Messages in this thread | | | From | Alexander Shishkin <> | Subject | RE: [PATCH v1 3/8] KVM: x86: Allocate performance counter for PEBS event | Date | Wed, 30 Oct 2019 08:42:10 +0200 |
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"Kang, Luwei" <luwei.kang@intel.com> writes:
>> > static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, >> > unsigned config, bool exclude_user, >> > bool exclude_kernel, bool intr, >> > - bool in_tx, bool in_tx_cp) >> > + bool in_tx, bool in_tx_cp, bool pebs) >> > { >> > struct perf_event *event; >> > struct perf_event_attr attr = { >> > @@ -111,9 +111,12 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, >> > .exclude_user = exclude_user, >> > .exclude_kernel = exclude_kernel, >> > .config = config, >> > + .precise_ip = pebs ? 1 : 0, >> > + .aux_output = pebs ? 1 : 0, >> >> srsly? > > Hi Peter, > Thanks for review. For aux_output, I think it should be set 1 when the guest wants to enabled PEBS by Intel PT.
attr.aux_output==1 means your group leader should be an intel_pt event for this to succeed. Luckily for this instance, perf_event_create_kernel_counter() doesn't actually check the attr.aux_output.
Also, does 'bool pebs' mean PEBS-via-PT or just a PEBS counter? Or does it mean that in kvm it's the same thing?
Regards, -- Alex
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