Hi Marc, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on kvmarm/next] [also build test WARNING on next-20201210] [cannot apply to arm64/for-next/core soc/for-next arm/for-next xlnx/master linus/master kvm/linux-next v5.10-rc7] [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/Marc-Zyngier/KVM-arm64-ARMv8-3-8... base: https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git next config: arm64-defconfig (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 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 # https://github.com/0day-ci/linux/commit/af7a3cada1fa577612a86dd0a7c4016ff... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Marc-Zyngier/KVM-arm64-ARMv8-3-8-4-Nested-Virtualization-support/20201211-004741 git checkout af7a3cada1fa577612a86dd0a7c4016ffed68acc # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): arch/arm64/kvm/arch_timer.c: In function 'kvm_timer_vcpu_load_nested_switch': 656 | int hw, ret; | ^~~ vim +/ret +656 arch/arm64/kvm/arch_timer.c 652 653 static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu, 654 struct timer_map *map) 655 { 657 658 if (!irqchip_in_kernel(vcpu->kvm)) 659 return; 660 661 /* 662 * We only ever unmap the vtimer irq on a VHE system that runs nested 663 * virtualization, in which case we have both a valid emul_vtimer, 664 * emul_ptimer, direct_vtimer, and direct_ptimer. 665 * 666 * Since this is called from kvm_timer_vcpu_load(), a change between 667 * vEL2 and vEL1/0 will have just happened, and the timer_map will 668 * represent this, and therefore we switch the emul/direct mappings 669 * below. 670 */ 671 hw = kvm_vgic_get_map(vcpu, map->direct_vtimer->irq.irq); 672 if (hw < 0) { 673 kvm_vgic_unmap_phys_irq(vcpu, map->emul_vtimer->irq.irq); 674 kvm_vgic_unmap_phys_irq(vcpu, map->emul_ptimer->irq.irq); 675 676 ret = kvm_vgic_map_phys_irq(vcpu, 677 map->direct_vtimer->host_timer_irq, 678 map->direct_vtimer->irq.irq, 679 kvm_arch_timer_get_input_level); 680 ret = kvm_vgic_map_phys_irq(vcpu, 681 map->direct_ptimer->host_timer_irq, 682 map->direct_ptimer->irq.irq, 683 kvm_arch_timer_get_input_level); 684 } 685 } 686 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org