Re: [PATCH v7 05/15] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_CTL for guest Arch LBR

From: kernel test robot
Date: Fri Aug 06 2021 - 12:27:33 EST


Hi Yang,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on v5.14-rc4]
[also build test WARNING on next-20210805]
[cannot apply to kvm/queue tip/perf/core tip/x86/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Yang-Weijiang/Introduce-Architectural-LBR-for-vPMU/20210806-153154
base: c500bee1c5b2f1d59b1081ac879d73268ab0ff17
config: x86_64-rhel-8.3-kselftests (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.3-348-gf0e6938b-dirty
# https://github.com/0day-ci/linux/commit/1d5b4967a3c4553c3648638f1189dcbff631328e
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Yang-Weijiang/Introduce-Architectural-LBR-for-vPMU/20210806-153154
git checkout 1d5b4967a3c4553c3648638f1189dcbff631328e
# save the attached .config to linux build tree
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/kvm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>


sparse warnings: (new ones prefixed by >>)
arch/x86/kvm/vmx/pmu_intel.c: note: in included file (through arch/x86/kvm/vmx/vmx_ops.h, arch/x86/kvm/vmx/vmx.h, arch/x86/kvm/vmx/nested.h):
>> arch/x86/kvm/vmx/evmcs.h:81:30: sparse: sparse: cast truncates bits from constant value (a058a becomes 58a)
>> arch/x86/kvm/vmx/evmcs.h:81:30: sparse: sparse: cast truncates bits from constant value (a058a becomes 58a)
arch/x86/kvm/vmx/evmcs.h:81:30: sparse: sparse: cast truncates bits from constant value (a008a becomes 8a)
arch/x86/kvm/vmx/evmcs.h:81:30: sparse: sparse: cast truncates bits from constant value (a008a becomes 8a)
arch/x86/kvm/vmx/evmcs.h:81:30: sparse: sparse: cast truncates bits from constant value (a008a becomes 8a)

vim +81 arch/x86/kvm/vmx/evmcs.h

75edce8a45486f arch/x86/kvm/vmx/evmcs.h Sean Christopherson 2018-12-03 77
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 78 static __always_inline int get_evmcs_offset(unsigned long field,
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 79 u16 *clean_field)
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 80 {
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 @81 unsigned int index = ROL16(field, 6);
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 82 const struct evmcs_field *evmcs_field;
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 83
75edce8a45486f arch/x86/kvm/vmx/evmcs.h Sean Christopherson 2018-12-03 84 if (unlikely(index >= nr_evmcs_1_fields)) {
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 85 WARN_ONCE(1, "KVM: accessing unsupported EVMCS field %lx\n",
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 86 field);
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 87 return -ENOENT;
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 88 }
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 89
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 90 evmcs_field = &vmcs_field_to_evmcs_1[index];
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 91
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 92 if (clean_field)
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 93 *clean_field = evmcs_field->clean_field;
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 94
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 95 return evmcs_field->offset;
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 96 }
773e8a0425c923 arch/x86/kvm/vmx_evmcs.h Vitaly Kuznetsov 2018-03-20 97

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