| Message ID | 1448872427-11623-1-git-send-email-mst@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 2015-11-30 at 10:34 +0200, Michael S. Tsirkin wrote: > We know vring num is a power of 2, so use & > to mask the high bits. [] > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c [] > @@ -1366,10 +1366,12 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, > /* Only get avail ring entries after they have been exposed by guest. */ > smp_rmb(); > > + } ? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Michael,
[auto build test ERROR on: v4.4-rc3]
[also build test ERROR on: next-20151127]
url: https://github.com/0day-ci/linux/commits/Michael-S-Tsirkin/vhost-replace-with-on-data-path/20151130-163704
config: s390-performance_defconfig (attached as .config)
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=s390
All errors (new ones prefixed by >>):
drivers/vhost/vhost.c: In function 'vhost_get_vq_desc':
drivers/vhost/vhost.c:1345:6: warning: unused variable 'ret' [-Wunused-variable]
int ret;
^
drivers/vhost/vhost.c:1344:13: warning: unused variable 'ring_head' [-Wunused-variable]
__virtio16 ring_head;
^
drivers/vhost/vhost.c:1341:24: warning: unused variable 'found' [-Wunused-variable]
unsigned int i, head, found = 0;
^
drivers/vhost/vhost.c:1341:18: warning: unused variable 'head' [-Wunused-variable]
unsigned int i, head, found = 0;
^
drivers/vhost/vhost.c:1341:15: warning: unused variable 'i' [-Wunused-variable]
unsigned int i, head, found = 0;
^
drivers/vhost/vhost.c:1340:20: warning: unused variable 'desc' [-Wunused-variable]
struct vring_desc desc;
^
drivers/vhost/vhost.c: At top level:
drivers/vhost/vhost.c:1373:2: error: expected identifier or '(' before 'if'
if (unlikely(__get_user(ring_head,
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/s390/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
>> arch/s390/include/asm/uaccess.h:250:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:166:42: note: in definition of macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
drivers/vhost/vhost.c:1381:2: warning: data definition has no type or storage class
head = vhost16_to_cpu(vq, ring_head);
^
drivers/vhost/vhost.c:1381:2: error: type defaults to 'int' in declaration of 'head' [-Werror=implicit-int]
drivers/vhost/vhost.c:1381:24: error: 'vq' undeclared here (not in a function)
head = vhost16_to_cpu(vq, ring_head);
^
drivers/vhost/vhost.c:1381:28: error: 'ring_head' undeclared here (not in a function)
head = vhost16_to_cpu(vq, ring_head);
^
drivers/vhost/vhost.c:1384:2: error: expected identifier or '(' before 'if'
if (unlikely(head >= vq->num)) {
^
drivers/vhost/vhost.c:1391:2: warning: data definition has no type or storage class
*out_num = *in_num = 0;
^
drivers/vhost/vhost.c:1391:3: error: type defaults to 'int' in declaration of 'out_num' [-Werror=implicit-int]
*out_num = *in_num = 0;
^
drivers/vhost/vhost.c:1391:14: error: 'in_num' undeclared here (not in a function)
*out_num = *in_num = 0;
^
drivers/vhost/vhost.c:1392:2: error: expected identifier or '(' before 'if'
if (unlikely(log))
^
drivers/vhost/vhost.c:1395:2: warning: data definition has no type or storage class
i = head;
^
drivers/vhost/vhost.c:1395:2: error: type defaults to 'int' in declaration of 'i' [-Werror=implicit-int]
drivers/vhost/vhost.c:1395:2: error: initializer element is not constant
drivers/vhost/vhost.c:1396:2: error: expected identifier or '(' before 'do'
do {
^
drivers/vhost/vhost.c:1454:4: error: expected identifier or '(' before 'while'
} while ((i = next_desc(vq, &desc)) != -1);
^
drivers/vhost/vhost.c:1457:4: error: expected '=', ',', ';', 'asm' or '__attribute__' before '->' token
vq->last_avail_idx++;
^
In file included from arch/s390/include/asm/bug.h:69:0,
from include/linux/bug.h:4,
from include/linux/thread_info.h:11,
from include/asm-generic/preempt.h:4,
from arch/s390/include/generated/asm/preempt.h:1,
from include/linux/preempt.h:59,
from include/linux/spinlock.h:50,
from include/linux/wait.h:8,
from include/linux/eventfd.h:12,
from drivers/vhost/vhost.c:14:
include/asm-generic/bug.h:55:27: error: expected identifier or '(' before 'do'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^
drivers/vhost/vhost.c:1461:2: note: in expansion of macro 'BUG_ON'
BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
^
include/asm-generic/bug.h:55:66: error: expected identifier or '(' before 'while'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^
drivers/vhost/vhost.c:1461:2: note: in expansion of macro 'BUG_ON'
BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
^
drivers/vhost/vhost.c:1462:2: error: expected identifier or '(' before 'return'
return head;
^
drivers/vhost/vhost.c:1463:1: error: expected identifier or '(' before '}' token
}
^
drivers/vhost/vhost.c:1235:12: warning: 'get_indirect' defined but not used [-Wunused-function]
static int get_indirect(struct vhost_virtqueue *vq,
^
drivers/vhost/vhost.c: In function 'vhost_get_vq_desc':
drivers/vhost/vhost.c:1369:2: warning: control reaches end of non-void function [-Wreturn-type]
}
^
cc1: some warnings being treated as errors
vim +250 arch/s390/include/asm/uaccess.h
cfa785e62 arch/s390/include/asm/uaccess.h Heiko Carstens 2014-01-22 234 sizeof(*(ptr))); \
97fa5a664 include/asm-s390/uaccess.h Al Viro 2006-02-03 235 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
1047aa772 include/asm-s390/uaccess.h Martin Schwidefsky 2005-11-07 236 break; \
1047aa772 include/asm-s390/uaccess.h Martin Schwidefsky 2005-11-07 237 }; \
1047aa772 include/asm-s390/uaccess.h Martin Schwidefsky 2005-11-07 238 case 8: { \
1047aa772 include/asm-s390/uaccess.h Martin Schwidefsky 2005-11-07 239 unsigned long long __x; \
cfa785e62 arch/s390/include/asm/uaccess.h Heiko Carstens 2014-01-22 240 __gu_err = __get_user_fn(&__x, ptr, \
cfa785e62 arch/s390/include/asm/uaccess.h Heiko Carstens 2014-01-22 241 sizeof(*(ptr))); \
97fa5a664 include/asm-s390/uaccess.h Al Viro 2006-02-03 242 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 243 break; \
1047aa772 include/asm-s390/uaccess.h Martin Schwidefsky 2005-11-07 244 }; \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 245 default: \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 246 __get_user_bad(); \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 247 break; \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 248 } \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 249 __gu_err; \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 @250 })
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 251
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 252 #define get_user(x, ptr) \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 253 ({ \
dab4079d5 arch/s390/include/asm/uaccess.h Heiko Carstens 2009-06-12 254 might_fault(); \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 255 __get_user(x, ptr); \
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 256 })
^1da177e4 include/asm-s390/uaccess.h Linus Torvalds 2005-04-16 257
4f41c2b45 arch/s390/include/asm/uaccess.h Heiko Carstens 2014-01-23 258 int __get_user_bad(void) __attribute__((noreturn));
:::::: The code at line 250 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2
:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Michael,
[auto build test ERROR on: v4.4-rc3]
[also build test ERROR on: next-20151127]
url: https://github.com/0day-ci/linux/commits/Michael-S-Tsirkin/vhost-replace-with-on-data-path/20151130-163704
config: i386-randconfig-s1-201548 (attached as .config)
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All error/warnings (new ones prefixed by >>):
drivers/vhost/vhost.c: In function 'vhost_get_vq_desc':
>> drivers/vhost/vhost.c:1345:6: warning: unused variable 'ret' [-Wunused-variable]
int ret;
^
>> drivers/vhost/vhost.c:1344:13: warning: unused variable 'ring_head' [-Wunused-variable]
__virtio16 ring_head;
^
>> drivers/vhost/vhost.c:1341:24: warning: unused variable 'found' [-Wunused-variable]
unsigned int i, head, found = 0;
^
>> drivers/vhost/vhost.c:1341:18: warning: unused variable 'head' [-Wunused-variable]
unsigned int i, head, found = 0;
^
>> drivers/vhost/vhost.c:1341:15: warning: unused variable 'i' [-Wunused-variable]
unsigned int i, head, found = 0;
^
>> drivers/vhost/vhost.c:1340:20: warning: unused variable 'desc' [-Wunused-variable]
struct vring_desc desc;
^
drivers/vhost/vhost.c: At top level:
>> drivers/vhost/vhost.c:1373:2: error: expected identifier or '(' before 'if'
if (unlikely(__get_user(ring_head,
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/x86/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
>> arch/x86/include/asm/uaccess.h:414:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:137:45: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
arch/x86/include/asm/uaccess.h:479:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
^
>> drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
>> arch/x86/include/asm/uaccess.h:414:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:137:53: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
arch/x86/include/asm/uaccess.h:479:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
^
>> drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
>> include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
>> drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
>> drivers/vhost/vhost.c:1381:2: warning: data definition has no type or storage class
head = vhost16_to_cpu(vq, ring_head);
^
>> drivers/vhost/vhost.c:1381:2: error: type defaults to 'int' in declaration of 'head' [-Werror=implicit-int]
>> drivers/vhost/vhost.c:1381:24: error: 'vq' undeclared here (not in a function)
head = vhost16_to_cpu(vq, ring_head);
^
>> drivers/vhost/vhost.c:1381:28: error: 'ring_head' undeclared here (not in a function)
head = vhost16_to_cpu(vq, ring_head);
^
drivers/vhost/vhost.c:1384:2: error: expected identifier or '(' before 'if'
if (unlikely(head >= vq->num)) {
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/x86/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
>> include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1384:6: note: in expansion of macro 'unlikely'
if (unlikely(head >= vq->num)) {
^
drivers/vhost/vhost.c:1391:2: warning: data definition has no type or storage class
*out_num = *in_num = 0;
^
>> drivers/vhost/vhost.c:1391:3: error: type defaults to 'int' in declaration of 'out_num' [-Werror=implicit-int]
*out_num = *in_num = 0;
^
>> drivers/vhost/vhost.c:1391:14: error: 'in_num' undeclared here (not in a function)
*out_num = *in_num = 0;
^
drivers/vhost/vhost.c:1392:2: error: expected identifier or '(' before 'if'
if (unlikely(log))
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/x86/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
vim +1373 drivers/vhost/vhost.c
d5675bd2 Michael S. Tsirkin 2010-06-24 1334 * returned on error. */
47283bef Michael S. Tsirkin 2014-06-05 1335 int vhost_get_vq_desc(struct vhost_virtqueue *vq,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1336 struct iovec iov[], unsigned int iov_size,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1337 unsigned int *out_num, unsigned int *in_num,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1338 struct vhost_log *log, unsigned int *log_num)
3a4d5c94 Michael S. Tsirkin 2010-01-14 1339 {
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1340 struct vring_desc desc;
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1341 unsigned int i, head, found = 0;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1342 u16 last_avail_idx;
3b1bbe89 Michael S. Tsirkin 2014-10-24 1343 __virtio16 avail_idx;
3b1bbe89 Michael S. Tsirkin 2014-10-24 @1344 __virtio16 ring_head;
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1345 int ret;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1346
3a4d5c94 Michael S. Tsirkin 2010-01-14 1347 /* Check it isn't doing very strange things with descriptor numbers. */
3a4d5c94 Michael S. Tsirkin 2010-01-14 1348 last_avail_idx = vq->last_avail_idx;
3b1bbe89 Michael S. Tsirkin 2014-10-24 1349 if (unlikely(__get_user(avail_idx, &vq->avail->idx))) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1350 vq_err(vq, "Failed to access avail idx at %p\n",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1351 &vq->avail->idx);
d5675bd2 Michael S. Tsirkin 2010-06-24 1352 return -EFAULT;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1353 }
3b1bbe89 Michael S. Tsirkin 2014-10-24 1354 vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
3a4d5c94 Michael S. Tsirkin 2010-01-14 1355
7b3384fc Michael S. Tsirkin 2010-07-01 1356 if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1357 vq_err(vq, "Guest moved used index from %u to %u",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1358 last_avail_idx, vq->avail_idx);
d5675bd2 Michael S. Tsirkin 2010-06-24 1359 return -EFAULT;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1360 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1361
3a4d5c94 Michael S. Tsirkin 2010-01-14 1362 /* If there's nothing new since last we looked, return invalid. */
3a4d5c94 Michael S. Tsirkin 2010-01-14 1363 if (vq->avail_idx == last_avail_idx)
3a4d5c94 Michael S. Tsirkin 2010-01-14 1364 return vq->num;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1365
3a4d5c94 Michael S. Tsirkin 2010-01-14 1366 /* Only get avail ring entries after they have been exposed by guest. */
5659338c Michael S. Tsirkin 2010-02-01 1367 smp_rmb();
3a4d5c94 Michael S. Tsirkin 2010-01-14 1368
07a08023 Michael S. Tsirkin 2015-11-30 @1369 }
07a08023 Michael S. Tsirkin 2015-11-30 1370
