Hi Thomas, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 5833291ab6de9c3e2374336b51c814e515e8f3a5 commit: 45c7e8af4a5e3f0bea4ac209eea34118dd57ac64 MIPS: Remove KVM_TE support date: 8 months ago config: mips-randconfig-r003-20211015 (attached as .config) compiler: mipsel-linux-gcc (GCC) 11.2.0 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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 45c7e8af4a5e3f0bea4ac209eea34118dd57ac64 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash arch/mips/kvm/ 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/mips/kvm/vz.c:471: warning: Function parameter or member 'out_compare' not described in '_kvm_vz_save_htimer' arch/mips/kvm/vz.c:471: warning: Function parameter or member 'out_cause' not described in '_kvm_vz_save_htimer' arch/mips/kvm/vz.c:471: warning: Excess function parameter 'compare' description in '_kvm_vz_save_htimer' arch/mips/kvm/vz.c:471: warning: Excess function parameter 'cause' description in '_kvm_vz_save_htimer' vim +1552 arch/mips/kvm/vz.c c992a4f6a9b0a3 James Hogan 2017-03-14 1543 c992a4f6a9b0a3 James Hogan 2017-03-14 1544 /** c992a4f6a9b0a3 James Hogan 2017-03-14 1545 * kvm_trap_vz_handle_cop_unusuable() - Guest used unusable coprocessor. c992a4f6a9b0a3 James Hogan 2017-03-14 1546 * @vcpu: Virtual CPU context. c992a4f6a9b0a3 James Hogan 2017-03-14 1547 * c992a4f6a9b0a3 James Hogan 2017-03-14 1548 * Handle when the guest attempts to use a coprocessor which hasn't been allowed c992a4f6a9b0a3 James Hogan 2017-03-14 1549 * by the root context. c992a4f6a9b0a3 James Hogan 2017-03-14 1550 */ c992a4f6a9b0a3 James Hogan 2017-03-14 1551 static int kvm_trap_vz_handle_cop_unusable(struct kvm_vcpu *vcpu) c992a4f6a9b0a3 James Hogan 2017-03-14 @1552 { c992a4f6a9b0a3 James Hogan 2017-03-14 1553 u32 cause = vcpu->arch.host_cp0_cause; c992a4f6a9b0a3 James Hogan 2017-03-14 1554 enum emulation_result er = EMULATE_FAIL; c992a4f6a9b0a3 James Hogan 2017-03-14 1555 int ret = RESUME_GUEST; c992a4f6a9b0a3 James Hogan 2017-03-14 1556 c992a4f6a9b0a3 James Hogan 2017-03-14 1557 if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) { c992a4f6a9b0a3 James Hogan 2017-03-14 1558 /* c992a4f6a9b0a3 James Hogan 2017-03-14 1559 * If guest FPU not present, the FPU operation should have been c992a4f6a9b0a3 James Hogan 2017-03-14 1560 * treated as a reserved instruction! c992a4f6a9b0a3 James Hogan 2017-03-14 1561 * If FPU already in use, we shouldn't get this at all. c992a4f6a9b0a3 James Hogan 2017-03-14 1562 */ c992a4f6a9b0a3 James Hogan 2017-03-14 1563 if (WARN_ON(!kvm_mips_guest_has_fpu(&vcpu->arch) || c992a4f6a9b0a3 James Hogan 2017-03-14 1564 vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)) { c992a4f6a9b0a3 James Hogan 2017-03-14 1565 preempt_enable(); c992a4f6a9b0a3 James Hogan 2017-03-14 1566 return EMULATE_FAIL; c992a4f6a9b0a3 James Hogan 2017-03-14 1567 } c992a4f6a9b0a3 James Hogan 2017-03-14 1568 c992a4f6a9b0a3 James Hogan 2017-03-14 1569 kvm_own_fpu(vcpu); c992a4f6a9b0a3 James Hogan 2017-03-14 1570 er = EMULATE_DONE; c992a4f6a9b0a3 James Hogan 2017-03-14 1571 } c992a4f6a9b0a3 James Hogan 2017-03-14 1572 /* other coprocessors not handled */ c992a4f6a9b0a3 James Hogan 2017-03-14 1573 c992a4f6a9b0a3 James Hogan 2017-03-14 1574 switch (er) { c992a4f6a9b0a3 James Hogan 2017-03-14 1575 case EMULATE_DONE: c992a4f6a9b0a3 James Hogan 2017-03-14 1576 ret = RESUME_GUEST; c992a4f6a9b0a3 James Hogan 2017-03-14 1577 break; c992a4f6a9b0a3 James Hogan 2017-03-14 1578 c992a4f6a9b0a3 James Hogan 2017-03-14 1579 case EMULATE_FAIL: c34b26b98caca4 Tianjia Zhang 2020-06-23 1580 vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; c992a4f6a9b0a3 James Hogan 2017-03-14 1581 ret = RESUME_HOST; c992a4f6a9b0a3 James Hogan 2017-03-14 1582 break; c992a4f6a9b0a3 James Hogan 2017-03-14 1583 c992a4f6a9b0a3 James Hogan 2017-03-14 1584 default: c992a4f6a9b0a3 James Hogan 2017-03-14 1585 BUG(); c992a4f6a9b0a3 James Hogan 2017-03-14 1586 } c992a4f6a9b0a3 James Hogan 2017-03-14 1587 return ret; c992a4f6a9b0a3 James Hogan 2017-03-14 1588 } c992a4f6a9b0a3 James Hogan 2017-03-14 1589 :::::: The code at line 1552 was first introduced by commit :::::: c992a4f6a9b0a37c8bd7dfc727ecc3fed125c16b KVM: MIPS: Implement VZ support :::::: TO: James Hogan <james.hogan(a)imgtec.com&gt; :::::: CC: James Hogan <james.hogan(a)imgtec.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org