virtio-serial: enable virtio console emergency write feature

Add support for enabling the virtio 1.0 "emergency write"
(VIRTIO_CONSOLE_F_EMERG_WRITE) feature. The previous patch introduced
the plumbing required for this; now we expose the virtio feature to
the guest. The feature is disabled for compatibility machines to avoid
exposing a new feature to existing guests.

As required by the virtio 1.0 spec, the emergency write functionality
is available to the guest even if the guest doesn't negotatiate the
feature, as well as before feature negotation.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Sascha Silbe 2016-09-27 15:43:37 +02:00 committed by Michael S. Tsirkin
parent 09da01c3f2
commit a06b1dae47
3 changed files with 15 additions and 3 deletions

View file

@ -184,6 +184,8 @@ struct VirtIOSerial {
struct VirtIOSerialPostLoad *post_load;
virtio_serial_conf serial;
uint64_t host_features;
};
/* Interface to the virtio-serial bus */