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authorMichael S. Tsirkin <mst@redhat.com>2014-11-27 13:45:58 +0200
committerMichael S. Tsirkin <mst@redhat.com>2014-12-09 12:05:24 +0200
commit93d389f82078cf7197152fb10d21977da0883420 (patch)
treec168e5be2acd4e257212006a710af14df2185d80 /drivers/virtio
parentd025477368792b272802146a86e41f81a54d8a19 (diff)
virtio: assert 32 bit features in transports
At this point, no transports set any of the high 32 feature bits. Since transports generally can't (yet) cope with such bits, add BUG_ON checks to make sure they are not set by mistake. Based on rproc patch by Rusty. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_mmio.c3
-rw-r--r--drivers/virtio/virtio_pci.c3
2 files changed, 6 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index c63d0efa947b..aec1daee9ada 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -159,6 +159,9 @@ static void vm_finalize_features(struct virtio_device *vdev)
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
+ /* Make sure we don't have any features > 32 bits! */
+ BUG_ON((u32)vdev->features != vdev->features);
+
writel(0, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
writel(vdev->features, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
}
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 7e0efa7fc384..dd6df979862b 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -119,6 +119,9 @@ static void vp_finalize_features(struct virtio_device *vdev)
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
+ /* Make sure we don't have any features > 32 bits! */
+ BUG_ON((u32)vdev->features != vdev->features);
+
/* We only support 32 feature bits. */
iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
}