diff options
Diffstat (limited to 'drivers/lguest/lguest_device.c')
| -rw-r--r-- | drivers/lguest/lguest_device.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index d0a1d8a45c81..89088d6538fd 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -94,7 +94,7 @@ static unsigned desc_size(const struct lguest_device_desc *desc) } /* This gets the device's feature bits. */ -static u32 lg_get_features(struct virtio_device *vdev) +static u64 lg_get_features(struct virtio_device *vdev) { unsigned int i; u32 features = 0; @@ -126,7 +126,7 @@ static void status_notify(struct virtio_device *vdev) * sorted out, this routine is called so we can tell the Host which features we * understand and accept. */ -static void lg_finalize_features(struct virtio_device *vdev) +static int lg_finalize_features(struct virtio_device *vdev) { unsigned int i, bits; struct lguest_device_desc *desc = to_lgdev(vdev)->desc; @@ -136,20 +136,25 @@ static void lg_finalize_features(struct virtio_device *vdev) /* Give virtio_ring a chance to accept features. */ vring_transport_features(vdev); + /* Make sure we don't have any features > 32 bits! */ + BUG_ON((u32)vdev->features != vdev->features); + /* - * The vdev->feature array is a Linux bitmask: this isn't the same as a - * the simple array of bits used by lguest devices for features. So we - * do this slow, manual conversion which is completely general. + * Since lguest is currently x86-only, we're little-endian. That + * means we could just memcpy. But it's not time critical, and in + * case someone copies this code, we do it the slow, obvious way. */ memset(out_features, 0, desc->feature_len); bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8; for (i = 0; i < bits; i++) { - if (test_bit(i, vdev->features)) + if (__virtio_test_bit(vdev, i)) out_features[i / 8] |= (1 << (i % 8)); } /* Tell Host we've finished with this device's feature negotiation */ status_notify(vdev); + + return 0; } /* Once they've found a field, getting a copy of it is easy. */ |