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

From: kernel test robot
Date: Thu Nov 05 2020 - 15:24:28 EST


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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