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authorMichael S. Tsirkin <mst@redhat.com>2014-10-07 16:39:42 +0200
committerMichael S. Tsirkin <mst@redhat.com>2014-12-09 12:05:23 +0200
commite16e12be34648777606a2c03a3526409b38f0e63 (patch)
tree36298911ba8eed0a4805c2c30a56d92520d23432 /drivers/lguest
parentd4024af56f7c6cdb7e721994204fb07b2cda8be9 (diff)
downloadkernel-e16e12be34648777606a2c03a3526409b38f0e63.tar.gz
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 <dahi@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'drivers/lguest')
-rw-r--r--drivers/lguest/lguest_device.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index d0a1d8a45c81..97aeb7dce5fc 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -137,14 +137,14 @@ static void lg_finalize_features(struct virtio_device *vdev)
vring_transport_features(vdev);
/*
- * 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));
}