Hmm... this should help:
---
drivers/s390/kvm/kvm_virtio.c | 40 +++++++++++++++++++++++-----------------
1 file changed, 23 insertions(+), 17 deletions(-)
Index: linux-2.6/drivers/s390/kvm/kvm_virtio.c
===================================================================
--- linux-2.6.orig/drivers/s390/kvm/kvm_virtio.c
+++ linux-2.6/drivers/s390/kvm/kvm_virtio.c
@@ -78,27 +78,32 @@ static unsigned desc_size(const struct k
+ desc->config_len;
}
-/*
- * This tests (and acknowleges) a feature bit.
- */
-static bool kvm_feature(struct virtio_device *vdev, unsigned fbit)
+/* This gets the device's feature bits. */
+static u32 kvm_get_features(struct virtio_device *vdev)
{
+ unsigned int i;
+ u32 features = 0;
struct kvm_device_desc *desc = to_kvmdev(vdev)->desc;
- u8 *features;
+ u8 *in_features = kvm_vq_features(desc);
- if (fbit / 8 > desc->feature_len)
- return false;
+ for (i = 0; i < min(desc->feature_len * 8, 32); i++)
+ if (in_features[i / 8] & (1 << (i % 8)))
+ features |= (1 << i);
+ return features;
+}
- features = kvm_vq_features(desc);
- if (!(features[fbit / 8] & (1 << (fbit % 8))))
- return false;
+static void kvm_set_features(struct virtio_device *vdev, u32 features)
+{
+ unsigned int i;
+ struct kvm_device_desc *desc = to_kvmdev(vdev)->desc;
+ /* Second half of bitmap is features we accept. */
+ u8 *out_features = kvm_vq_features(desc) + desc->feature_len;
- /*
- * We set the matching bit in the other half of the bitmap to tell the
- * Host we want to use this feature.
- */
- features[desc->feature_len + fbit / 8] |= (1 << (fbit % 8));
- return true;
+ memset(out_features, 0, desc->feature_len);
+ for (i = 0; i < min(desc->feature_len * 8, 32); i++) {
+ if (features & (1 << i))
+ out_features[i / 8] |= (1 << (i % 8));
+ }
}
/*
@@ -221,7 +226,8 @@ static void kvm_del_vq(struct virtqueue
* The config ops structure as defined...
