History

virtio_ccw: add support for 64 bit features.

Negotiate full 64 bit features. Change u32 to u64, make sure to use 1ULL everywhere. Note: devices guarantee that VERSION_1 is clear unless revision 1 is negotiated. Note: We don't need to re-setup the ccw, but we do it for clarity. Based on patches by Rusty, Thomas Huth and Cornelia.

Michael S. Tsirkin committed 11 years ago

Commit 732c56e1 parent 93d389f1 file · +23 −7Browse files

Unified · Split

drivers/s390/kvm/virtio_ccw.c+23−7
@@ -664,7 +664,8 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev) · 663 unmodified lines
664{664{
665 struct virtio_ccw_device *vcdev = to_vc_device(vdev);665 struct virtio_ccw_device *vcdev = to_vc_device(vdev);
666 struct virtio_feature_desc *features;666 struct virtio_feature_desc *features;
667 int ret, rc;667 int ret;
668 u64 rc;
668 struct ccw1 *ccw;669 struct ccw1 *ccw;
669 670
670 ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);671 ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
@@ -677,7 +678,6 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev) · 6 unmodified lines
677 goto out_free;678 goto out_free;
678 }679 }
679 /* Read the feature bits from the host. */680 /* Read the feature bits from the host. */
680 /* TODO: Features > 32 bits */
681 features->index = 0;681 features->index = 0;
682 ccw->cmd_code = CCW_CMD_READ_FEAT;682 ccw->cmd_code = CCW_CMD_READ_FEAT;
683 ccw->flags = 0;683 ccw->flags = 0;
@@ -691,6 +691,16 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev) · 7 unmodified lines
691 691
692 rc = le32_to_cpu(features->features);692 rc = le32_to_cpu(features->features);
693 693
694 /* Read second half of the feature bits from the host. */
695 features->index = 1;
696 ccw->cmd_code = CCW_CMD_READ_FEAT;
697 ccw->flags = 0;
698 ccw->count = sizeof(*features);
699 ccw->cda = (__u32)(unsigned long)features;
700 ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
701 if (ret == 0)
702 rc |= (u64)le32_to_cpu(features->features) << 32;
703
694out_free:704out_free:
695 kfree(features);705 kfree(features);
696 kfree(ccw);706 kfree(ccw);
@@ -714,12 +724,18 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev) · 17 unmodified lines
714 /* Give virtio_ring a chance to accept features. */724 /* Give virtio_ring a chance to accept features. */
715 vring_transport_features(vdev);725 vring_transport_features(vdev);
716 726
717 /* Make sure we don't have any features > 32 bits! */
718 BUG_ON((u32)vdev->features != vdev->features);
719
720 features->index = 0;727 features->index = 0;
721 features->features = cpu_to_le32(vdev->features);728 features->features = cpu_to_le32((u32)vdev->features);
722 /* Write the feature bits to the host. */729 /* Write the first half of the feature bits to the host. */
730 ccw->cmd_code = CCW_CMD_WRITE_FEAT;
731 ccw->flags = 0;
732 ccw->count = sizeof(*features);
733 ccw->cda = (__u32)(unsigned long)features;
734 ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
735
736 features->index = 1;
737 features->features = cpu_to_le32(vdev->features >> 32);
738 /* Write the second half of the feature bits to the host. */
723 ccw->cmd_code = CCW_CMD_WRITE_FEAT;739 ccw->cmd_code = CCW_CMD_WRITE_FEAT;
724 ccw->flags = 0;740 ccw->flags = 0;
725 ccw->count = sizeof(*features);741 ccw->count = sizeof(*features);