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>
This commit is contained in:
Paul Durrant
David S. Miller
parent
1ca4673432
commit
4e15ee2cb4
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@ -260,6 +260,11 @@ struct xenvif {
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struct dentry *xenvif_dbg_root;
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#endif
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struct xen_netif_ctrl_back_ring ctrl;
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struct task_struct *ctrl_task;
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wait_queue_head_t ctrl_wq;
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unsigned int ctrl_irq;
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/* Miscellaneous private stuff. */
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struct net_device *dev;
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};
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@ -285,10 +290,15 @@ struct xenvif *xenvif_alloc(struct device *parent,
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int xenvif_init_queue(struct xenvif_queue *queue);
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void xenvif_deinit_queue(struct xenvif_queue *queue);
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int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
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unsigned long rx_ring_ref, unsigned int tx_evtchn,
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unsigned int rx_evtchn);
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void xenvif_disconnect(struct xenvif *vif);
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int xenvif_connect_data(struct xenvif_queue *queue,
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unsigned long tx_ring_ref,
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unsigned long rx_ring_ref,
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unsigned int tx_evtchn,
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unsigned int rx_evtchn);
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void xenvif_disconnect_data(struct xenvif *vif);
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int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
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unsigned int evtchn);
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void xenvif_disconnect_ctrl(struct xenvif *vif);
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void xenvif_free(struct xenvif *vif);
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int xenvif_xenbus_init(void);
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@ -300,10 +310,10 @@ int xenvif_queue_stopped(struct xenvif_queue *queue);
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void xenvif_wake_queue(struct xenvif_queue *queue);
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/* (Un)Map communication rings. */
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void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
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int xenvif_map_frontend_rings(struct xenvif_queue *queue,
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grant_ref_t tx_ring_ref,
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grant_ref_t rx_ring_ref);
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void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue);
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int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
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grant_ref_t tx_ring_ref,
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grant_ref_t rx_ring_ref);
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/* Check for SKBs from frontend and schedule backend processing */
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void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
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@ -318,6 +328,8 @@ void xenvif_kick_thread(struct xenvif_queue *queue);
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int xenvif_dealloc_kthread(void *data);
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int xenvif_ctrl_kthread(void *data);
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void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
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void xenvif_carrier_on(struct xenvif *vif);
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@ -128,6 +128,15 @@ irqreturn_t xenvif_interrupt(int irq, void *dev_id)
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return IRQ_HANDLED;
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}
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irqreturn_t xenvif_ctrl_interrupt(int irq, void *dev_id)
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{
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struct xenvif *vif = dev_id;
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wake_up(&vif->ctrl_wq);
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return IRQ_HANDLED;
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}
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int xenvif_queue_stopped(struct xenvif_queue *queue)
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{
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struct net_device *dev = queue->vif->dev;
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@ -527,9 +536,66 @@ void xenvif_carrier_on(struct xenvif *vif)
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rtnl_unlock();
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}
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int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
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unsigned long rx_ring_ref, unsigned int tx_evtchn,
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unsigned int rx_evtchn)
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int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
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unsigned int evtchn)
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{
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struct net_device *dev = vif->dev;
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void *addr;
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struct xen_netif_ctrl_sring *shared;
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struct task_struct *task;
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int err = -ENOMEM;
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err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
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&ring_ref, 1, &addr);
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if (err)
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goto err;
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shared = (struct xen_netif_ctrl_sring *)addr;
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BACK_RING_INIT(&vif->ctrl, shared, XEN_PAGE_SIZE);
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init_waitqueue_head(&vif->ctrl_wq);
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err = bind_interdomain_evtchn_to_irqhandler(vif->domid, evtchn,
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xenvif_ctrl_interrupt,
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0, dev->name, vif);
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if (err < 0)
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goto err_unmap;
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vif->ctrl_irq = err;
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task = kthread_create(xenvif_ctrl_kthread, (void *)vif,
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"%s-control", dev->name);
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if (IS_ERR(task)) {
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pr_warn("Could not allocate kthread for %s\n", dev->name);
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err = PTR_ERR(task);
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goto err_deinit;
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}
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get_task_struct(task);
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vif->ctrl_task = task;
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wake_up_process(vif->ctrl_task);
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return 0;
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err_deinit:
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unbind_from_irqhandler(vif->ctrl_irq, vif);
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vif->ctrl_irq = 0;
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err_unmap:
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xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
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vif->ctrl.sring);
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vif->ctrl.sring = NULL;
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err:
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return err;
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}
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int xenvif_connect_data(struct xenvif_queue *queue,
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unsigned long tx_ring_ref,
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unsigned long rx_ring_ref,
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unsigned int tx_evtchn,
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unsigned int rx_evtchn)
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{
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struct task_struct *task;
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int err = -ENOMEM;
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@ -538,7 +604,8 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
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BUG_ON(queue->task);
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BUG_ON(queue->dealloc_task);
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err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