3a4d5c94 Michael S. Tsirkin 2010-01-14 1371 /* Grab the next descriptor number they're advertising, and increment
3a4d5c94 Michael S. Tsirkin 2010-01-14 1372 * the index we've seen. */
3b1bbe89 Michael S. Tsirkin 2014-10-24 @1373 if (unlikely(__get_user(ring_head,
07a08023 Michael S. Tsirkin 2015-11-30 1374 &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1375 vq_err(vq, "Failed to read head: idx %d address %p\n",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1376 last_avail_idx,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1377 &vq->avail->ring[last_avail_idx % vq->num]);
d5675bd2 Michael S. Tsirkin 2010-06-24 1378 return -EFAULT;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1379 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1380
3b1bbe89 Michael S. Tsirkin 2014-10-24 @1381 head = vhost16_to_cpu(vq, ring_head);
3b1bbe89 Michael S. Tsirkin 2014-10-24 1382
3a4d5c94 Michael S. Tsirkin 2010-01-14 1383 /* If their number is silly, that's an error. */
7b3384fc Michael S. Tsirkin 2010-07-01 @1384 if (unlikely(head >= vq->num)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1385 vq_err(vq, "Guest says index %u > %u is available",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1386 head, vq->num);
d5675bd2 Michael S. Tsirkin 2010-06-24 1387 return -EINVAL;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1388 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1389
3a4d5c94 Michael S. Tsirkin 2010-01-14 1390 /* When we start there are none of either input nor output. */
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1391 *out_num = *in_num = 0;
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1392 if (unlikely(log))
3a4d5c94 Michael S. Tsirkin 2010-01-14 1393 *log_num = 0;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1394
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1395 i = head;
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1396 do {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1397 unsigned iov_count = *in_num + *out_num;
7b3384fc Michael S. Tsirkin 2010-07-01 1398 if (unlikely(i >= vq->num)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1399 vq_err(vq, "Desc index is %u > %u, head = %u",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1400 i, vq->num, head);
d5675bd2 Michael S. Tsirkin 2010-06-24 1401 return -EINVAL;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1402 }
7b3384fc Michael S. Tsirkin 2010-07-01 1403 if (unlikely(++found > vq->num)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1404 vq_err(vq, "Loop detected: last one at %u "
3a4d5c94 Michael S. Tsirkin 2010-01-14 1405 "vq size %u head %u\n",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1406 i, vq->num, head);
d5675bd2 Michael S. Tsirkin 2010-06-24 1407 return -EINVAL;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1408 }
fcc042a2 Michael S. Tsirkin 2011-03-06 1409 ret = __copy_from_user(&desc, vq->desc + i, sizeof desc);
7b3384fc Michael S. Tsirkin 2010-07-01 1410 if (unlikely(ret)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1411 vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1412 i, vq->desc + i);
d5675bd2 Michael S. Tsirkin 2010-06-24 1413 return -EFAULT;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1414 }
3b1bbe89 Michael S. Tsirkin 2014-10-24 1415 if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {
47283bef Michael S. Tsirkin 2014-06-05 1416 ret = get_indirect(vq, iov, iov_size,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1417 out_num, in_num,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1418 log, log_num, &desc);
7b3384fc Michael S. Tsirkin 2010-07-01 1419 if (unlikely(ret < 0)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1420 vq_err(vq, "Failure detected "
3a4d5c94 Michael S. Tsirkin 2010-01-14 1421 "in indirect descriptor at idx %d\n", i);
d5675bd2 Michael S. Tsirkin 2010-06-24 1422 return ret;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1423 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1424 continue;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1425 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1426
3b1bbe89 Michael S. Tsirkin 2014-10-24 1427 ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
3b1bbe89 Michael S. Tsirkin 2014-10-24 1428 vhost32_to_cpu(vq, desc.len), iov + iov_count,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1429 iov_size - iov_count);
