Hi Oliver, kernel test robot noticed the following build warnings: [auto build test WARNING on ce9ecca0238b140b88f43859b211c9fdfd8e5b70] url: https://github.com/intel-lab-lkp/linux/commits/Oliver-Upton/KVM-arm64-Allow-userspace-to-get-the-writable-masks-for-feature-ID-registers/20230921-023547 base: ce9ecca0238b140b88f43859b211c9fdfd8e5b70 patch link: https://lore.kernel.org/r/20230920183310.1163034-11-oliver.upton%40linux.dev patch subject: [PATCH v10 10/12] KVM: arm64: Document vCPU feature selection UAPIs reproduce: (https://download.01.org/0day-ci/archive/20230927/202309271037.rM4DMYYZ-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202309271037.rM4DMYYZ-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> Documentation/virt/kvm/arm/vcpu-features.rst:13: WARNING: undefined label: kvm_arm_vcpu_init (if the link has no caption the label must precede a section header) >> Documentation/virt/kvm/arm/vcpu-features.rst:30: WARNING: undefined label: kvm_arm_get_reg_writable_masks (if the link has no caption the label must precede a section header) vim +13 Documentation/virt/kvm/arm/vcpu-features.rst 12 > 13 The ``KVM_ARM_VCPU_INIT`` ioctl accepts a bitmap of feature flags 14 (``struct kvm_vcpu_init::features``). Features enabled by this interface are 15 *opt-in* and may change/extend UAPI. See :ref:`KVM_ARM_VCPU_INIT` for complete 16 documentation of the features controlled by the ioctl. 17 18 Otherwise, all CPU features supported by KVM are described by the architected 19 ID registers. 20 21 The ID Registers 22 ================ 23 24 The Arm architecture specifies a range of *ID Registers* that describe the set 25 of architectural features supported by the CPU implementation. KVM initializes 26 the guest's ID registers to the maximum set of CPU features supported by the 27 system. The ID register values are VM-scoped in KVM, meaning that the values 28 are identical for all vCPUs in a VM. 29 > 30 KVM allows userspace to *opt-out* of certain CPU features described by the ID 31 registers by writing values to them via the ``KVM_SET_ONE_REG`` ioctl. The ID 32 registers are mutable until the VM has started, i.e. userspace has called 33 ``KVM_RUN`` on at least one vCPU in the VM. Userspace can discover what fields 34 are mutable in the ID registers using the ``KVM_ARM_GET_REG_WRITABLE_MASKS``. 35 See the :ref:`ioctl documentation <KVM_ARM_GET_REG_WRITABLE_MASKS>` for more 36 details. 37 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
