Hi Christoph, FYI, the error/warning still remains. tree: git://git.infradead.org/users/hch/block.git bvec-phys head: 1caceae1dbe2ae172c3df6aa09d8122e0cc6b9e3 commit: 89142b678be44d8b11844add9d2b511dcb66edd9 [23/30] vhost: use bvec_kmap_local in {get,put}u16_iotlb config: ia64-allmodconfig (attached as .config) compiler: ia64-linux-gcc (GCC) 9.3.0 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 git remote add hch-block git://git.infradead.org/users/hch/block.git git fetch --no-tags hch-block bvec-phys git checkout 89142b678be44d8b11844add9d2b511dcb66edd9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/vhost/vringh.c: In function 'getu16_iotlb': 1185 | kaddr = bvec_kmap_local(&iov); | ^~~~~ drivers/vhost/vringh.c:1185:2: note: each undeclared identifier is reported only once for each function it appears in drivers/vhost/vringh.c:1176:8: warning: unused variable 'from' [-Wunused-variable] 1176 | void *from; | ^~~~ drivers/vhost/vringh.c: In function 'putu16_iotlb': 1207 | kunmap_loal(kaddr); | ^~~~~~~~~~~ | kunmap_local cc1: some warnings being treated as errors vim +/kaddr +1185 drivers/vhost/vringh.c 1171 1172 static inline int getu16_iotlb(const struct vringh *vrh, 1173 u16 *val, const __virtio16 *p) 1174 { 1175 struct bio_vec iov; 1176 void *from; 1177 int ret; 1178 1179 /* Atomic read is needed for getu16 */ 1180 ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), 1181 &iov, 1, VHOST_MAP_RO); 1182 if (ret < 0) 1183 return ret; 1184 1186 *val = vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)kaddr)); 1187 kunmap_local(kaddr); 1188 1189 return 0; 1190 } 1191 1192 static inline int putu16_iotlb(const struct vringh *vrh, 1193 __virtio16 *p, u16 val) 1194 { 1195 struct bio_vec iov; 1196 void *kaddr; 1197 int ret; 1198 1199 /* Atomic write is needed for putu16 */ 1200 ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), 1201 &iov, 1, VHOST_MAP_WO); 1202 if (ret < 0) 1203 return ret; 1204 1205 kaddr = bvec_kmap_local(&iov); 1206 WRITE_ONCE(*(__virtio16 *)kaddr, cpu_to_vringh16(vrh, val)); 1208 1209 return 0; 1210 } 1211 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org