[xinli-intel-fred-public:intel-lkp 20/21] arch/x86/kvm/vmx/tdx.c:779:33: error: call to undeclared function 'read_msr'; ISO C99 and later do not support implicit function declarations

[xinli-intel-fred-public:intel-lkp 20/21] arch/x86/kvm/vmx/tdx.c:779:33: error: call to undeclared function 'read_msr'; ISO C99 and later do not support implicit function declarations

[kernel test robot]

tree:   https://github.com/xinli-intel/linux-fred-public.git intel-lkp
head:   f5a7aa46f2de853090449e1a5bb733628907c08b
commit: 4c8b4516efd0095821b118c1d1beaa3fd32d6dbe [20/21] KVM: VMX: Remove read_msr() defined in <asm/kvm_host.h>
config: x86_64-buildonly-randconfig-006-20250625 (https://download.01.org/0day-ci/archive/20250625/202506251414.ubuFeMUa-lkp@intel.com/config)
compiler: clang version 20.1.7 (https://github.com/llvm/llvm-project 6146a88f60492b520a36f8f8f3231e15f3cc6082)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250625/202506251414.ubuFeMUa-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202506251414.ubuFeMUa-lkp@intel.com/

All errors (new ones prefixed by >>):

>> arch/x86/kvm/vmx/tdx.c:779:33: error: call to undeclared function 'read_msr'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     779 |                 vt->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE);
         |                                               ^
   1 error generated.


vim +/read_msr +779 arch/x86/kvm/vmx/tdx.c

90cfe144c8ed98 Sean Christopherson 2025-02-22  764  
81bf40d54cd56e Isaku Yamahata      2025-01-29  765  /*
81bf40d54cd56e Isaku Yamahata      2025-01-29  766   * Compared to vmx_prepare_switch_to_guest(), there is not much to do
81bf40d54cd56e Isaku Yamahata      2025-01-29  767   * as SEAMCALL/SEAMRET calls take care of most of save and restore.
81bf40d54cd56e Isaku Yamahata      2025-01-29  768   */
81bf40d54cd56e Isaku Yamahata      2025-01-29  769  void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
81bf40d54cd56e Isaku Yamahata      2025-01-29  770  {
81bf40d54cd56e Isaku Yamahata      2025-01-29  771  	struct vcpu_vt *vt = to_vt(vcpu);
81bf40d54cd56e Isaku Yamahata      2025-01-29  772  
81bf40d54cd56e Isaku Yamahata      2025-01-29  773  	if (vt->guest_state_loaded)
81bf40d54cd56e Isaku Yamahata      2025-01-29  774  		return;
81bf40d54cd56e Isaku Yamahata      2025-01-29  775  
81bf40d54cd56e Isaku Yamahata      2025-01-29  776  	if (likely(is_64bit_mm(current->mm)))
81bf40d54cd56e Isaku Yamahata      2025-01-29  777  		vt->msr_host_kernel_gs_base = current->thread.gsbase;
81bf40d54cd56e Isaku Yamahata      2025-01-29  778  	else
81bf40d54cd56e Isaku Yamahata      2025-01-29 @779  		vt->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE);
81bf40d54cd56e Isaku Yamahata      2025-01-29  780  
8af099037527c5 Adrian Hunter       2025-01-29  781  	vt->host_debugctlmsr = get_debugctlmsr();
8af099037527c5 Adrian Hunter       2025-01-29  782  
81bf40d54cd56e Isaku Yamahata      2025-01-29  783  	vt->guest_state_loaded = true;
81bf40d54cd56e Isaku Yamahata      2025-01-29  784  }
81bf40d54cd56e Isaku Yamahata      2025-01-29  785  

:::::: The code at line 779 was first introduced by commit
:::::: 81bf40d54cd56e33b4cd381cc719efaa53832468 KVM: TDX: vcpu_run: save/restore host state(host kernel gs)

:::::: TO: Isaku Yamahata <isaku.yamahata@intel.com>
:::::: CC: Paolo Bonzini <pbonzini@redhat.com>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki