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>
This commit is contained in:
Michael S. Tsirkin 2014-11-27 13:45:58 +02:00
parent d025477368
commit 93d389f820
7 changed files with 21 additions and 0 deletions

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@ -136,6 +136,9 @@ static void lg_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);
/*
* Since lguest is currently x86-only, we're little-endian. That
* means we could just memcpy. But it's not time critical, and in

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@ -96,6 +96,9 @@ static void mic_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);
memset_io(out_features, 0, feature_len);
bits = min_t(unsigned, feature_len,
sizeof(vdev->features)) * 8;

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@ -227,6 +227,9 @@ static void rproc_virtio_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);
/*
* Remember the finalized features of our vdev, and provide it
* to the remote processor once it is powered on.

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@ -103,6 +103,9 @@ static void kvm_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);
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {

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@ -714,6 +714,9 @@ static void virtio_ccw_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);
features->index = 0;
features->features = cpu_to_le32(vdev->features);
/* Write the feature bits to the host. */

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@ -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);
}

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@ -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);
}