Hi Fuad, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on c500bee1c5b2f1d59b1081ac879d73268ab0ff17] url: https://github.com/0day-ci/linux/commits/Fuad-Tabba/KVM-arm64-Fixed-featu... base: c500bee1c5b2f1d59b1081ac879d73268ab0ff17 config: arm64-allyesconfig (attached as .config) compiler: aarch64-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://github.com/0day-ci/linux/commit/58bc1e79b35b3353db259b152a450671b... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Fuad-Tabba/KVM-arm64-Fixed-features-for-protected-VMs/20210817-161500 git checkout 58bc1e79b35b3353db259b152a450671bc0822b2 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 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 >>): 390 | int kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu) | ^~~~~~~~~~~~~~~~~~~~ 426 | int kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu) | ^~~~~~~~~~~~~~~~~~~~~~~~~ vim +/kvm_handle_pvm_sys64 +390 arch/arm64/kvm/hyp/nvhe/sys_regs.c 384 385 /* 386 * Handler for protected VM MSR, MRS or System instruction execution in AArch64. 387 * 388 * Return 1 if handled, or 0 if not. 389 */ 391 { 392 const struct sys_reg_desc *r; 393 struct sys_reg_params params; 394 unsigned long esr = kvm_vcpu_get_esr(vcpu); 395 int Rt = kvm_vcpu_sys_get_rt(vcpu); 396 397 params = esr_sys64_to_params(esr); 398 params.regval = vcpu_get_reg(vcpu, Rt); 399 400 r = find_reg(&params, pvm_sys_reg_descs, ARRAY_SIZE(pvm_sys_reg_descs)); 401 402 /* Undefined access (RESTRICTED). */ 403 if (r == NULL) { 404 inject_undef(vcpu); 405 return 1; 406 } 407 408 /* Handled by the host (HOST_HANDLED) */ 409 if (r->access == NULL) 410 return 0; 411 412 /* Handled by hyp: skip instruction if instructed to do so. */ 413 if (r->access(vcpu, &params, r)) 414 __kvm_skip_instr(vcpu); 415 416 vcpu_set_reg(vcpu, Rt, params.regval); 417 return 1; 418 } 419 420 /* 421 * Handler for protected VM restricted exceptions. 422 * 423 * Inject an undefined exception into the guest and return 1 to indicate that 424 * it was handled. 425 */ --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org