linux-kernel - Re: [PATCH v3 3/3] KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs

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Message-ID: <202208311831.zQ4oCG1b-lkp@intel.com>
Date:   Wed, 31 Aug 2022 19:12:34 +0800
From:   kernel test robot <lkp@...el.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kbuild-all@...ts.01.org, Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org, Like Xu <like.xu.linux@...il.com>
Subject: Re: [PATCH v3 3/3] KVM: VMX: Advertise PMU LBRs if and only if perf
 supports LBRs

Hi Sean,

I love your patch! Yet something to improve:

[auto build test ERROR on 372d07084593dc7a399bf9bee815711b1fb1bcf2]

url:    https://github.com/intel-lab-lkp/linux/commits/Sean-Christopherson/KVM-x86-Intel-LBR-related-perf-cleanups/20220831-080309
base:   372d07084593dc7a399bf9bee815711b1fb1bcf2
config: i386-randconfig-s001 (https://download.01.org/0day-ci/archive/20220831/202208311831.zQ4oCG1b-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://github.com/intel-lab-lkp/linux/commit/094f42374997562fff3f9f9637ec9aa8257490a0
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Sean-Christopherson/KVM-x86-Intel-LBR-related-perf-cleanups/20220831-080309
        git checkout 094f42374997562fff3f9f9637ec9aa8257490a0
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 prepare

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@...el.com>

All errors (new ones prefixed by >>):

   In file included from arch/x86/kernel/../kvm/vmx/vmx.h:11,
                    from arch/x86/kernel/asm-offsets.c:22:
   arch/x86/kernel/../kvm/vmx/capabilities.h: In function 'vmx_get_perf_capabilities':
>> arch/x86/kernel/../kvm/vmx/capabilities.h:416:9: error: implicit declaration of function 'x86_perf_get_lbr' [-Werror=implicit-function-declaration]
     416 |         x86_perf_get_lbr(&lbr);
         |         ^~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors
   make[2]: *** [scripts/Makefile.build:117: arch/x86/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [Makefile:1207: prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:222: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +/x86_perf_get_lbr +416 arch/x86/kernel/../kvm/vmx/capabilities.h

   403	
   404	static inline u64 vmx_get_perf_capabilities(void)
   405	{
   406		u64 perf_cap = PMU_CAP_FW_WRITES;
   407		struct x86_pmu_lbr lbr;
   408		u64 host_perf_cap = 0;
   409	
   410		if (!enable_pmu)
   411			return 0;
   412	
   413		if (boot_cpu_has(X86_FEATURE_PDCM))
   414			rdmsrl(MSR_IA32_PERF_CAPABILITIES, host_perf_cap);
   415	
 > 416		x86_perf_get_lbr(&lbr);
   417		if (lbr.nr)
   418			perf_cap |= host_perf_cap & PMU_CAP_LBR_FMT;
   419	
   420		if (vmx_pebs_supported()) {
   421			perf_cap |= host_perf_cap & PERF_CAP_PEBS_MASK;
   422			if ((perf_cap & PERF_CAP_PEBS_FORMAT) < 4)
   423				perf_cap &= ~PERF_CAP_PEBS_BASELINE;
   424		}
   425	
   426		return perf_cap;
   427	}
   428	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp