Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio bugfixes from Michael Tsirkin:
"Some small, obvious (in hindsight) bugfixes:
- new ioctl in vhost-vdpa has a wrong # - not too late to fix
- vhost has apparently been lacking an smp_rmb() - due to code
duplication :( The duplication will be fixed in the next merge
cycle, this is a minimal fix
- an error message in vhost talks about guest moving used index -
which of course never happens, guest only ever moves the available
index
- i2c-virtio didn't set the driver owner so it did not get refcounted
correctly"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: correct misleading printing information
vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE
virtio: store owner from modules with register_virtio_driver()
vhost: Add smp_rmb() in vhost_enable_notify()
vhost: Add smp_rmb() in vhost_vq_avail_empty()
+42
-17
-1
Documentation/driver-api/virtio/writing_virtio_drivers.rst
-1
Documentation/driver-api/virtio/writing_virtio_drivers.rst
+25
-5
drivers/vhost/vhost.c
+25
-5
drivers/vhost/vhost.c
···
2515
2515
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
2516
2516
2517
2517
if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
2518
-
vq_err(vq, "Guest moved used index from %u to %u",
2518
+
vq_err(vq, "Guest moved avail index from %u to %u",
2519
2519
last_avail_idx, vq->avail_idx);
2520
2520
return -EFAULT;
2521
2521
}
···
2799
2799
r = vhost_get_avail_idx(vq, &avail_idx);
2800
2800
if (unlikely(r))
2801
2801
return false;
2802
-
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
2803
2802
2804
-
return vq->avail_idx == vq->last_avail_idx;
2803
+
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
2804
+
if (vq->avail_idx != vq->last_avail_idx) {
2805
+
/* Since we have updated avail_idx, the following
2806
+
* call to vhost_get_vq_desc() will read available
2807
+
* ring entries. Make sure that read happens after
2808
+
* the avail_idx read.
2809
+
*/
2810
+
smp_rmb();
2811
+
return false;
2812
+
}
2813
+
2814
+
return true;
2805
2815
}
2806
2816
EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
2807
2817
···
2848
2838
&vq->avail->idx, r);
2849
2839
return false;
2850
2840
}
2851
-
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
2852
2841
2853
-
return vq->avail_idx != vq->last_avail_idx;
2842
+
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
2843
+
if (vq->avail_idx != vq->last_avail_idx) {
2844
+
/* Since we have updated avail_idx, the following
2845
+
* call to vhost_get_vq_desc() will read available
2846
+
* ring entries. Make sure that read happens after
2847
+
* the avail_idx read.
2848
+
*/
2849
+
smp_rmb();
2850
+
return true;
2851
+
}
2852
+
2853
+
return false;
2854
2854
}
2855
2855
EXPORT_SYMBOL_GPL(vhost_enable_notify);
2856
2856
+4
-2
drivers/virtio/virtio.c
+4
-2
drivers/virtio/virtio.c
···
362
362
.remove = virtio_dev_remove,
363
363
};
364
364
365
-
int register_virtio_driver(struct virtio_driver *driver)
365
+
int __register_virtio_driver(struct virtio_driver *driver, struct module *owner)
366
366
{
367
367
/* Catch this early. */
368
368
BUG_ON(driver->feature_table_size && !driver->feature_table);
369
369
driver->driver.bus = &virtio_bus;
370
+
driver->driver.owner = owner;
371
+
370
372
return driver_register(&driver->driver);
371
373
}
372
-
EXPORT_SYMBOL_GPL(register_virtio_driver);
374
+
EXPORT_SYMBOL_GPL(__register_virtio_driver);
373
375
374
376
void unregister_virtio_driver(struct virtio_driver *driver)
375
377
{
+5
-2
include/linux/virtio.h
+5
-2
include/linux/virtio.h
···
170
170
171
171
/**
172
172
* struct virtio_driver - operations for a virtio I/O driver
173
-
* @driver: underlying device driver (populate name and owner).
173
+
* @driver: underlying device driver (populate name).
174
174
* @id_table: the ids serviced by this driver.
175
175
* @feature_table: an array of feature numbers supported by this driver.
176
176
* @feature_table_size: number of entries in the feature table array.
···
208
208
return container_of(drv, struct virtio_driver, driver);
209
209
}
210
210
211
-
int register_virtio_driver(struct virtio_driver *drv);
211
+
/* use a macro to avoid include chaining to get THIS_MODULE */
212
+
#define register_virtio_driver(drv) \
213
+
__register_virtio_driver(drv, THIS_MODULE)
214
+
int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
212
215
void unregister_virtio_driver(struct virtio_driver *drv);
213
216
214
217
/* module_virtio_driver() - Helper macro for drivers that don't do
+8
-7
include/uapi/linux/vhost.h
+8
-7
include/uapi/linux/vhost.h
···
179
179
/* Get the config size */
180
180
#define VHOST_VDPA_GET_CONFIG_SIZE _IOR(VHOST_VIRTIO, 0x79, __u32)
181
181
182
-
/* Get the count of all virtqueues */
183
-
#define VHOST_VDPA_GET_VQS_COUNT _IOR(VHOST_VIRTIO, 0x80, __u32)
184
-
185
-
/* Get the number of virtqueue groups. */
186
-
#define VHOST_VDPA_GET_GROUP_NUM _IOR(VHOST_VIRTIO, 0x81, __u32)
187
-
188
182
/* Get the number of address spaces. */
189
183
#define VHOST_VDPA_GET_AS_NUM _IOR(VHOST_VIRTIO, 0x7A, unsigned int)
190
184
···
222
228
#define VHOST_VDPA_GET_VRING_DESC_GROUP _IOWR(VHOST_VIRTIO, 0x7F, \
223
229
struct vhost_vring_state)
224
230
231
+
232
+
/* Get the count of all virtqueues */
233
+
#define VHOST_VDPA_GET_VQS_COUNT _IOR(VHOST_VIRTIO, 0x80, __u32)
234
+
235
+
/* Get the number of virtqueue groups. */
236
+
#define VHOST_VDPA_GET_GROUP_NUM _IOR(VHOST_VIRTIO, 0x81, __u32)
237
+
225
238
/* Get the queue size of a specific virtqueue.
226
239
* userspace set the vring index in vhost_vring_state.index
227
240
* kernel set the queue size in vhost_vring_state.num
228
241
*/
229
-
#define VHOST_VDPA_GET_VRING_SIZE _IOWR(VHOST_VIRTIO, 0x80, \
242
+
#define VHOST_VDPA_GET_VRING_SIZE _IOWR(VHOST_VIRTIO, 0x82, \
230
243
struct vhost_vring_state)
231
244
#endif