this patch uses the new hvc callback hvc_resize to set the window size
which allows to change the tty size of hvc_console via a hvc_resize
function.

I have added a new feature bit VIRTIO_CONSOLE_F_SIZE. The driver will
change the window size on tty open and via the config_changed callback
of the transport. Currently lguest and kvm_s390 have not implemented this
callback, but the callback can be implemented at a later point in time.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We want others to implement and use virtio, so it makes sense to BSD
license the non-__KERNEL__ parts of the headers to make this crystal
clear.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NMark McLoughlin <markmc@redhat.com>
Acked-by: NRyan Harper <ryanh@us.ibm.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Acked-by: NAnthony Liguori <aliguori@us.ibm.com>

This is an hvc-based virtio console driver.  It's suboptimal becuase
hvc expects to have raw access to interrupts and virtio doesn't assume
that, so it currently polls.

There are two solutions: expose hvc's "kick" interface, or wean off hvc.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>