virtio: allow drivers to validate features

Some drivers can't support all features in all configurations.  At the
moment we blindly set FEATURES_OK and later FAILED.  Support this better
by adding a callback drivers can use to do some early checks.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2017-03-29 19:06:20 +03:00
parent 2e123b44a3
commit 404123c2db
2 changed files with 7 additions and 0 deletions

View File

@ -232,6 +232,12 @@ static int virtio_dev_probe(struct device *_d)
if (device_features & (1ULL << i))
__virtio_set_bit(dev, i);
if (drv->validate) {
err = drv->validate(dev);
if (err)
goto err;
}
err = virtio_finalize_features(dev);
if (err)
goto err;

View File

@ -167,6 +167,7 @@ struct virtio_driver {
unsigned int feature_table_size;
const unsigned int *feature_table_legacy;
unsigned int feature_table_size_legacy;
int (*validate)(struct virtio_device *dev);
int (*probe)(struct virtio_device *dev);
void (*scan)(struct virtio_device *dev);
void (*remove)(struct virtio_device *dev);