Eric Lee / smarc-ti-linux-kernel

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Commit ce15408f350c4b97635618692a45aedabfdd2696

Authored by Michael S. Tsirkin
1 parent b6098c3042
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

virtio_ccw: legacy: don't negotiate rev 1/features 

Legacy balloon device doesn't pretend to support revision 1 or 64 bit
features.

But just in case someone implements a broken one that does, let's not
even try to drive legacy only devices using revision 1, and let's not
give them a chance to say they support VIRTIO_F_VERSION_1 by not reading
or writing high feature bits.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>

Showing 1 changed file with 13 additions and 3 deletions Side-by-side Diff

drivers/s390/kvm/virtio_ccw.c
Diff comments   View file @ ce15408
... ... @@ -733,6 +733,9 @@
733 733  
734 734 rc = le32_to_cpu(features->features);
735 735  
  736 + if (vcdev->revision == 0)
  737 + goto out_free;
  738 +
736 739 /* Read second half of the feature bits from the host. */
737 740 features->index = 1;
738 741 ccw->cmd_code = CCW_CMD_READ_FEAT;
... ... @@ -775,6 +778,9 @@
775 778 ccw->cda = (__u32)(unsigned long)features;
776 779 ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
777 780  
  781 + if (vcdev->revision == 0)
  782 + goto out_free;
  783 +
778 784 features->index = 1;
779 785 features->features = cpu_to_le32(vdev->features >> 32);
780 786 /* Write the second half of the feature bits to the host. */
... ... @@ -1182,9 +1188,13 @@
1182 1188 vcdev->vdev.id.vendor = cdev->id.cu_type;
1183 1189 vcdev->vdev.id.device = cdev->id.cu_model;
1184 1190  
1185   - ret = virtio_ccw_set_transport_rev(vcdev);
1186   - if (ret)
1187   - goto out_free;
  1191 + if (virtio_device_is_legacy_only(vcdev->vdev.id)) {
  1192 + vcdev->revision = 0;
  1193 + } else {
  1194 + ret = virtio_ccw_set_transport_rev(vcdev);
  1195 + if (ret)
  1196 + goto out_free;
  1197 + }
1188 1198  
1189 1199 ret = register_virtio_device(&vcdev->vdev);
1190 1200 if (ret) {