From: Wei Wang <wei.w.wang@intel.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
pbonzini@redhat.com, ak@linux.intel.com
Cc: kan.liang@intel.com, peterz@infradead.org, mingo@redhat.com,
rkrcmar@redhat.com, like.xu@intel.com, wei.w.wang@intel.com
Subject: [PATCH v2 1/8] perf/x86: add a function to get the lbr stack
Date: Thu, 6 Sep 2018 19:30:49 +0800 [thread overview]
Message-ID: <1536233456-12173-2-git-send-email-wei.w.wang@intel.com> (raw)
In-Reply-To: <1536233456-12173-1-git-send-email-wei.w.wang@intel.com>
The LBR stack MSRs are architecturally specific. The perf subsystem has
already assigned the abstracted MSR values based on the CPU architecture.
This patch enables a caller outside the perf subsystem to get the LBR
stack info. This is useful for hyperviosrs to prepare the lbr feature
for the guest.
Signed-off-by: Like Xu <like.xu@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
---
arch/x86/events/intel/lbr.c | 23 +++++++++++++++++++++++
arch/x86/include/asm/perf_event.h | 14 ++++++++++++++
2 files changed, 37 insertions(+)
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index f3e006b..7c3958e 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -1273,3 +1273,26 @@ void intel_pmu_lbr_init_knl(void)
x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
x86_pmu.lbr_sel_map = snb_lbr_sel_map;
}
+
+/**
+ * perf_get_lbr_stack - get the lbr stack related MSRs
+ *
+ * @stack: the caller's memory to get the lbr stack
+ *
+ * Returns: 0 indicates that the lbr stack has been successfully obtained.
+ */
+int perf_get_lbr_stack(struct perf_lbr_stack *stack)
+{
+ stack->lbr_nr = x86_pmu.lbr_nr;
+ stack->lbr_tos = x86_pmu.lbr_tos;
+ stack->lbr_from = x86_pmu.lbr_from;
+ stack->lbr_to = x86_pmu.lbr_to;
+
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
+ stack->lbr_info = MSR_LBR_INFO_0;
+ else
+ stack->lbr_info = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(perf_get_lbr_stack);
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 12f5408..f40e80a 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -267,7 +267,16 @@ struct perf_guest_switch_msr {
u64 host, guest;
};
+struct perf_lbr_stack {
+ int lbr_nr;
+ unsigned long lbr_tos;
+ unsigned long lbr_from;
+ unsigned long lbr_to;
+ unsigned long lbr_info;
+};
+
extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr);
+extern int perf_get_lbr_stack(struct perf_lbr_stack *stack);
extern void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap);
extern void perf_check_microcode(void);
#else
@@ -277,6 +286,11 @@ static inline struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
return NULL;
}
+static inline int perf_get_lbr_stack(struct perf_lbr_stack *stack)
+{
+ return -1;
+}
+
static inline void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
{
memset(cap, 0, sizeof(*cap));
--
2.7.4
next prev parent reply other threads:[~2018-09-06 12:01 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-06 11:30 [PATCH v2 0/8] Guest LBR Enabling Wei Wang
2018-09-06 11:30 ` Wei Wang [this message]
2018-09-07 3:28 ` [PATCH v2 1/8] perf/x86: add a function to get the lbr stack Andi Kleen
2018-09-07 6:45 ` Wei Wang
2018-09-06 11:30 ` [PATCH v2 2/8] KVM/x86: KVM_CAP_X86_GUEST_LBR Wei Wang
2018-09-06 11:30 ` [PATCH v2 3/8] KVM/vmx: Pass through the lbr stack to a guest Wei Wang
2018-09-06 11:30 ` [PATCH v2 4/8] KVM/x86: expose MSR_IA32_PERF_CAPABILITIES to the guest Wei Wang
2018-09-06 11:30 ` [PATCH v2 5/8] KVM/x86: enable the guest to access the debugctl msr Wei Wang
2018-09-06 11:30 ` [PATCH v2 6/8] perf/x86/intel/lbr: guest requesting KVM for lbr stack save/restore Wei Wang
2018-09-07 3:27 ` Andi Kleen
2018-09-07 5:24 ` Wei Wang
2018-09-07 14:10 ` Andi Kleen
2018-09-07 15:20 ` Wang, Wei W
2018-09-07 20:05 ` Andi Kleen
2018-09-08 1:34 ` Wang, Wei W
2018-09-06 11:30 ` [PATCH v2 7/8] KVM: PMU: support to save/restore the guest lbr stack on vCPU switching Wei Wang
2018-09-07 14:36 ` Jann Horn
2018-09-07 15:21 ` Wang, Wei W
2018-09-18 0:58 ` Gonglei (Arei)
2018-09-18 2:56 ` Andi Kleen
2018-09-18 9:57 ` Wei Wang
2018-09-18 10:34 ` Gonglei (Arei)
2018-09-06 11:30 ` [PATCH v2 8/8] perf/x86/intel/lbr: add the guest_lbr boolean to cpuc Wei Wang
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