7b3384fc Michael S. Tsirkin 2010-07-01 1430 if (unlikely(ret < 0)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1431 vq_err(vq, "Translation failure %d descriptor idx %d\n",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1432 ret, i);
d5675bd2 Michael S. Tsirkin 2010-06-24 1433 return ret;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1434 }
3b1bbe89 Michael S. Tsirkin 2014-10-24 1435 if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1436 /* If this is an input descriptor,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1437 * increment that count. */
3a4d5c94 Michael S. Tsirkin 2010-01-14 1438 *in_num += ret;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1439 if (unlikely(log)) {
3b1bbe89 Michael S. Tsirkin 2014-10-24 1440 log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
3b1bbe89 Michael S. Tsirkin 2014-10-24 1441 log[*log_num].len = vhost32_to_cpu(vq, desc.len);
3a4d5c94 Michael S. Tsirkin 2010-01-14 1442 ++*log_num;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1443 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1444 } else {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1445 /* If it's an output descriptor, they're all supposed
3a4d5c94 Michael S. Tsirkin 2010-01-14 1446 * to come before any input descriptors. */
7b3384fc Michael S. Tsirkin 2010-07-01 1447 if (unlikely(*in_num)) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1448 vq_err(vq, "Descriptor has out after in: "
3a4d5c94 Michael S. Tsirkin 2010-01-14 1449 "idx %d\n", i);
d5675bd2 Michael S. Tsirkin 2010-06-24 1450 return -EINVAL;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1451 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1452 *out_num += ret;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1453 }
3b1bbe89 Michael S. Tsirkin 2014-10-24 @1454 } while ((i = next_desc(vq, &desc)) != -1);
3a4d5c94 Michael S. Tsirkin 2010-01-14 1455
3a4d5c94 Michael S. Tsirkin 2010-01-14 1456 /* On success, increment avail index. */
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1457 vq->last_avail_idx++;
8ea8cf89 Michael S. Tsirkin 2011-05-20 1458
8ea8cf89 Michael S. Tsirkin 2011-05-20 1459 /* Assume notifications from guest are disabled at this point,
8ea8cf89 Michael S. Tsirkin 2011-05-20 1460 * if they aren't we would need to update avail_event index. */
8ea8cf89 Michael S. Tsirkin 2011-05-20 @1461 BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1462 return head;
3a4d5c94 Michael S. Tsirkin 2010-01-14 @1463 }
6ac1afbf Asias He 2013-05-06 1464 EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
3a4d5c94 Michael S. Tsirkin 2010-01-14 1465
3a4d5c94 Michael S. Tsirkin 2010-01-14 1466 /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
:::::: The code at line 1373 was first introduced by commit
:::::: 3b1bbe89351a8003857aeb5cbef3595f5d0ee609 vhost: virtio 1.0 endian-ness support
:::::: TO: Michael S. Tsirkin <mst@redhat.com>
:::::: CC: Michael S. Tsirkin <mst@redhat.com>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Mon, Nov 30, 2015 at 10:34:07AM +0200, Michael S. Tsirkin wrote: > We know vring num is a power of 2, so use & > to mask the high bits. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/vhost/vhost.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 080422f..85f0f0a 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -1366,10 +1366,12 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, > /* Only get avail ring entries after they have been exposed by guest. */ > smp_rmb(); > > + } > + Oops. This sneaked in from an unrelated patch. Pls ignore, will repost. > /* Grab the next descriptor number they're advertising, and increment > * the index we've seen. */ > if (unlikely(__get_user(ring_head, > - &vq->avail->ring[last_avail_idx % vq->num]))) { > + &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) { > vq_err(vq, "Failed to read head: idx %d address %p\n", > last_avail_idx, > &vq->avail->ring[last_avail_idx % vq->num]); > @@ -1489,7 +1491,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq, > u16 old, new; > int start; > > - start = vq->last_used_idx % vq->num; > + start = vq->last_used_idx & (vq->num - 1); > used = vq->used->ring + start; > if (count == 1) { > if (__put_user(heads[0].id, &used->id)) { > @@ -1531,7 +1533,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, > { > int start, n, r; > > - start = vq->last_used_idx % vq->num; > + start = vq->last_used_idx & (vq->num - 1); > n = vq->num - start; > if (n < count) { > r = __vhost_add_used_n(vq, heads, n); > -- > MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Michael,
[auto build test ERROR on: v4.4-rc3]
