tree: https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git hyperv-next head: 0d9f8d427756841b79df5da8bed98dc113299637 commit: 325d7a85e1ea52c5ca82b246c332e08939b085df [3/5] Drivers: hv: Make portions of Hyper-V init code be arch neutral config: x86_64-kexec (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/commit/?... git remote add hyperv-linux https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git git fetch --no-tags hyperv-linux hyperv-next git checkout 325d7a85e1ea52c5ca82b246c332e08939b085df # save the attached .config to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): ld: arch/x86/kernel/cpu/mshyperv.o: in function `ms_hyperv_init_platform': ld: arch/x86/kernel/cpu/mshyperv.c:264: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.c:265: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.c:269: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.o:arch/x86/kernel/cpu/mshyperv.c:269: more undefined references to `ms_hyperv' follow ld: arch/x86/kernel/cpu/mshyperv.o: in function `ms_hyperv_init_platform': ld: arch/x86/kernel/cpu/mshyperv.c:310: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.c:310: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.c:316: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.c:317: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.c:320: undefined reference to `ms_hyperv' ld: arch/x86/kernel/cpu/mshyperv.o:arch/x86/kernel/cpu/mshyperv.c:318: more undefined references to `ms_hyperv' follow vim +262 arch/x86/kernel/cpu/mshyperv.c f7c0f50f1857c1 Andrea Parri 2019-10-15 258 a2a47c6c3d1a7c Ky Srinivasan 2010-05-06 259 /* e08cae4181af94 H. Peter Anvin 2010-05-07 260 * Extract the features and hints a2a47c6c3d1a7c Ky Srinivasan 2010-05-06 261 */ e08cae4181af94 H. Peter Anvin 2010-05-07 @262 ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); 6dc2a774cb4fdb Sunil Muthuswamy 2021-03-23 @263 ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES); cc2dd4027a43bb Denis V. Lunev 2015-08-01 264 ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); e08cae4181af94 H. Peter Anvin 2010-05-07 265 ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); a2a47c6c3d1a7c Ky Srinivasan 2010-05-06 266 a6c776a952175e Vineeth Pillai 2021-06-03 267 hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); a6c776a952175e Vineeth Pillai 2021-06-03 268 6dc2a774cb4fdb Sunil Muthuswamy 2021-03-23 269 pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", 6dc2a774cb4fdb Sunil Muthuswamy 2021-03-23 270 ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, 6dc2a774cb4fdb Sunil Muthuswamy 2021-03-23 271 ms_hyperv.misc_features); 6f4151c89b7d03 K. Y. Srinivasan 2011-09-07 272 415bd1cd3a4289 Vitaly Kuznetsov 2018-03-20 273 ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); 415bd1cd3a4289 Vitaly Kuznetsov 2018-03-20 274 ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS); dd018597a074bc Vitaly Kuznetsov 2017-06-25 275 dd018597a074bc Vitaly Kuznetsov 2017-06-25 276 pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n", dd018597a074bc Vitaly Kuznetsov 2017-06-25 277 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index); dd018597a074bc Vitaly Kuznetsov 2017-06-25 278 e997720202b363 Wei Liu 2021-02-03 279 /* e997720202b363 Wei Liu 2021-02-03 280 * Check CPU management privilege. e997720202b363 Wei Liu 2021-02-03 281 * e997720202b363 Wei Liu 2021-02-03 282 * To mirror what Windows does we should extract CPU management e997720202b363 Wei Liu 2021-02-03 283 * features and use the ReservedIdentityBit to detect if Linux is the e997720202b363 Wei Liu 2021-02-03 284 * root partition. But that requires negotiating CPU management e997720202b363 Wei Liu 2021-02-03 285 * interface (a process to be finalized). e997720202b363 Wei Liu 2021-02-03 286 * e997720202b363 Wei Liu 2021-02-03 287 * For now, use the privilege flag as the indicator for running as e997720202b363 Wei Liu 2021-02-03 288 * root. e997720202b363 Wei Liu 2021-02-03 289 */ e997720202b363 Wei Liu 2021-02-03 290 if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_CPU_MANAGEMENT) { e997720202b363 Wei Liu 2021-02-03 @291 hv_root_partition = true; e997720202b363 Wei Liu 2021-02-03 292 pr_info("Hyper-V: running as root partition\n"); e997720202b363 Wei Liu 2021-02-03 293 } e997720202b363 Wei Liu 2021-02-03 294 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 295 /* 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 296 * Extract host information. 