Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: fYumHZspw7kdG5q1iG1KaAqHXFQR6OB/jbNicHXGFxO62P1C/6a6tA5gMnowPKXhvfRLMnTySp
 Wb8fYAxC5ZjQ==
IronPort-SDR: +6uqcODxV7agIa/a5IDTBQV841236MwgX7BDgqo0y3JmhPsw3kZInglefFDxVgRyGtnoLGy3RN
 w+ZW3mivIxug==
Subject: Re: [PATCH v5 0/5] perf/x86: Some minor changes to support guest Arch
 LBR
From:   Like Xu <like.xu@linux.intel.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     pbonzini@redhat.com, Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Kan Liang <kan.liang@linux.intel.com>, wei.w.wang@intel.com,
        x86@kernel.org, linux-kernel@vger.kernel.org,
        Namhyung Kim <namhyung@kernel.org>
References: <20210326011918.183685-1-like.xu@linux.intel.com>
 <91102eac-a315-3165-1670-8313176657f1@linux.intel.com>
Organization: Intel OTC
Message-ID: <3106c3f9-45c7-d286-5a56-8c6eda8990f2@linux.intel.com>
Date:   Fri, 9 Apr 2021 16:51:02 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.9.0
MIME-Version: 1.0
In-Reply-To: <91102eac-a315-3165-1670-8313176657f1@linux.intel.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Precedence: bulk

Em, does anyone want to review these minor changes？

I believe some of them solve the real problem.

On 2021/4/6 11:20, Like Xu wrote:
> Hi all, do we have any comments on this patch set?
> 
> On 2021/3/26 9:19, Like Xu wrote:
>> Hi Peter,
>>
>> Please help review these minor perf/x86 changes in this patch set,
>> and we need some of them to support Guest Architectural LBR in KVM.
>>
>> This version keeps reserve_lbr_buffers() as is because the LBR xsave
>> buffer is a per-CPU buffer, not a per-event buffer. We only need to
>> allocate the buffer once when initializing the first event.
>>
>> If you are interested in the KVM emulation, please check
>> https://lore.kernel.org/kvm/20210314155225.206661-1-like.xu@linux.intel.com/
>>
>> Please check more details in each commit and feel free to comment.
>>
>> Previous:
>> https://lore.kernel.org/lkml/20210322060635.821531-1-like.xu@linux.intel.com/ 
>>
>>
>> v4->v5 Changelog:
>> - Add "Tested-by: Kan Liang"
>> - Make the commit message simpler
>> - Make check_msr() to ignore msr==0
>> - Use kmem_cache_alloc_node() [Namhyung]
>>
>> Like Xu (5):
>>    perf/x86/intel: Fix the comment about guest LBR support on KVM
>>    perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers
>>    perf/x86: Skip checking MSR for MSR 0x000
>>    perf/x86/lbr: Move cpuc->lbr_xsave allocation out of sleeping region
>>    perf/x86: Move ARCH_LBR_CTL_MASK definition to include/asm/msr-index.h
>>
>>   arch/x86/events/core.c           |  8 +++++---
>>   arch/x86/events/intel/bts.c      |  2 +-
>>   arch/x86/events/intel/core.c     |  7 +++----
>>   arch/x86/events/intel/lbr.c      | 29 ++++++++++++++++++-----------
>>   arch/x86/events/perf_event.h     |  8 +++++++-
>>   arch/x86/include/asm/msr-index.h |  1 +
>>   6 files changed, 35 insertions(+), 20 deletions(-)
>>
>