tree: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue head: 42ac670e03c13e78b43177569bea49540d22661e commit: 3bd33d3f648e99bdf93f327f2abc40962d740b9c [329/331] kvm: x86: Allow userspace to handle emulation errors config: x86_64-randconfig-a002-20210622 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 7c8a507272587f181ec29401453949ebcd8fec65) 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://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=3bd33d3f648e99bdf93f327f2abc40962d740b9c git remote add kvm https://git.kernel.org/pub/scm/virt/kvm/kvm.git git fetch --no-tags kvm queue git checkout 3bd33d3f648e99bdf93f327f2abc40962d740b9c # 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 All warnings (new ones prefixed by >>): >> arch/x86/kvm/x86.c:5646:7: warning: variable 'r' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kvm/x86.c:5660:9: note: uninitialized use occurs here return r; ^ arch/x86/kvm/x86.c:5646:3: note: remove the 'if' if its condition is always true if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kvm/x86.c:5537:7: note: initialize the variable 'r' to silence this warning int r; ^ = 0 1 warning generated. vim +5646 arch/x86/kvm/x86.c 23d43cf998275b Christoffer Dall 2012-07-24 5533 e5d83c74a5800c Paolo Bonzini 2017-02-16 5534 int kvm_vm_ioctl_enable_cap(struct kvm *kvm, 90de4a1875180f Nadav Amit 2015-04-13 5535 struct kvm_enable_cap *cap) 90de4a1875180f Nadav Amit 2015-04-13 5536 { 90de4a1875180f Nadav Amit 2015-04-13 5537 int r; 90de4a1875180f Nadav Amit 2015-04-13 5538 90de4a1875180f Nadav Amit 2015-04-13 5539 if (cap->flags) 90de4a1875180f Nadav Amit 2015-04-13 5540 return -EINVAL; 90de4a1875180f Nadav Amit 2015-04-13 5541 90de4a1875180f Nadav Amit 2015-04-13 5542 switch (cap->cap) { 90de4a1875180f Nadav Amit 2015-04-13 5543 case KVM_CAP_DISABLE_QUIRKS: 90de4a1875180f Nadav Amit 2015-04-13 5544 kvm->arch.disabled_quirks = cap->args[0]; 90de4a1875180f Nadav Amit 2015-04-13 5545 r = 0; 90de4a1875180f Nadav Amit 2015-04-13 5546 break; 49df6397edfc5a Steve Rutherford 2015-07-29 5547 case KVM_CAP_SPLIT_IRQCHIP: { 49df6397edfc5a Steve Rutherford 2015-07-29 5548 mutex_lock(&kvm->lock); b053b2aef25d00 Steve Rutherford 2015-07-29 5549 r = -EINVAL; b053b2aef25d00 Steve Rutherford 2015-07-29 5550 if (cap->args[0] > MAX_NR_RESERVED_IOAPIC_PINS) b053b2aef25d00 Steve Rutherford 2015-07-29 5551 goto split_irqchip_unlock; 49df6397edfc5a Steve Rutherford 2015-07-29 5552 r = -EEXIST; 49df6397edfc5a Steve Rutherford 2015-07-29 5553 if (irqchip_in_kernel(kvm)) 49df6397edfc5a Steve Rutherford 2015-07-29 5554 goto split_irqchip_unlock; 557abc40d12135 Paolo Bonzini 2016-06-13 5555 if (kvm->created_vcpus) 49df6397edfc5a Steve Rutherford 2015-07-29 5556 goto split_irqchip_unlock; 49df6397edfc5a Steve Rutherford 2015-07-29 5557 r = kvm_setup_empty_irq_routing(kvm); 5c0aea0e8d98e3 David Hildenbrand 2017-04-28 5558 if (r) 49df6397edfc5a Steve Rutherford 2015-07-29 5559 goto split_irqchip_unlock; 49df6397edfc5a Steve Rutherford 2015-07-29 5560 /* Pairs with irqchip_in_kernel. */ 49df6397edfc5a Steve Rutherford 2015-07-29 5561 smp_wmb(); 49776faf93f807 Radim Krčmář 2016-12-16 5562 kvm->arch.irqchip_mode = KVM_IRQCHIP_SPLIT; b053b2aef25d00 Steve Rutherford 2015-07-29 5563 kvm->arch.nr_reserved_ioapic_pins = cap->args[0]; 49df6397edfc5a Steve Rutherford 2015-07-29 5564 r = 0; 49df6397edfc5a Steve Rutherford 2015-07-29 5565 split_irqchip_unlock: 49df6397edfc5a Steve Rutherford 2015-07-29 5566 