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Like Xu <likexu@tencent.com>
---
 arch/x86/events/core.c            | 11 +++++++++++
 arch/x86/include/asm/perf_event.h |  6 ++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index e686c5e0537b..e760a1348c62 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2996,3 +2996,14 @@ void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
 	cap->events_mask_len	= x86_pmu.events_mask_len;
 }
 EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);
+
+u64 perf_get_hw_event_config(int hw_event)
+{
+	int max = x86_pmu.max_events;
+
+	if (hw_event < max)
+		return x86_pmu.event_map(array_index_nospec(hw_event, max));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(perf_get_hw_event_config);
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 8fc1b5003713..822927045406 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -477,6 +477,7 @@ struct x86_pmu_lbr {
 };
 
 extern void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap);
+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);
@@ -486,6 +487,11 @@ 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
-- 
2.35.0


  parent reply	other threads:[~2022-02-21 11:53 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-21 11:51 [PATCH 00/11] KVM: x86/pmu: Get rid of PERF_TYPE_HARDWAR and other minor fixes Like Xu
2022-02-21 11:51 ` [PATCH 01/11] KVM: x86/pmu: Update comments for AMD gp counters Like Xu
2022-02-23 19:50   ` Jim Mattson
2022-02-21 11:51 ` [PATCH 02/11] KVM: x86/pmu: Extract check_pmu_event_filter() from the same semantics Like Xu
2022-02-21 11:51 ` [PATCH 03/11] KVM: x86/pmu: Pass only "struct kvm_pmc *pmc" to reprogram_counter() Like Xu
2022-02-21 11:51 ` [PATCH 04/11] KVM: x86/pmu: Drop "u64 eventsel" for reprogram_gp_counter() Like Xu
2022-02-21 11:51 ` [PATCH 05/11] KVM: x86/pmu: Drop "u8 ctrl, int idx" for reprogram_fixed_counter() Like Xu
2022-02-21 11:51 ` [PATCH 06/11] KVM: x86/pmu: Use only the uniformly exported interface reprogram_counter() Like Xu
2022-02-21 11:51 ` [PATCH 07/11] KVM: x86/pmu: Use PERF_TYPE_RAW to merge reprogram_{gp, fixed}counter() Like Xu
2022-02-21 11:51 ` Like Xu [this message]
2022-02-21 11:51 ` [PATCH 09/11] KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config() Like Xu
2022-02-21 20:57   ` kernel test robot
2022-02-21 11:52 ` [PATCH 10/11] KVM: x86/pmu: Drop amd_event_mapping[] in the KVM context Like Xu
2022-02-21 11:52 ` [PATCH 11/11] KVM: x86/pmu: Protect kvm->arch.pmu_event_filter with SRCU Like Xu

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