Hi Sean, I love your patch! Yet something to improve: [auto build test ERROR on 26291c54e111ff6ba87a164d85d4a4e134b7315c] url: https://github.com/0day-ci/linux/commits/Sean-Christopherson/x86-uaccess-CMPXCHG-KVM-bug-fixes/20220201-091001 base: 26291c54e111ff6ba87a164d85d4a4e134b7315c config: i386-randconfig-a002 (https://download.01.org/0day-ci/archive/20220201/202202011753.zksthphR-lkp@xxxxxxxxx/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 6b1e844b69f15bb7dffaf9365cd2b355d2eb7579) 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/5387711f4b49675e162ca30b05a3b2435326e5f9 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Sean-Christopherson/x86-uaccess-CMPXCHG-KVM-bug-fixes/20220201-091001 git checkout 5387711f4b49675e162ca30b05a3b2435326e5f9 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): >> arch/x86/kvm/x86.c:7213:7: error: invalid output size for constraint '+a' r = emulator_try_cmpxchg_user(u64, hva, old, new); ^ arch/x86/kvm/x86.c:7159:3: note: expanded from macro 'emulator_try_cmpxchg_user' (__try_cmpxchg_user((t *)(ptr), (t *)(old), *(t *)(new), efault ## t)) ^ arch/x86/include/asm/uaccess.h:629:11: note: expanded from macro '__try_cmpxchg_user' __ret = !unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label); \ ^ arch/x86/include/asm/uaccess.h:606:18: note: expanded from macro 'unsafe_try_cmpxchg_user' case 1: __ret = __try_cmpxchg_user_asm("b", "q", \ ^ arch/x86/include/asm/uaccess.h:467:22: note: expanded from macro '__try_cmpxchg_user_asm' [old] "+a" (__old) \ ^ >> arch/x86/kvm/x86.c:7213:7: error: invalid output size for constraint '+a' arch/x86/kvm/x86.c:7159:3: note: expanded from macro 'emulator_try_cmpxchg_user' (__try_cmpxchg_user((t *)(ptr), (t *)(old), *(t *)(new), efault ## t)) ^ arch/x86/include/asm/uaccess.h:629:11: note: expanded from macro '__try_cmpxchg_user' __ret = !unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label); \ ^ arch/x86/include/asm/uaccess.h:610:18: note: expanded from macro 'unsafe_try_cmpxchg_user' case 2: __ret = __try_cmpxchg_user_asm("w", "r", \ ^ arch/x86/include/asm/uaccess.h:467:22: note: expanded from macro '__try_cmpxchg_user_asm' [old] "+a" (__old) \ ^ >> arch/x86/kvm/x86.c:7213:7: error: invalid output size for constraint '+a' arch/x86/kvm/x86.c:7159:3: note: expanded from macro 'emulator_try_cmpxchg_user' (__try_cmpxchg_user((t *)(ptr), (t *)(old), *(t *)(new), efault ## t)) ^ arch/x86/include/asm/uaccess.h:629:11: note: expanded from macro '__try_cmpxchg_user' __ret = !unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label); \ ^ arch/x86/include/asm/uaccess.h:614:18: note: expanded from macro 'unsafe_try_cmpxchg_user' case 4: __ret = __try_cmpxchg_user_asm("l", "r", \ ^ arch/x86/include/asm/uaccess.h:467:22: note: expanded from macro '__try_cmpxchg_user_asm' [old] "+a" (__old) \ ^ 3 errors generated. vim +7213 arch/x86/kvm/x86.c 7157 7158 #define emulator_try_cmpxchg_user(t, ptr, old, new) \ 7159 (__try_cmpxchg_user((t *)(ptr), (t *)(old), *(t *)(new), efault ## t)) 7160 7161 static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, 7162 unsigned long addr, 7163 const void *old, 7164 const void *new, 7165 unsigned int bytes, 7166 struct x86_exception *exception) 7167 { 7168 struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); 7169 u64 page_line_mask; 7170 unsigned long hva; 7171 gpa_t gpa; 7172 int r; 7173 7174 /* guests cmpxchg8b have to be emulated atomically */ 7175 if (bytes > 8 || (bytes & (bytes - 1))) 7176 goto emul_write; 7177 7178 gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, NULL); 7179 7180 if (gpa == UNMAPPED_GVA || 7181 (gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE) 7182 goto emul_write; 7183 7184 /* 7185 * Emulate the atomic as a straight write to avoid #AC if SLD is 7186 * enabled in the host and the access splits a cache line. 7187 */ 7188 if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) 7189 page_line_mask = ~(cache_line_size() - 1); 7190 else 7191 page_line_mask = PAGE_MASK; 7192 7193 if (((gpa + bytes - 1) & page_line_mask) != (gpa & page_line_mask)) 7194 goto emul_write; 7195 7196 hva = kvm_vcpu_gfn_to_hva(vcpu, gpa_to_gfn(gpa)); 7197 if (kvm_is_error_hva(addr)) 7198 goto emul_write; 7199 7200 hva += offset_in_page(gpa); 7201 7202 switch (bytes) { 7203 case 1: 7204 r = emulator_try_cmpxchg_user(u8, hva, old, new); 7205 break; 7206 case 2: 7207 r = emulator_try_cmpxchg_user(u16, hva, old, new); 7208 break; 7209 case 4: 7210 r = emulator_try_cmpxchg_user(u32, hva, old, new); 7211 break; 7212 case 8: > 7213 r = emulator_try_cmpxchg_user(u64, hva, old, new); 7214 break; 7215 default: 7216 BUG(); 7217 } 7218 7219 if (r < 0) 7220 goto emul_write; 7221 if (r) 7222 return X86EMUL_CMPXCHG_FAILED; 7223 7224 kvm_page_track_write(vcpu, gpa, new, bytes); 7225 7226 return X86EMUL_CONTINUE; 7227 7228 emul_write: 7229 printk_once(KERN_WARNING "kvm: emulating exchange as write\n"); 7230 7231 return emulator_write_emulated(ctxt, addr, new, bytes, exception); 7232 } 7233 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