[also build test ERROR on: next-20151127]
url: https://github.com/0day-ci/linux/commits/Michael-S-Tsirkin/vhost-replace-with-on-data-path/20151130-163704
config: x86_64-randconfig-s0-11301655 (attached as .config)
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All error/warnings (new ones prefixed by >>):
drivers/vhost/vhost.c: In function 'vhost_get_vq_desc':
drivers/vhost/vhost.c:1345:6: warning: unused variable 'ret' [-Wunused-variable]
int ret;
^
drivers/vhost/vhost.c:1344:13: warning: unused variable 'ring_head' [-Wunused-variable]
__virtio16 ring_head;
^
drivers/vhost/vhost.c:1341:24: warning: unused variable 'found' [-Wunused-variable]
unsigned int i, head, found = 0;
^
drivers/vhost/vhost.c:1341:18: warning: unused variable 'head' [-Wunused-variable]
unsigned int i, head, found = 0;
^
drivers/vhost/vhost.c:1341:15: warning: unused variable 'i' [-Wunused-variable]
unsigned int i, head, found = 0;
^
drivers/vhost/vhost.c:1340:20: warning: unused variable 'desc' [-Wunused-variable]
struct vring_desc desc;
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/x86/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
drivers/vhost/vhost.c: At top level:
>> include/linux/compiler.h:147:2: error: expected identifier or '(' before 'if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
include/linux/compiler.h:145:23: note: in expansion of macro '__trace_if'
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:414:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:28: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:479:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
^
drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:414:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:28: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:479:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
^
drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:28: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:414:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:40: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:479:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
^
drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:414:2: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:40: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
arch/x86/include/asm/uaccess.h:479:2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
^
drivers/vhost/vhost.c:1373:15: note: in expansion of macro '__get_user'
if (unlikely(__get_user(ring_head,
^
include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:40: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1373:6: note: in expansion of macro 'unlikely'
if (unlikely(__get_user(ring_head,
^
include/linux/compiler.h:161:3: error: expected identifier or '(' before ')' token
}))
^
include/linux/compiler.h:145:23: note: in expansion of macro '__trace_if'
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
^
>> drivers/vhost/vhost.c:1373:2: note: in expansion of macro 'if'
if (unlikely(__get_user(ring_head,
^
drivers/vhost/vhost.c:1381:2: warning: data definition has no type or storage class
head = vhost16_to_cpu(vq, ring_head);
^
drivers/vhost/vhost.c:1381:2: error: type defaults to 'int' in declaration of 'head' [-Werror=implicit-int]
drivers/vhost/vhost.c:1381:24: error: 'vq' undeclared here (not in a function)
head = vhost16_to_cpu(vq, ring_head);
^
drivers/vhost/vhost.c:1381:28: error: 'ring_head' undeclared here (not in a function)
head = vhost16_to_cpu(vq, ring_head);
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/x86/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
>> include/linux/compiler.h:147:2: error: expected identifier or '(' before 'if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
include/linux/compiler.h:145:23: note: in expansion of macro '__trace_if'
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
^
drivers/vhost/vhost.c:1384:2: note: in expansion of macro 'if'
if (unlikely(head >= vq->num)) {
^
include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:28: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
drivers/vhost/vhost.c:1384:2: note: in expansion of macro 'if'
if (unlikely(head >= vq->num)) {
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1384:6: note: in expansion of macro 'unlikely'
if (unlikely(head >= vq->num)) {
^
include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:40: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
drivers/vhost/vhost.c:1384:2: note: in expansion of macro 'if'
