Re: [PATCH v6 12/14] KVM: s390: Extend MEM_OP ioctl by storage key checked cmpxchg

kernel test robot
2023-01-28T09:30:34Z

Hi Janis,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kvm/queue]
[also build test ERROR on lwn/docs-next linus/master]
[cannot apply to kvms390/next kvm/linux-next]
[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/Janis-Schoetterl-Glausch/KVM-s390-selftest-memop-Pass-mop_desc-via-pointer/20230128-132603
base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link: https://lore.kernel.org/r/20230125212608.1860251-13-scgl%40linux.ibm.com
patch subject: [PATCH v6 12/14] KVM: s390: Extend MEM_OP ioctl by storage key checked cmpxchg
config: s390-allyesconfig (https://download.01.org/0day-ci/archive/20230128/202301281752.6gSopuWh-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 12.1.0
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/intel-lab-lkp/linux/commit/6e6b3d99b9978a70b148b989d46b039feda3a3c3
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Janis-Schoetterl-Glausch/KVM-s390-selftest-memop-Pass-mop_desc-via-pointer/20230128-132603
git checkout 6e6b3d99b9978a70b148b989d46b039feda3a3c3
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

arch/s390/kvm/gaccess.c: In function 'cmpxchg_guest_abs_with_key':
>> arch/s390/kvm/gaccess.c:1217:23: error: implicit declaration of function 'cmpxchg_user_key'; did you mean 'copy_to_user_key'? [-Werror=implicit-function-declaration]
1217 | ret = cmpxchg_user_key((u8 *)hva, &old, *old_addr, new, access_key);
| ^~~~~~~~~~~~~~~~
| copy_to_user_key
cc1: some warnings being treated as errors

vim +1217 arch/s390/kvm/gaccess.c

1163
1164 /**
1165 * cmpxchg_guest_abs_with_key() - Perform cmpxchg on guest absolute address.
1166 * @kvm: Virtual machine instance.
1167 * @gpa: Absolute guest address of the location to be changed.
1168 * @len: Operand length of the cmpxchg, required: 1 <= len <= 16. Providing a
1169 * non power of two will result in failure.
1170 * @old_addr: Pointer to old value. If the location at @gpa contains this value,
1171 * the exchange will succeed. After calling cmpxchg_guest_abs_with_key()
1172 * *@old_addr contains the value at @gpa before the attempt to
1173 * exchange the value.
1174 * @new: The value to place at @gpa.
1175 * @access_key: The access key to use for the guest access.
1176 * @success: output value indicating if an exchange occurred.
1177 *
1178 * Atomically exchange the value at @gpa by @new, if it contains *@old.
1179 * Honors storage keys.
1180 *
1181 * Return: * 0: successful exchange
1182 * * a program interruption code indicating the reason cmpxchg could
1183 * not be attempted
1184 * * -EINVAL: address misaligned or len not power of two
1185 * * -EAGAIN: transient failure (len 1 or 2)
1186 * * -EOPNOTSUPP: read-only memslot (should never occur)
1187 */
1188 int cmpxchg_guest_abs_with_key(struct kvm *kvm, gpa_t gpa, int len,
1189 __uint128_t *old_addr, __uint128_t new,
1190 u8 access_key, bool *success)
1191 {
1192 gfn_t gfn = gpa >> PAGE_SHIFT;
1193 struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1194 bool writable;
1195 hva_t hva;
1196 int ret;
1197
1198 if (!IS_ALIGNED(gpa, len))
1199 return -EINVAL;
1200
1201 hva = gfn_to_hva_memslot_prot(slot, gfn, &writable);
1202 if (kvm_is_error_hva(hva))
1203 return PGM_ADDRESSING;
1204 /*
1205 * Check if it's a read-only memslot, even though that cannot occur
1206 * since those are unsupported.
1207 * Don't try to actually handle that case.
1208 */
1209 if (!writable)
1210 return -EOPNOTSUPP;
1211
1212 hva += offset_in_page(gpa);
1213 switch (len) {
1214 case 1: {
1215 u8 old;
1216
> 1217 ret = cmpxchg_user_key((u8 *)hva, &old, *old_addr, new, access_key);
1218 *success = !ret && old == *old_addr;
1219 *old_addr = old;
1220 break;
1221 }
1222 case 2: {
1223 u16 old;
1224
1225 ret = cmpxchg_user_key((u16 *)hva, &old, *old_addr, new, access_key);
1226 *success = !ret && old == *old_addr;
1227 *old_addr = old;
1228 break;
1229 }
1230 case 4: {
1231 u32 old;
1232
1233 ret = cmpxchg_user_key((u32 *)hva, &old, *old_addr, new, access_key);
1234 *success = !ret && old == *old_addr;
1235 *old_addr = old;
1236 break;
1237 }
1238 case 8: {
1239 u64 old;
1240
1241 ret = cmpxchg_user_key((u64 *)hva, &old, *old_addr, new, access_key);
1242 *success = !ret && old == *old_addr;
1243 *old_addr = old;
1244 break;
1245 }
1246 case 16: {
1247 __uint128_t old;
1248
1249 ret = cmpxchg_user_key((__uint128_t *)hva, &old, *old_addr, new, access_key);
1250 *success = !ret && old == *old_addr;
1251 *old_addr = old;
1252 break;
1253 }
1254 default:
1255 return -EINVAL;
1256 }
1257 mark_page_dirty_in_slot(kvm, slot, gfn);
1258 /*
1259 * Assume that the fault is caused by protection, either key protection
1260 * or user page write protection.
1261 */
1262 if (ret == -EFAULT)
1263 ret = PGM_PROTECTION;
1264 return ret;
1265 }
1266

--
0-DAY CI Kernel Test Service