xen-netback: add control ring boilerplate
My recent patch to include/xen/interface/io/netif.h defines a new shared
ring (in addition to the rx and tx rings) for passing control messages
from a VM frontend driver to a backend driver.
This patch adds the necessary code to xen-netback to map this new shared
ring, should it be created by a frontend, but does not add implementations
for any of the defined protocol messages. These are added in a subsequent
patch for clarity.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index f5231a2..78a10d2 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -128,6 +128,15 @@
return IRQ_HANDLED;
}
+irqreturn_t xenvif_ctrl_interrupt(int irq, void *dev_id)
+{
+ struct xenvif *vif = dev_id;
+
+ wake_up(&vif->ctrl_wq);
+
+ return IRQ_HANDLED;
+}
+
int xenvif_queue_stopped(struct xenvif_queue *queue)
{
struct net_device *dev = queue->vif->dev;
@@ -527,9 +536,66 @@
rtnl_unlock();
}
-int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
- unsigned long rx_ring_ref, unsigned int tx_evtchn,
- unsigned int rx_evtchn)
+int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
+ unsigned int evtchn)
+{
+ struct net_device *dev = vif->dev;
+ void *addr;
+ struct xen_netif_ctrl_sring *shared;
+ struct task_struct *task;
+ int err = -ENOMEM;
+
+ err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
+ &ring_ref, 1, &addr);
+ if (err)
+ goto err;
+
+ shared = (struct xen_netif_ctrl_sring *)addr;
+ BACK_RING_INIT(&vif->ctrl, shared, XEN_PAGE_SIZE);
+
+ init_waitqueue_head(&vif->ctrl_wq);
+
+ err = bind_interdomain_evtchn_to_irqhandler(vif->domid, evtchn,
+ xenvif_ctrl_interrupt,
+ 0, dev->name, vif);
+ if (err < 0)
+ goto err_unmap;
+
+ vif->ctrl_irq = err;
+
+ task = kthread_create(xenvif_ctrl_kthread, (void *)vif,
+ "%s-control", dev->name);
+ if (IS_ERR(task)) {
+ pr_warn("Could not allocate kthread for %s\n", dev->name);
+ err = PTR_ERR(task);
+ goto err_deinit;
+ }
+
+ get_task_struct(task);
+ vif->ctrl_task = task;
+
+ wake_up_process(vif->ctrl_task);
+
+ return 0;
+
+err_deinit:
+ unbind_from_irqhandler(vif->ctrl_irq, vif);
+ vif->ctrl_irq = 0;
+
+err_unmap:
+ xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
+ vif->ctrl.sring);
+ vif->ctrl.sring = NULL;
+
+err:
+ return err;
+}
+
+int xenvif_connect_data(struct xenvif_queue *queue,
+ unsigned long tx_ring_ref,
+ unsigned long rx_ring_ref,
+ unsigned int tx_evtchn,
+ unsigned int rx_evtchn)
{
struct task_struct *task;
int err = -ENOMEM;
@@ -538,7 +604,8 @@
BUG_ON(queue->task);
BUG_ON(queue->dealloc_task);
- err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
+ err = xenvif_map_frontend_data_rings(queue, tx_ring_ref,
+ rx_ring_ref);
if (err < 0)
goto err;
@@ -614,7 +681,7 @@
unbind_from_irqhandler(queue->tx_irq, queue);
queue->tx_irq = 0;
err_unmap:
- xenvif_unmap_frontend_rings(queue);
+ xenvif_unmap_frontend_data_rings(queue);
netif_napi_del(&queue->napi);
err:
module_put(THIS_MODULE);
@@ -634,7 +701,7 @@
rtnl_unlock();
}
-void xenvif_disconnect(struct xenvif *vif)
+void xenvif_disconnect_data(struct xenvif *vif)
{
struct xenvif_queue *queue = NULL;
unsigned int num_queues = vif->num_queues;
@@ -668,12 +735,32 @@
queue->tx_irq = 0;
}
- xenvif_unmap_frontend_rings(queue);
+ xenvif_unmap_frontend_data_rings(queue);
}
xenvif_mcast_addr_list_free(vif);
}
+void xenvif_disconnect_ctrl(struct xenvif *vif)
+{
+ if (vif->ctrl_task) {
+ kthread_stop(vif->ctrl_task);
+ put_task_struct(vif->ctrl_task);
+ vif->ctrl_task = NULL;
+ }
+
+ if (vif->ctrl_irq) {
+ unbind_from_irqhandler(vif->ctrl_irq, vif);
+ vif->ctrl_irq = 0;
+ }
+
+ if (vif->ctrl.sring) {
+ xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
+ vif->ctrl.sring);
+ vif->ctrl.sring = NULL;
+ }
+}
+
/* Reverse the relevant parts of xenvif_init_queue().
* Used for queue teardown from xenvif_free(), and on the
* error handling paths in xenbus.c:connect().