virtio: add vhost support for virtio devices

This patch adds a get_vhost() callback function for VirtIODevices that
returns the device's corresponding vhost_dev structure, if the vhost
device is running. This patch also adds a vhost_started flag for
VirtIODevices.

Previously, a VirtIODevice wouldn't be able to tell if its corresponding
vhost device was active or not.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1648819405-25696-3-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/hw/input/vhost-user-input.c b/hw/input/vhost-user-input.c
index aeb0624fe5..1352e372ff 100644
--- a/hw/input/vhost-user-input.c
+++ b/hw/input/vhost-user-input.c
@@ -78,6 +78,12 @@ static void vhost_input_set_config(VirtIODevice *vdev,
     virtio_notify_config(vdev);
 }
 
+static struct vhost_dev *vhost_input_get_vhost(VirtIODevice *vdev)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(vdev);
+    return &vhi->vhost->dev;
+}
+
 static const VMStateDescription vmstate_vhost_input = {
     .name = "vhost-user-input",
     .unmigratable = 1,
@@ -92,6 +98,7 @@ static void vhost_input_class_init(ObjectClass *klass, void *data)
     dc->vmsd = &vmstate_vhost_input;
     vdc->get_config = vhost_input_get_config;
     vdc->set_config = vhost_input_set_config;
+    vdc->get_vhost = vhost_input_get_vhost;
     vic->realize = vhost_input_realize;
     vic->change_active = vhost_input_change_active;
 }