if (unlikely(head >= vq->num)) {
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1384:6: note: in expansion of macro 'unlikely'
if (unlikely(head >= vq->num)) {
^
include/linux/compiler.h:161:3: error: expected identifier or '(' before ')' token
}))
^
include/linux/compiler.h:145:23: note: in expansion of macro '__trace_if'
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
^
drivers/vhost/vhost.c:1384:2: note: in expansion of macro 'if'
if (unlikely(head >= vq->num)) {
^
drivers/vhost/vhost.c:1391:2: warning: data definition has no type or storage class
*out_num = *in_num = 0;
^
drivers/vhost/vhost.c:1391:3: error: type defaults to 'int' in declaration of 'out_num' [-Werror=implicit-int]
*out_num = *in_num = 0;
^
drivers/vhost/vhost.c:1391:14: error: 'in_num' undeclared here (not in a function)
*out_num = *in_num = 0;
^
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/asm-generic/fcntl.h:4,
from arch/x86/include/uapi/asm/fcntl.h:1,
from include/uapi/linux/fcntl.h:4,
from include/linux/fcntl.h:4,
from include/linux/eventfd.h:11,
from drivers/vhost/vhost.c:14:
>> include/linux/compiler.h:147:2: error: expected identifier or '(' before 'if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
include/linux/compiler.h:145:23: note: in expansion of macro '__trace_if'
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
^
drivers/vhost/vhost.c:1392:2: note: in expansion of macro 'if'
if (unlikely(log))
^
include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:28: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
drivers/vhost/vhost.c:1392:2: note: in expansion of macro 'if'
if (unlikely(log))
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1392:6: note: in expansion of macro 'unlikely'
if (unlikely(log))
^
include/linux/compiler.h:126:4: error: expected identifier or '(' before ')' token
})
^
include/linux/compiler.h:147:40: note: in definition of macro '__trace_if'
if (__builtin_constant_p((cond)) ? !!(cond) : \
^
drivers/vhost/vhost.c:1392:2: note: in expansion of macro 'if'
if (unlikely(log))
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/vhost/vhost.c:1392:6: note: in expansion of macro 'unlikely'
if (unlikely(log))
^
include/linux/compiler.h:161:3: error: expected identifier or '(' before ')' token
}))
^
include/linux/compiler.h:145:23: note: in expansion of macro '__trace_if'
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
^
drivers/vhost/vhost.c:1392:2: note: in expansion of macro 'if'
if (unlikely(log))
^
drivers/vhost/vhost.c:1395:2: warning: data definition has no type or storage class
i = head;
^
drivers/vhost/vhost.c:1395:2: error: type defaults to 'int' in declaration of 'i' [-Werror=implicit-int]
drivers/vhost/vhost.c:1395:6: error: initializer element is not constant
i = head;
^
drivers/vhost/vhost.c:1396:2: error: expected identifier or '(' before 'do'
do {
^
drivers/vhost/vhost.c:1454:4: error: expected identifier or '(' before 'while'
} while ((i = next_desc(vq, &desc)) != -1);
^
drivers/vhost/vhost.c:1457:4: error: expected '=', ',', ';', 'asm' or '__attribute__' before '->' token
vq->last_avail_idx++;
^
In file included from arch/x86/include/asm/bug.h:35:0,
from include/linux/bug.h:4,
from include/linux/thread_info.h:11,
from arch/x86/include/asm/preempt.h:6,
from include/linux/preempt.h:59,
from include/linux/spinlock.h:50,
from include/linux/wait.h:8,
from include/linux/eventfd.h:12,
from drivers/vhost/vhost.c:14:
include/asm-generic/bug.h:55:27: error: expected identifier or '(' before 'do'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^
drivers/vhost/vhost.c:1461:2: note: in expansion of macro 'BUG_ON'
BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
^
include/asm-generic/bug.h:55:66: error: expected identifier or '(' before 'while'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^
drivers/vhost/vhost.c:1461:2: note: in expansion of macro 'BUG_ON'
BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
^
drivers/vhost/vhost.c:1462:2: error: expected identifier or '(' before 'return'
return head;
^
drivers/vhost/vhost.c:1463:1: error: expected identifier or '(' before '}' token
}
^
drivers/vhost/vhost.c:1235:12: warning: 'get_indirect' defined but not used [-Wunused-function]
static int get_indirect(struct vhost_virtqueue *vq,
^
drivers/vhost/vhost.c: In function 'vhost_get_vq_desc':
drivers/vhost/vhost.c:1369:2: warning: control reaches end of non-void function [-Wreturn-type]
}
^
cc1: some warnings being treated as errors
vim +/if +1373 drivers/vhost/vhost.c