mutex_unlock(&kvm->lock); 49df6397edfc5a Steve Rutherford 2015-07-29 5567 break; 49df6397edfc5a Steve Rutherford 2015-07-29 5568 } 3713131345fbea Radim Krčmář 2016-07-12 5569 case KVM_CAP_X2APIC_API: 3713131345fbea Radim Krčmář 2016-07-12 5570 r = -EINVAL; 3713131345fbea Radim Krčmář 2016-07-12 5571 if (cap->args[0] & ~KVM_X2APIC_API_VALID_FLAGS) 3713131345fbea Radim Krčmář 2016-07-12 5572 break; 3713131345fbea Radim Krčmář 2016-07-12 5573 3713131345fbea Radim Krčmář 2016-07-12 5574 if (cap->args[0] & KVM_X2APIC_API_USE_32BIT_IDS) 3713131345fbea Radim Krčmář 2016-07-12 5575 kvm->arch.x2apic_format = true; c519265f2aa348 Radim Krčmář 2016-07-12 5576 if (cap->args[0] & KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK) c519265f2aa348 Radim Krčmář 2016-07-12 5577 kvm->arch.x2apic_broadcast_quirk_disabled = true; 3713131345fbea Radim Krčmář 2016-07-12 5578 3713131345fbea Radim Krčmář 2016-07-12 5579 r = 0; 3713131345fbea Radim Krčmář 2016-07-12 5580 break; 4d5422cea3b61f Wanpeng Li 2018-03-12 5581 case KVM_CAP_X86_DISABLE_EXITS: 4d5422cea3b61f Wanpeng Li 2018-03-12 5582 r = -EINVAL; 4d5422cea3b61f Wanpeng Li 2018-03-12 5583 if (cap->args[0] & ~KVM_X86_DISABLE_VALID_EXITS) 4d5422cea3b61f Wanpeng Li 2018-03-12 5584 break; 4d5422cea3b61f Wanpeng Li 2018-03-12 5585 4d5422cea3b61f Wanpeng Li 2018-03-12 5586 if ((cap->args[0] & KVM_X86_DISABLE_EXITS_MWAIT) && 4d5422cea3b61f Wanpeng Li 2018-03-12 5587 kvm_can_mwait_in_guest()) 4d5422cea3b61f Wanpeng Li 2018-03-12 5588 kvm->arch.mwait_in_guest = true; 766d3571d8e50d Michael S. Tsirkin 2018-06-08 5589 if (cap->args[0] & KVM_X86_DISABLE_EXITS_HLT) caa057a2cad647 Wanpeng Li 2018-03-12 5590 kvm->arch.hlt_in_guest = true; b31c114b82b2b5 Wanpeng Li 2018-03-12 5591 if (cap->args[0] & KVM_X86_DISABLE_EXITS_PAUSE) b31c114b82b2b5 Wanpeng Li 2018-03-12 5592 kvm->arch.pause_in_guest = true; b51700632e0e53 Wanpeng Li 2019-05-21 5593 if (cap->args[0] & KVM_X86_DISABLE_EXITS_CSTATE) b51700632e0e53 Wanpeng Li 2019-05-21 5594 kvm->arch.cstate_in_guest = true; 4d5422cea3b61f Wanpeng Li 2018-03-12 5595 r = 0; 4d5422cea3b61f Wanpeng Li 2018-03-12 5596 break; 6fbbde9a1969df Drew Schmitt 2018-08-20 5597 case KVM_CAP_MSR_PLATFORM_INFO: 6fbbde9a1969df Drew Schmitt 2018-08-20 5598 kvm->arch.guest_can_read_msr_platform_info = cap->args[0]; 6fbbde9a1969df Drew Schmitt 2018-08-20 5599 r = 0; c4f55198c7c2b8 Jim Mattson 2018-10-16 5600 break; c4f55198c7c2b8 Jim Mattson 2018-10-16 5601 case KVM_CAP_EXCEPTION_PAYLOAD: c4f55198c7c2b8 Jim Mattson 2018-10-16 5602 kvm->arch.exception_payload_enabled = cap->args[0]; c4f55198c7c2b8 Jim Mattson 2018-10-16 5603 r = 0; 6fbbde9a1969df Drew Schmitt 2018-08-20 5604 break; 1ae099540e8c7f Alexander Graf 2020-09-25 5605 case KVM_CAP_X86_USER_SPACE_MSR: 1ae099540e8c7f Alexander Graf 2020-09-25 5606 kvm->arch.user_space_msr_mask = cap->args[0]; 1ae099540e8c7f Alexander Graf 2020-09-25 5607 r = 0; 1ae099540e8c7f Alexander Graf 2020-09-25 5608 break; fe6b6bc802b400 Chenyi Qiang 2020-11-06 5609 case KVM_CAP_X86_BUS_LOCK_EXIT: fe6b6bc802b400 Chenyi Qiang 2020-11-06 5610 r = -EINVAL; fe6b6bc802b400 Chenyi Qiang 2020-11-06 5611 if (cap->args[0] & ~KVM_BUS_LOCK_DETECTION_VALID_MODE) fe6b6bc802b400 Chenyi Qiang 2020-11-06 5612 break; fe6b6bc802b400 Chenyi Qiang 2020-11-06 5613 fe6b6bc802b400 Chenyi Qiang 2020-11-06 5614 if ((cap->args[0] & KVM_BUS_LOCK_DETECTION_OFF) && fe6b6bc802b400 Chenyi Qiang 2020-11-06 5615 (cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT)) fe6b6bc802b400 