Re: [PATCH v2 02/17] x86/hyperv: detect if Linux is the root partition

[kernel test robot]

Hi Wei,

I love your patch! Yet something to improve:

[auto build test ERROR on tip/x86/core]
[also build test ERROR on asm-generic/master iommu/next tip/timers/core pci/next linus/master v5.10-rc2 next-20201105]
[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/Wei-Liu/Introducing-Linux-root-partition-support-for-Microsoft-Hypervisor/20201106-010058
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 238c91115cd05c71447ea071624a4c9fe661f970
config: x86_64-randconfig-a004-20201104 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 09ec07827b1128504457a93dee80b2ceee1af600)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/3984ce0be67e74b8945288f1751a91615459f75e
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Wei-Liu/Introducing-Linux-root-partition-support-for-Microsoft-Hypervisor/20201106-010058
        git checkout 3984ce0be67e74b8945288f1751a91615459f75e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

All errors (new ones prefixed by >>):

>> arch/x86/kernel/cpu/mshyperv.c:247:3: error: use of undeclared identifier 'hv_root_partition'
                   hv_root_partition = true;
                   ^
   1 error generated.

vim +/hv_root_partition +247 arch/x86/kernel/cpu/mshyperv.c

   218	
   219		/*
   220		 * Extract the features and hints
   221		 */
   222		ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
   223		ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
   224		ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
   225	
   226		pr_info("Hyper-V: features 0x%x, hints 0x%x, misc 0x%x\n",
   227			ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features);
   228	
   229		ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
   230		ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
   231	
   232		pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
   233			 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
   234	
   235		/*
   236		 * Check CPU management privilege.
   237		 *
   238		 * To mirror what Windows does we should extract CPU management
   239		 * features and use the ReservedIdentityBit to detect if Linux is the
   240		 * root partition. But that requires negotiating CPU management
   241		 * interface (a process to be finalized).
   242		 *
   243		 * For now, use the privilege flag as the indicator for running as
   244		 * root.
   245		 */
   246		if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_CPU_MANAGEMENT) {
 > 247			hv_root_partition = true;
   248			pr_info("Hyper-V: running as root partition\n");
   249		}
   250	
   251		/*
   252		 * Extract host information.
   253		 */
   254		if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >=
   255		    HYPERV_CPUID_VERSION) {
   256			hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
   257			hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
   258			hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
   259			hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION);
   260	
   261			pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n",
   262				hv_host_info_eax, hv_host_info_ebx >> 16,
   263				hv_host_info_ebx & 0xFFFF, hv_host_info_ecx,
   264				hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF);
   265		}
   266	
   267		if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
   268		    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
   269			x86_platform.calibrate_tsc = hv_get_tsc_khz;
   270			x86_platform.calibrate_cpu = hv_get_tsc_khz;
   271		}
   272	
   273		if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
   274			ms_hyperv.nested_features =
   275				cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
   276		}
   277	
   278		/*
   279		 * Hyper-V expects to get crash register data or kmsg when
   280		 * crash enlightment is available and system crashes. Set
   281		 * crash_kexec_post_notifiers to be true to make sure that
   282		 * calling crash enlightment interface before running kdump
   283		 * kernel.
   284		 */
   285		if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
   286			crash_kexec_post_notifiers = true;
   287	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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