Hi Paolo, I love your patch! Perhaps something to improve: [auto build test WARNING on kvm/queue] [also build test WARNING on mst-vhost/linux-next linus/master v6.1-rc2 next-20221028] [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/Paolo-Bonzini/KVM-x86-allow-compiling-out-SMM-support/20221028-005156 base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue patch link: https://lore.kernel.org/r/20221027164944.3031588-5-pbonzini%40redhat.com patch subject: [PATCH 04/10] KVM: x86: do not go through ctxt->ops when emulating rsm config: i386-allyesconfig compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/9842725ac4bb9443d9b94d8c67d5e55ca3f5ab2b git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Paolo-Bonzini/KVM-x86-allow-compiling-out-SMM-support/20221028-005156 git checkout 9842725ac4bb9443d9b94d8c67d5e55ca3f5ab2b # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kvm/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): arch/x86/kvm/smm.c: In function 'emulator_leave_smm': >> arch/x86/kvm/smm.c:503:33: warning: unused variable 'efer' [-Wunused-variable] 503 | unsigned long cr0, cr4, efer; | ^~~~ >> arch/x86/kvm/smm.c:503:28: warning: unused variable 'cr4' [-Wunused-variable] 503 | unsigned long cr0, cr4, efer; | ^~~ vim +/efer +503 arch/x86/kvm/smm.c e2881deb76e87c Paolo Bonzini 2022-10-27 499 e2881deb76e87c Paolo Bonzini 2022-10-27 500 int emulator_leave_smm(struct x86_emulate_ctxt *ctxt) e2881deb76e87c Paolo Bonzini 2022-10-27 501 { e2881deb76e87c Paolo Bonzini 2022-10-27 502 struct kvm_vcpu *vcpu = ctxt->vcpu; e2881deb76e87c Paolo Bonzini 2022-10-27 @503 unsigned long cr0, cr4, efer; e2881deb76e87c Paolo Bonzini 2022-10-27 504 char buf[512]; e2881deb76e87c Paolo Bonzini 2022-10-27 505 u64 smbase; e2881deb76e87c Paolo Bonzini 2022-10-27 506 int ret; e2881deb76e87c Paolo Bonzini 2022-10-27 507 9842725ac4bb94 Paolo Bonzini 2022-10-27 508 smbase = vcpu->arch.smbase; e2881deb76e87c Paolo Bonzini 2022-10-27 509 9842725ac4bb94 Paolo Bonzini 2022-10-27 510 ret = kvm_vcpu_read_guest(vcpu, smbase + 0xfe00, buf, sizeof(buf)); 9842725ac4bb94 Paolo Bonzini 2022-10-27 511 if (ret < 0) e2881deb76e87c Paolo Bonzini 2022-10-27 512 return X86EMUL_UNHANDLEABLE; e2881deb76e87c Paolo Bonzini 2022-10-27 513 9842725ac4bb94 Paolo Bonzini 2022-10-27 514 if ((vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK) == 0) 9842725ac4bb94 Paolo Bonzini 2022-10-27 515 static_call(kvm_x86_set_nmi_mask)(vcpu, false); e2881deb76e87c Paolo Bonzini 2022-10-27 516 e2881deb76e87c Paolo Bonzini 2022-10-27 517 kvm_smm_changed(vcpu, false); e2881deb76e87c Paolo Bonzini 2022-10-27 518 e2881deb76e87c Paolo Bonzini 2022-10-27 519 /* e2881deb76e87c Paolo Bonzini 2022-10-27 520 * Get back to real mode, to prepare a safe state in which to load e2881deb76e87c Paolo Bonzini 2022-10-27 521 * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU e2881deb76e87c Paolo Bonzini 2022-10-27 522 * supports long mode. e2881deb76e87c Paolo Bonzini 2022-10-27 523 */ 9842725ac4bb94 Paolo Bonzini 2022-10-27 524 #ifdef CONFIG_X86_64 9842725ac4bb94 Paolo Bonzini 2022-10-27 525 if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) { 9842725ac4bb94 Paolo Bonzini 2022-10-27 526 struct kvm_segment cs_desc; e2881deb76e87c Paolo Bonzini 2022-10-27 527 e2881deb76e87c Paolo Bonzini 2022-10-27 528 /* Zero CR4.PCIDE before CR0.PG. */ 9842725ac4bb94 Paolo Bonzini 2022-10-27 529 cr4 = kvm_read_cr4(vcpu); e2881deb76e87c Paolo Bonzini 2022-10-27 530 if (cr4 & X86_CR4_PCIDE) 9842725ac4bb94 Paolo Bonzini 2022-10-27 531 kvm_set_cr4(vcpu, cr4 & ~X86_CR4_PCIDE); e2881deb76e87c Paolo Bonzini 2022-10-27 532 e2881deb76e87c Paolo Bonzini 2022-10-27 533 /* A 32-bit code segment is required to clear EFER.LMA. */ e2881deb76e87c Paolo Bonzini 2022-10-27 534 memset(&cs_desc, 0, sizeof(cs_desc)); e2881deb76e87c Paolo Bonzini 2022-10-27 535 cs_desc.type = 0xb; 9842725ac4bb94 Paolo Bonzini 2022-10-27 536 cs_desc.s = cs_desc.g = cs_desc.present = 1; 9842725ac4bb94 Paolo Bonzini 2022-10-27 537 kvm_set_segment(vcpu, &cs_desc, VCPU_SREG_CS); e2881deb76e87c Paolo Bonzini 2022-10-27 538 } 9842725ac4bb94 Paolo Bonzini 2022-10-27 539 #endif e2881deb76e87c Paolo Bonzini 2022-10-27 540 e2881deb76e87c Paolo Bonzini 2022-10-27 541 /* For the 64-bit case, this will clear EFER.LMA. */ 9842725ac4bb94 Paolo Bonzini 2022-10-27 542 cr0 = kvm_read_cr0(vcpu); e2881deb76e87c Paolo Bonzini 2022-10-27 543 if (cr0 & X86_CR0_PE) 9842725ac4bb94 Paolo Bonzini 2022-10-27 544 kvm_set_cr0(vcpu, cr0 & ~(X86_CR0_PG | X86_CR0_PE)); e2881deb76e87c Paolo Bonzini 2022-10-27 545 -- 0-DAY CI Kernel Test Service https://01.org/lkp