virtio: use u32, not bitmap for features

It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits.  Just change it to a u32 for now.

Based on patch by Rusty.

Suggested-by: David Hildenbrand <[email protected]>
Signed-off-by: Rusty Russell <[email protected]>
Signed-off-by: Cornelia Huck <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
This commit is contained in:
Michael S. Tsirkin 2014-10-07 16:39:42 +02:00
commit e16e12be34
16 changed files with 42 additions and 74 deletions

View file

@ -106,7 +106,7 @@ static void kvm_finalize_features(struct virtio_device *vdev)
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));
}
}

View file

@ -701,7 +701,6 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev)
{
struct virtio_ccw_device *vcdev = to_vc_device(vdev);
struct virtio_feature_desc *features;
int i;
struct ccw1 *ccw;
ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
@ -715,19 +714,15 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev)
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
i++) {
int highbits = i % 2 ? 32 : 0;
features->index = i;
features->features = cpu_to_le32(vdev->features[i / 2]
>> highbits);
/* Write the feature bits to the host. */
ccw->cmd_code = CCW_CMD_WRITE_FEAT;
ccw->flags = 0;
ccw->count = sizeof(*features);
ccw->cda = (__u32)(unsigned long)features;
ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
}
features->index = 0;
features->features = cpu_to_le32(vdev->features);
/* Write the feature bits to the host. */
ccw->cmd_code = CCW_CMD_WRITE_FEAT;
ccw->flags = 0;
ccw->count = sizeof(*features);
ccw->cda = (__u32)(unsigned long)features;
ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
out_free:
kfree(features);
kfree(ccw);