From: Peter Zijlstra <peterz@infradead.org>
To: "Kang, Luwei" <luwei.kang@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"rkrcmar@redhat.com" <rkrcmar@redhat.com>,
"Christopherson, Sean J" <sean.j.christopherson@intel.com>,
"vkuznets@redhat.com" <vkuznets@redhat.com>,
"wanpengli@tencent.com" <wanpengli@tencent.com>,
"jmattson@google.com" <jmattson@google.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"bp@alien8.de" <bp@alien8.de>, "hpa@zytor.com" <hpa@zytor.com>,
"x86@kernel.org" <x86@kernel.org>,
"ak@linux.intel.com" <ak@linux.intel.com>,
"thomas.lendacky@amd.com" <thomas.lendacky@amd.com>,
"acme@kernel.org" <acme@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"jolsa@redhat.com" <jolsa@redhat.com>,
"namhyung@kernel.org" <namhyung@kernel.org>
Subject: Re: [PATCH v1 3/8] KVM: x86: Allocate performance counter for PEBS event
Date: Wed, 30 Oct 2019 10:51:07 +0100 [thread overview]
Message-ID: <20191030095107.GS4097@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <82D7661F83C1A047AF7DC287873BF1E173835CAA@SHSMSX104.ccr.corp.intel.com>
On Wed, Oct 30, 2019 at 06:49:42AM +0000, Kang, Luwei wrote:
> > >> > 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?
>
> It is the same thing. Allocate a counter for PEBS event and use PEBS-via-PT.
It is not the same thing, obviously. It strictly means pebs-over-pt
here.
next prev parent reply other threads:[~2019-10-30 9:51 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-27 23:11 [PATCH v1 0/8] PEBS enabling in KVM guest Luwei Kang
2019-10-27 23:11 ` [PATCH v1 1/8] KVM: x86: Add base address parameter for get_fixed_pmc function Luwei Kang
2019-10-27 23:11 ` [PATCH v1 2/8] KVM: x86: PEBS output to Intel PT MSRs emulation Luwei Kang
2019-10-29 15:02 ` Peter Zijlstra
2019-10-30 4:06 ` Kang, Luwei
2019-10-27 23:11 ` [PATCH v1 3/8] KVM: x86: Allocate performance counter for PEBS event Luwei Kang
2019-10-29 14:46 ` Peter Zijlstra
2019-10-30 4:06 ` Kang, Luwei
2019-10-30 6:42 ` Alexander Shishkin
2019-10-30 6:49 ` Kang, Luwei
2019-10-30 9:51 ` Peter Zijlstra [this message]
2019-10-30 9:50 ` Peter Zijlstra
2019-10-30 9:49 ` Peter Zijlstra
2019-10-30 13:41 ` Alexander Shishkin
2019-10-31 11:10 ` Kang, Luwei
2019-11-06 7:44 ` Kang, Luwei
2019-10-27 23:11 ` [PATCH v1 4/8] KVM: x86: Aviod clear the PEBS counter when PEBS enabled in guest Luwei Kang
2019-10-29 14:55 ` Peter Zijlstra
2019-10-30 4:06 ` Kang, Luwei
2019-10-27 23:11 ` [PATCH v1 5/8] KVM: X86: Expose PDCM cpuid to guest Luwei Kang
2019-10-27 23:11 ` [PATCH v1 6/8] KVM: X86: MSR_IA32_PERF_CAPABILITIES MSR emulation Luwei Kang
2019-10-27 23:11 ` [PATCH v1 7/8] KVM: x86: Expose PEBS feature to guest Luwei Kang
2019-10-29 15:05 ` Peter Zijlstra
2019-10-30 4:07 ` Kang, Luwei
2019-10-30 9:52 ` Peter Zijlstra
2019-10-31 4:21 ` Kang, Luwei
2019-10-27 23:11 ` [PATCH v1 8/8] perf/x86: Add event owner check when PEBS output to Intel PT Luwei Kang
2019-10-29 15:13 ` Peter Zijlstra
2019-10-30 4:07 ` Kang, Luwei
2019-10-30 9:54 ` Peter Zijlstra
2019-10-31 6:55 ` Kang, Luwei
2019-10-31 7:39 ` Alexander Shishkin
2019-10-31 10:31 ` Kang, Luwei
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