On Fri, Nov 10, 2023, kernel test robot wrote: > Hi, > > kernel test robot noticed the following build errors: > > [auto build test ERROR on kvm/queue] > [also build test ERROR on linus/master next-20231109] > [cannot apply to mst-vhost/linux-next kvm/linux-next v6.6] > [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#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/isaku-yamahata-intel-com/KVM-x86-Make-the-hardcoded-APIC-bus-frequency-vm-variable/20231108-032736 > base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue > patch link: https://lore.kernel.org/r/70c2a2277f57b804c715c5b4b4aa0b3561ed6a4f.1699383993.git.isaku.yamahata%40intel.com > patch subject: [PATCH 2/2] KVM: X86: Add a capability to configure bus frequency for APIC timer > config: i386-buildonly-randconfig-002-20231109 (https://download.01.org/0day-ci/archive/20231110/202311100209.zIaZqZhg-lkp@xxxxxxxxx/config) > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231110/202311100209.zIaZqZhg-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 <yujie.liu@xxxxxxxxx> > | Closes: https://lore.kernel.org/r/202311100209.zIaZqZhg-lkp@xxxxxxxxx/ > > All errors (this is a 32-bit build, new ones prefixed by >>): > > ld: arch/x86/kvm/x86.o: in function `kvm_vm_ioctl_enable_cap': > >> x86.c:(.text+0x1265b): undefined reference to `__udivdi3' Heh, this inscrutable error is due to 64-bit division on 32-bit kernels. u64 bus_frequency = cap->args[0]; u64 bus_cycle_ns; if (!bus_frequency) return -EINVAL; bus_cycle_ns = 1000000000UL / bus_frequency; <======== I don't see any reason to allow 64-bit values, e.g. Intel's CPUID 0x15 only supports a 32-bit frequency in Hz. I.e. just truncate it to a u32.
