Re: [PATCH v5 2/5] x86/kexec: do unconditional WBINVD for bare-metal in relocate_kernel()

[kernel test robot <lkp@intel.com>]

Hi Kai,

kernel test robot noticed the following build warnings:

[auto build test WARNING on b8c7cbc324dc17b9e42379b42603613580bec2d8]

url:    https://github.com/intel-lab-lkp/linux/commits/Kai-Huang/x86-kexec-do-unconditional-WBINVD-for-bare-metal-in-stop_this_cpu/20240815-205623
base:   b8c7cbc324dc17b9e42379b42603613580bec2d8
patch link:    https://lore.kernel.org/r/47d9f1150a6852c9a403b9e25858f5658c50a51d.1723723470.git.kai.huang%40intel.com
patch subject: [PATCH v5 2/5] x86/kexec: do unconditional WBINVD for bare-metal in relocate_kernel()
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20240816/202408160236.7eD455CA-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240816/202408160236.7eD455CA-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/202408160236.7eD455CA-lkp@intel.com/

All warnings (new ones prefixed by >>):

   arch/x86/kernel/machine_kexec_64.c: In function 'machine_kexec':
>> arch/x86/kernel/machine_kexec_64.c:325:22: warning: variable 'host_mem_enc_active' set but not used [-Wunused-but-set-variable]
     325 |         unsigned int host_mem_enc_active;
         |                      ^~~~~~~~~~~~~~~~~~~


vim +/host_mem_enc_active +325 arch/x86/kernel/machine_kexec_64.c

5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  317  
5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  318  /*
5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  319   * Do not allocate memory (or fail in any way) in machine_kexec().
5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  320   * We are past the point of no return, committed to rebooting now.
5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  321   */
3ab83521378268 arch/x86/kernel/machine_kexec_64.c Huang Ying        2008-07-25  322  void machine_kexec(struct kimage *image)
5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  323  {
4bfaaef01a1bad arch/x86_64/kernel/machine_kexec.c Magnus Damm       2006-09-26  324  	unsigned long page_list[PAGES_NR];
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02 @325  	unsigned int host_mem_enc_active;
fee7b0d84cc8c7 arch/x86/kernel/machine_kexec_64.c Huang Ying        2009-03-10  326  	int save_ftrace_enabled;
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  327  	void *control_page;
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  328  
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  329  	/*
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  330  	 * This must be done before load_segments() since if call depth tracking
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  331  	 * is used then GS must be valid to make any function calls.
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  332  	 */
93c1800b3799f1 arch/x86/kernel/machine_kexec_64.c David Kaplan      2024-06-02  333  	host_mem_enc_active = cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT);
5234f5eb04abbb arch/x86_64/kernel/machine_kexec.c Eric W. Biederman 2005-06-25  334  

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