[libvirt] libvirt mdev migration, mdevctl integration

[Cornelia Huck]

On Tue, 10 Dec 2019 10:09:34 +0000
Daniel P. Berrangé <berrange at redhat.com> wrote:

> On Mon, Dec 09, 2019 at 02:23:38PM -0600, Jonathon Jongsma wrote:
> > mdevctl also supports assigning arbitrary sysfs attributes to a device.
> > These attributes have an explicit ordering and are written to sysfs in
> > the specified order when a device is started. This might be the only
> > thing that doesn't fit into the current xml format.  

Not sure how much the 'explicit ordering' is actually required by the
devices currently supporting this. It's probably a good idea to keep
this, though, as future device types might end up having such a
requirement.

> Well we need to define a schema, but there will need to be some kind
> of validation added because. AFAICT, mdevctl does no validation, so a
> plain passthrough of this allows arbitrary writing of files anywhere
> on the host given a suitable malicious attribute name.

Uh, we really should do something about that in mdevctl as well. Writes
outside the sysfs hierarchy should not be allowed.