litmus-rt.git/drivers/s390/kvm, branch test

KVM: s390: virtio-ccw: don't overwrite config space values

2015-07-10T16:49:37+00:00

commit 431dae778aea4eed31bd12e5ee82edc571cd4d70 upstream.

Eric noticed problems with vhost-scsi and virtio-ccw: vhost-scsi
complained about overwriting values in the config space, which
was triggered by a broken implementation of virtio-ccw's config
get/set routines. It was probably sheer luck that we did not hit
this before.

When writing a value to the config space, the WRITE_CONF ccw will
always write from the beginning of the config space up to and
including the value to be set. If the config space up to the value
has not yet been retrieved from the device, however, we'll end up
overwriting values. Keep track of the known config space and update
if needed to avoid this.

Moreover, READ_CONF will only read the number of bytes it has been
instructed to retrieve, so we must not copy more than that to the
buffer, or we might overwrite trailing values.

Reported-by: Eric Farman 
Signed-off-by: Cornelia Huck 
Reviewed-by: Eric Farman 
Tested-by: Eric Farman 
Signed-off-by: Christian Borntraeger 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

virtio_ccw: support non-legacy balloon devices

2015-04-15T03:11:11+00:00

As of last patch, virtio_device_is_legacy_only is always false,
drop the test from virtio ccw.

Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Christian Borntraeger 
Reviewed-by: Cornelia Huck 
Signed-off-by: Rusty Russell  (slight reword)

virtio_ccw: finalize_features error handling

2014-12-09T19:42:06+00:00

We previously tried to use device even if finalize_features failed, but
that's wrong since driver and device are now out of sync.

Fail probe if we detect failures during finalize_features.

Signed-off-by: Cornelia Huck 
Signed-off-by: Michael S. Tsirkin

virtio_ccw: future-proof finalize_features

2014-12-09T19:42:06+00:00

We never negotiate revision > 1, but just to
make this code more likely to work when we do,
require VERSION_1 with any revision >= 1.

Signed-off-by: Michael S. Tsirkin 
Acked-by: Cornelia Huck

virtio_ccw: rev 1 devices set VIRTIO_F_VERSION_1

2014-12-09T19:41:58+00:00

What does it mean if rev 1 device does not set
VIRTIO_F_VERSION_1? E.g. is it native endian?

Let's not even try to drive such devices:
fail attempts to finalize features.
virtio core will detect this and bail out.

Signed-off-by: Michael S. Tsirkin

virtio: allow finalize_features to fail

2014-12-09T14:32:32+00:00

This will make it easy for transports to validate features and return
failure.

Signed-off-by: Michael S. Tsirkin

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

2014-12-09T14:32:32+00:00

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 
Reviewed-by: Cornelia Huck

KVM: s390: enable virtio-ccw revision 1

2014-12-09T10:05:27+00:00

Now that virtio-ccw has everything needed to support virtio 1.0 in
place, try to enable it if the host supports it.

Reviewed-by: David Hildenbrand 
Signed-off-by: Cornelia Huck 
Signed-off-by: Michael S. Tsirkin

KVM: s390 allow virtio_ccw status writes to fail

2014-12-09T10:05:27+00:00

Gracefully handle failure to write device status.
We really should handle other errors as well, but this one is needed for
virtio 1.0 compliance.

Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Cornelia Huck

KVM: s390: virtio-ccw revision 1 SET_VQ

2014-12-09T10:05:26+00:00

The CCW_CMD_SET_VQ command has a different format for revision 1+
devices, allowing to specify a more complex virtqueue layout. For
now, we stay however with the old layout and simply use the new
command format for virtio-1 devices.

Signed-off-by: Cornelia Huck 
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: David Hildenbrand