Chenyi Qiang 2020-11-06 5616 break; fe6b6bc802b400 Chenyi Qiang 2020-11-06 5617 fe6b6bc802b400 Chenyi Qiang 2020-11-06 5618 if (kvm_has_bus_lock_exit && fe6b6bc802b400 Chenyi Qiang 2020-11-06 5619 cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT) fe6b6bc802b400 Chenyi Qiang 2020-11-06 5620 kvm->arch.bus_lock_detection_enabled = true; fe6b6bc802b400 Chenyi Qiang 2020-11-06 5621 r = 0; fe6b6bc802b400 Chenyi Qiang 2020-11-06 5622 break; fe7e948837f312 Sean Christopherson 2021-04-12 5623 #ifdef CONFIG_X86_SGX_KVM fe7e948837f312 Sean Christopherson 2021-04-12 5624 case KVM_CAP_SGX_ATTRIBUTE: { fe7e948837f312 Sean Christopherson 2021-04-12 5625 unsigned long allowed_attributes = 0; fe7e948837f312 Sean Christopherson 2021-04-12 5626 fe7e948837f312 Sean Christopherson 2021-04-12 5627 r = sgx_set_attribute(&allowed_attributes, cap->args[0]); fe7e948837f312 Sean Christopherson 2021-04-12 5628 if (r) fe7e948837f312 Sean Christopherson 2021-04-12 5629 break; fe7e948837f312 Sean Christopherson 2021-04-12 5630 fe7e948837f312 Sean Christopherson 2021-04-12 5631 /* KVM only supports the PROVISIONKEY privileged attribute. */ fe7e948837f312 Sean Christopherson 2021-04-12 5632 if ((allowed_attributes & SGX_ATTR_PROVISIONKEY) && fe7e948837f312 Sean Christopherson 2021-04-12 5633 !(allowed_attributes & ~SGX_ATTR_PROVISIONKEY)) fe7e948837f312 Sean Christopherson 2021-04-12 5634 kvm->arch.sgx_provisioning_allowed = true; fe7e948837f312 Sean Christopherson 2021-04-12 5635 else fe7e948837f312 Sean Christopherson 2021-04-12 5636 r = -EINVAL; fe7e948837f312 Sean Christopherson 2021-04-12 5637 break; fe7e948837f312 Sean Christopherson 2021-04-12 5638 } fe7e948837f312 Sean Christopherson 2021-04-12 5639 #endif 54526d1fd59338 Nathan Tempelman 2021-04-08 5640 case KVM_CAP_VM_COPY_ENC_CONTEXT_FROM: 54526d1fd59338 Nathan Tempelman 2021-04-08 5641 r = -EINVAL; 54526d1fd59338 Nathan Tempelman 2021-04-08 5642 if (kvm_x86_ops.vm_copy_enc_context_from) 54526d1fd59338 Nathan Tempelman 2021-04-08 5643 r = kvm_x86_ops.vm_copy_enc_context_from(kvm, cap->args[0]); 54526d1fd59338 Nathan Tempelman 2021-04-08 5644 return r; 0dbb1123043789 Ashish Kalra 2021-06-08 5645 case KVM_CAP_EXIT_HYPERCALL: 0dbb1123043789 Ashish Kalra 2021-06-08 @5646 if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) { 0dbb1123043789 Ashish Kalra 2021-06-08 5647 r = -EINVAL; 0dbb1123043789 Ashish Kalra 2021-06-08 5648 break; 0dbb1123043789 Ashish Kalra 2021-06-08 5649 } 0dbb1123043789 Ashish Kalra 2021-06-08 5650 kvm->arch.hypercall_exit_enabled = cap->args[0]; 3bd33d3f648e99 Aaron Lewis 2021-05-10 5651 break; 3bd33d3f648e99 Aaron Lewis 2021-05-10 5652 case KVM_CAP_EXIT_ON_EMULATION_FAILURE: 3bd33d3f648e99 Aaron Lewis 2021-05-10 5653 kvm->arch.exit_on_emulation_error = cap->args[0]; 0dbb1123043789 Ashish Kalra 2021-06-08 5654 r = 0; 0dbb1123043789 Ashish Kalra 2021-06-08 5655 break; 90de4a1875180f Nadav Amit 2015-04-13 5656 default: 90de4a1875180f Nadav Amit 2015-04-13 5657 r = -EINVAL; 90de4a1875180f Nadav Amit 2015-04-13 5658 break; 90de4a1875180f Nadav Amit 2015-04-13 5659 } 90de4a1875180f Nadav Amit 2015-04-13 5660 return r; 90de4a1875180f Nadav Amit 2015-04-13 5661 } 90de4a1875180f Nadav Amit 2015-04-13 5662 :::::: The code at line 5646 was first introduced by commit :::::: 0dbb11230437895f7cd6fc55da61cef011e997d8 KVM: X86: Introduce KVM_HC_MAP_GPA_RANGE hypercall :::::: TO: Ashish Kalra :::::: CC: Paolo Bonzini --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org