Re: [PATCH v9 00/10] Guest Last Branch Recording Enabling

From: "Xu, Like" <like.xu@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: kvm@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
	Jim Mattson <jmattson@google.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Joerg Roedel <joro@8bytes.org>,
	Liran Alon <liran.alon@oracle.com>,
	Liang Kan <kan.liang@linux.intel.com>,
	Wei Wang <wei.w.wang@intel.com>,
	linux-kernel@vger.kernel.org,
	Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: Re: [PATCH v9 00/10] Guest Last Branch Recording Enabling
Date: Fri, 20 Mar 2020 16:45:45 +0800	[thread overview]
Message-ID: <446eef98-4d9f-4a9b-bdae-d29e36f6e07e@intel.com> (raw)
In-Reply-To: <20200313021616.112322-1-like.xu@linux.intel.com>

Hi Peter,
any comments on the host perf changes?

Hi Paolo,
any comments on the kvm changes? Isn't this feature interesting to you?

Just kindly ping.

Thanks,
Like Xu

On 2020/3/13 10:16, Like Xu wrote:
> Hi all,
>
> Please help review your interesting parts in this stable version,
> e.g. the first four patches involve the perf event subsystem
> and the fifth patch concerns the KVM userspace interface.

> v8->v9 Changelog:
> - using guest_lbr_constraint to create guest LBR event without hw counter;
>    (please check perf changes in patch 0003)
> - rename 'cpuc->vcpu_lbr' to 'cpuc->guest_lbr_enabled';
>    (please check host LBR changes in patch 0004)
> - replace 'pmu->lbr_used' mechanism with lazy release kvm_pmu_lbr_cleanup();
> - refactor IA32_PERF_CAPABILITIES trap via get_perf_capabilities();
> - refactor kvm_pmu_lbr_enable() with kvm_pmu_lbr_setup();
> - simplify model-specific LBR functionality check;
> - rename x86_perf_get_lbr_stack to x86_perf_get_lbr;
> - rename intel_pmu_lbr_confirm() to kvm_pmu_availability_check();
>
> Previous:
> https://lore.kernel.org/lkml/1565075774-26671-1-git-send-email-wei.w.wang@intel.com/
>
> Like Xu (7):
>    perf/x86/lbr: Add interface to get basic information about LBR stack
>    perf/x86: Add constraint to create guest LBR event without hw counter
>    perf/x86: Keep LBR stack unchanged on the host for guest LBR event
>    KVM: x86: Add KVM_CAP_X86_GUEST_LBR interface to dis/enable LBR
>      feature
>    KVM: x86/pmu: Add LBR feature emulation via guest LBR event
>    KVM: x86/pmu: Release guest LBR event via vPMU lazy release mechanism
>    KVM: x86: Expose MSR_IA32_PERF_CAPABILITIES to guest for LBR record
>      format
>
> Wei Wang (3):
>    perf/x86: Fix msr variable type for the LBR msrs
>    KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
>    KVM: x86: Remove the common trap handler of the MSR_IA32_DEBUGCTLMSR
>
>   Documentation/virt/kvm/api.rst    |  28 +++
>   arch/x86/events/core.c            |   9 +-
>   arch/x86/events/intel/core.c      |  29 +++
>   arch/x86/events/intel/lbr.c       |  55 +++++-
>   arch/x86/events/perf_event.h      |  21 ++-
>   arch/x86/include/asm/kvm_host.h   |   7 +
>   arch/x86/include/asm/perf_event.h |  24 ++-
>   arch/x86/kvm/cpuid.c              |   3 +-
>   arch/x86/kvm/pmu.c                |  28 ++-
>   arch/x86/kvm/pmu.h                |  26 ++-
>   arch/x86/kvm/pmu_amd.c            |   7 +-
>   arch/x86/kvm/vmx/pmu_intel.c      | 291 ++++++++++++++++++++++++++++--
>   arch/x86/kvm/vmx/vmx.c            |   4 +-
>   arch/x86/kvm/vmx/vmx.h            |   2 +
>   arch/x86/kvm/x86.c                |  42 +++--
>   include/linux/perf_event.h        |   7 +
>   include/uapi/linux/kvm.h          |   1 +
>   kernel/events/core.c              |   7 -
>   tools/include/uapi/linux/kvm.h    |   1 +
>   19 files changed, 540 insertions(+), 52 deletions(-)
>