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Subject[PATCH v4 08/10] perf/x86: save/restore LBR_SELECT on vCPU switching
Date
The vCPU lbr event relies on the host to save/restore all the lbr
related MSRs. So add the LBR_SELECT save/restore to the related
functions for the vCPU case.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
---
arch/x86/events/intel/lbr.c | 7 +++++++
arch/x86/events/perf_event.h | 1 +
2 files changed, 8 insertions(+)

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 1d20051..0225ac9 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -383,6 +383,9 @@ static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx)

wrmsrl(x86_pmu.lbr_tos, tos);
task_ctx->lbr_stack_state = LBR_NONE;
+
+ if (cpuc->vcpu_lbr)
+ wrmsrl(MSR_LBR_SELECT, task_ctx->lbr_sel);
}

static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx)
@@ -409,6 +412,10 @@ static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx)
if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
rdmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
}
+
+ if (cpuc->vcpu_lbr)
+ rdmsrl(MSR_LBR_SELECT, task_ctx->lbr_sel);
+
task_ctx->valid_lbrs = i;
task_ctx->tos = tos;
task_ctx->lbr_stack_state = LBR_VALID;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index bbea559..ccd0215 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -653,6 +653,7 @@ struct x86_perf_task_context {
u64 lbr_from[MAX_LBR_ENTRIES];
u64 lbr_to[MAX_LBR_ENTRIES];
u64 lbr_info[MAX_LBR_ENTRIES];
+ u64 lbr_sel;
int tos;
int valid_lbrs;
int lbr_callstack_users;
--
2.7.4
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