3a4d5c94 Michael S. Tsirkin 2010-01-14 1357 vq_err(vq, "Guest moved used index from %u to %u",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1358 last_avail_idx, vq->avail_idx);
d5675bd2 Michael S. Tsirkin 2010-06-24 1359 return -EFAULT;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1360 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1361
3a4d5c94 Michael S. Tsirkin 2010-01-14 1362 /* If there's nothing new since last we looked, return invalid. */
3a4d5c94 Michael S. Tsirkin 2010-01-14 1363 if (vq->avail_idx == last_avail_idx)
3a4d5c94 Michael S. Tsirkin 2010-01-14 1364 return vq->num;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1365
3a4d5c94 Michael S. Tsirkin 2010-01-14 1366 /* Only get avail ring entries after they have been exposed by guest. */
5659338c Michael S. Tsirkin 2010-02-01 1367 smp_rmb();
3a4d5c94 Michael S. Tsirkin 2010-01-14 1368
07a08023 Michael S. Tsirkin 2015-11-30 1369 }
07a08023 Michael S. Tsirkin 2015-11-30 1370
3a4d5c94 Michael S. Tsirkin 2010-01-14 1371 /* Grab the next descriptor number they're advertising, and increment
3a4d5c94 Michael S. Tsirkin 2010-01-14 1372 * the index we've seen. */
3b1bbe89 Michael S. Tsirkin 2014-10-24 @1373 if (unlikely(__get_user(ring_head,
07a08023 Michael S. Tsirkin 2015-11-30 1374 &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {
3a4d5c94 Michael S. Tsirkin 2010-01-14 1375 vq_err(vq, "Failed to read head: idx %d address %p\n",
3a4d5c94 Michael S. Tsirkin 2010-01-14 1376 last_avail_idx,
3a4d5c94 Michael S. Tsirkin 2010-01-14 1377 &vq->avail->ring[last_avail_idx % vq->num]);
d5675bd2 Michael S. Tsirkin 2010-06-24 1378 return -EFAULT;
3a4d5c94 Michael S. Tsirkin 2010-01-14 1379 }
3a4d5c94 Michael S. Tsirkin 2010-01-14 1380
3b1bbe89 Michael S. Tsirkin 2014-10-24 1381 head = vhost16_to_cpu(vq, ring_head);
:::::: The code at line 1373 was first introduced by commit
:::::: 3b1bbe89351a8003857aeb5cbef3595f5d0ee609 vhost: virtio 1.0 endian-ness support
:::::: TO: Michael S. Tsirkin <mst@redhat.com>
:::::: CC: Michael S. Tsirkin <mst@redhat.com>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Mon, Nov 30, 2015 at 12:42:49AM -0800, Joe Perches wrote: > On Mon, 2015-11-30 at 10:34 +0200, Michael S. Tsirkin wrote: > > We know vring num is a power of 2, so use & > > to mask the high bits. > [] > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > [] > > @@ -1366,10 +1366,12 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, > > /* Only get avail ring entries after they have been exposed by guest. */ > > smp_rmb(); > > > > + } > > ? Yes, I noticed this - I moved this chunk from the next patch in my tree by mistake. Will fix, thanks!
From: "Michael S. Tsirkin" <mst@redhat.com> Date: Mon, 30 Nov 2015 10:34:07 +0200 > We know vring num is a power of 2, so use & > to mask the high bits. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/vhost/vhost.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 080422f..85f0f0a 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -1366,10 +1366,12 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, > /* Only get avail ring entries after they have been exposed by guest. */ > smp_rmb(); > > + } > + !!! -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 080422f..85f0f0a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1366,10 +1366,12 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, /* Only get avail ring entries after they have been exposed by guest. */ smp_rmb(); + } + /* Grab the next descriptor number they're advertising, and increment * the index we've seen. */ if (unlikely(__get_user(ring_head, - &vq->avail->ring[last_avail_idx % vq->num]))) { + &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) { vq_err(vq, "Failed to read head: idx %d address %p\n", last_avail_idx, &vq->avail->ring[last_avail_idx % vq->num]); @@ -1489,7 +1491,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq, u16 old, new; int start; - start = vq->last_used_idx % vq->num; + start = vq->last_used_idx & (vq->num - 1); used = vq->used->ring + start; if (count == 1) { if (__put_user(heads[0].id, &used->id)) { @@ -1531,7 +1533,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, { int start, n, r; - start = vq->last_used_idx % vq->num; + start = vq->last_used_idx & (vq->num - 1); n = vq->num - start; if (n < count) { r = __vhost_add_used_n(vq, heads, n);
We know vring num is a power of 2, so use & to mask the high bits. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/vhost/vhost.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)