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 297 */ a6c776a952175e Vineeth Pillai 2021-06-03 298 if (hv_max_functions_eax >= HYPERV_CPUID_VERSION) { 415bd1cd3a4289 Vitaly Kuznetsov 2018-03-20 299 hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION); 415bd1cd3a4289 Vitaly Kuznetsov 2018-03-20 300 hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION); 415bd1cd3a4289 Vitaly Kuznetsov 2018-03-20 301 hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION); 415bd1cd3a4289 Vitaly Kuznetsov 2018-03-20 302 hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION); 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 303 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 304 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n", 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 305 hv_host_info_eax, hv_host_info_ebx >> 16, 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 306 hv_host_info_ebx & 0xFFFF, hv_host_info_ecx, 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 307 hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF); 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 308 } 8de8af7e0873c4 K. Y. Srinivasan 2017-01-19 309 e1471463180ddc Joseph Salisbury 2020-09-26 310 if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS && 71c2a2d0a81f09 Vitaly Kuznetsov 2017-06-22 311 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { 71c2a2d0a81f09 Vitaly Kuznetsov 2017-06-22 312 x86_platform.calibrate_tsc = hv_get_tsc_khz; 71c2a2d0a81f09 Vitaly Kuznetsov 2017-06-22 313 x86_platform.calibrate_cpu = hv_get_tsc_khz; 71c2a2d0a81f09 Vitaly Kuznetsov 2017-06-22 314 } 71c2a2d0a81f09 Vitaly Kuznetsov 2017-06-22 315 6dc2a774cb4fdb Sunil Muthuswamy 2021-03-23 316 if (ms_hyperv.priv_high & HV_ISOLATION) { a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 317) ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG); a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 318) ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG); a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 319) a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 320) pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n", a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 321) ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b); a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 322) } a6c76bb08dc7f7 Andrea Parri (Microsoft 2021-02-01 323) a6c776a952175e Vineeth Pillai 2021-06-03 324 if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) { 5431390b303962 Vitaly Kuznetsov 2018-03-20 325 ms_hyperv.nested_features = 5431390b303962 Vitaly Kuznetsov 2018-03-20 326 cpuid_eax(HYPERV_CPUID_NESTED_FEATURES); a6c776a952175e Vineeth Pillai 2021-06-03 327 pr_info("Hyper-V: Nested features: 0x%x\n", a6c776a952175e Vineeth Pillai 2021-06-03 328 ms_hyperv.nested_features); 5431390b303962 Vitaly Kuznetsov 2018-03-20 329 } 5431390b303962 Vitaly Kuznetsov 2018-03-20 330 a11589563e96bf Tianyu Lan 2020-04-06 331 /* a11589563e96bf Tianyu Lan 2020-04-06 332 * Hyper-V expects to get crash register data or kmsg when a11589563e96bf Tianyu Lan 2020-04-06 333 * crash enlightment is available and system crashes. Set a11589563e96bf Tianyu Lan 2020-04-06 334 * crash_kexec_post_notifiers to be true to make sure that a11589563e96bf Tianyu Lan 2020-04-06 335 * calling crash enlightment interface before running kdump a11589563e96bf Tianyu Lan 2020-04-06 336 * kernel. a11589563e96bf Tianyu Lan 2020-04-06 337 */ a11589563e96bf Tianyu Lan 2020-04-06 338 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) a11589563e96bf Tianyu Lan 2020-04-06 339 crash_kexec_post_notifiers = true; a11589563e96bf Tianyu Lan 2020-04-06 340 :::::: The code at line 262 was first introduced by commit :::::: e08cae4181af9483b04ecfac48f01c8e5a5f27bf x86: Clean up the hypervisor layer :::::: TO: H. Peter Anvin <hpa(a)zytor.com&gt; :::::: CC: H. Peter Anvin <hpa(a)zytor.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org