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authorSascha Silbe <silbe@linux.vnet.ibm.com>2016-09-27 15:43:36 +0200
committerMichael S. Tsirkin <mst@redhat.com>2016-10-10 01:16:57 +0300
commit09da01c3f205b008ce0c7a960092bcc03b383b50 (patch)
tree3a14b14ecfd3209e884e351e40658c183e17801e /hw/char
parent17871f71fd2ff5d76196051470e9604bfb6f0c09 (diff)
virtio-serial: add plumbing for virtio console emergency write support
Add the infrastructure required for the virtio 1.0 "emergency write" (VIRTIO_CONSOLE_F_EMERG_WRITE) feature. Because we don't touch the size of the configuration area, guests will not be able to actually make use of this without further patches. 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>
Diffstat (limited to 'hw/char')
-rw-r--r--hw/char/virtio-serial-bus.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index db57a38546..57419b2b6a 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -75,6 +75,19 @@ static VirtIOSerialPort *find_port_by_name(char *name)
return NULL;
}
+static VirtIOSerialPort *find_first_connected_console(VirtIOSerial *vser)
+{
+ VirtIOSerialPort *port;
+
+ QTAILQ_FOREACH(port, &vser->ports, next) {
+ VirtIOSerialPortClass const *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
+ if (vsc->is_console && port->host_connected) {
+ return port;
+ }
+ }
+ return NULL;
+}
+
static bool use_multiport(VirtIOSerial *vser)
{
VirtIODevice *vdev = VIRTIO_DEVICE(vser);
@@ -547,6 +560,29 @@ static void get_config(VirtIODevice *vdev, uint8_t *config_data)
vser->serial.max_virtserial_ports);
}
+/* Guest sent new config info */
+static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
+{
+ VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
+ struct virtio_console_config *config =
+ (struct virtio_console_config *)config_data;
+ uint8_t emerg_wr_lo = le32_to_cpu(config->emerg_wr);
+ VirtIOSerialPort *port = find_first_connected_console(vser);
+ VirtIOSerialPortClass *vsc;
+
+ if (!config->emerg_wr) {
+ return;
+ }
+ /* Make sure we don't misdetect an emergency write when the guest
+ * does a short config write after an emergency write. */
+ config->emerg_wr = 0;
+ if (!port) {
+ return;
+ }
+ vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
+ (void)vsc->have_data(port, &emerg_wr_lo, 1);
+}
+
static void guest_reset(VirtIOSerial *vser)
{
VirtIOSerialPort *port;
@@ -1098,6 +1134,7 @@ static void virtio_serial_class_init(ObjectClass *klass, void *data)
vdc->unrealize = virtio_serial_device_unrealize;
vdc->get_features = get_features;
vdc->get_config = get_config;
+ vdc->set_config = set_config;
vdc->set_status = set_status;
vdc->reset = vser_reset;
vdc->save = virtio_serial_save_device;