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err = xenvif_map_frontend_data_rings(queue, tx_ring_ref,
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rx_ring_ref);
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if (err < 0)
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goto err;
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@ -614,7 +681,7 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
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unbind_from_irqhandler(queue->tx_irq, queue);
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queue->tx_irq = 0;
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err_unmap:
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xenvif_unmap_frontend_rings(queue);
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xenvif_unmap_frontend_data_rings(queue);
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netif_napi_del(&queue->napi);
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err:
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module_put(THIS_MODULE);
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@ -634,7 +701,7 @@ void xenvif_carrier_off(struct xenvif *vif)
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rtnl_unlock();
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}
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void xenvif_disconnect(struct xenvif *vif)
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void xenvif_disconnect_data(struct xenvif *vif)
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{
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struct xenvif_queue *queue = NULL;
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unsigned int num_queues = vif->num_queues;
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@ -668,12 +735,32 @@ void xenvif_disconnect(struct xenvif *vif)
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queue->tx_irq = 0;
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}
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xenvif_unmap_frontend_rings(queue);
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xenvif_unmap_frontend_data_rings(queue);
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}
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xenvif_mcast_addr_list_free(vif);
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}
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void xenvif_disconnect_ctrl(struct xenvif *vif)
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{
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if (vif->ctrl_task) {
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kthread_stop(vif->ctrl_task);
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put_task_struct(vif->ctrl_task);
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vif->ctrl_task = NULL;
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}
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if (vif->ctrl_irq) {
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unbind_from_irqhandler(vif->ctrl_irq, vif);
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vif->ctrl_irq = 0;
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}
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if (vif->ctrl.sring) {
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xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
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vif->ctrl.sring);
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vif->ctrl.sring = NULL;
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}
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}
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/* Reverse the relevant parts of xenvif_init_queue().
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* Used for queue teardown from xenvif_free(), and on the
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* error handling paths in xenbus.c:connect().
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@ -1926,7 +1926,7 @@ static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
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return queue->dealloc_cons != queue->dealloc_prod;
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}
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void xenvif_unmap_frontend_rings(struct xenvif_queue *queue)
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void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
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{
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if (queue->tx.sring)
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xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
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@ -1936,9 +1936,9 @@ void xenvif_unmap_frontend_rings(struct xenvif_queue *queue)
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queue->rx.sring);
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}
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int xenvif_map_frontend_rings(struct xenvif_queue *queue,
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grant_ref_t tx_ring_ref,
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grant_ref_t rx_ring_ref)
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int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
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grant_ref_t tx_ring_ref,
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grant_ref_t rx_ring_ref)
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{
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void *addr;
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struct xen_netif_tx_sring *txs;
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@ -1965,7 +1965,7 @@ int xenvif_map_frontend_rings(struct xenvif_queue *queue,
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return 0;
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err:
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xenvif_unmap_frontend_rings(queue);
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xenvif_unmap_frontend_data_rings(queue);
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return err;
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}
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@ -2164,6 +2164,95 @@ int xenvif_dealloc_kthread(void *data)
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return 0;
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}
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static void make_ctrl_response(struct xenvif *vif,
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const struct xen_netif_ctrl_request *req,
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u32 status, u32 data)
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{
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RING_IDX idx = vif->ctrl.rsp_prod_pvt;
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struct xen_netif_ctrl_response rsp = {
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.id = req->id,
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.type = req->type,
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.status = status,
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.data = data,
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};
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*RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
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vif->ctrl.rsp_prod_pvt = ++idx;
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}
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static void push_ctrl_response(struct xenvif *vif)
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{
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int notify;
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RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
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if (notify)
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notify_remote_via_irq(vif->ctrl_irq);
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}
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static void process_ctrl_request(struct xenvif *vif,
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const struct xen_netif_ctrl_request *req)
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{
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make_ctrl_response(vif, req, XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED,
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0);
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push_ctrl_response(vif);
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}
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static void xenvif_ctrl_action(struct xenvif *vif)
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{
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for (;;) {
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RING_IDX req_prod, req_cons;
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req_prod = vif->ctrl.sring->req_prod;
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req_cons = vif->ctrl.req_cons;
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/* Make sure we can see requests before we process them. */
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rmb();
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if (req_cons == req_prod)
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break;
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while (req_cons != req_prod) {
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struct xen_netif_ctrl_request req;
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RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
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req_cons++;
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process_ctrl_request(vif, &req);
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}
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vif->ctrl.req_cons = req_cons;
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vif->ctrl.sring->req_event = req_cons + 1;
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}
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}
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static bool xenvif_ctrl_work_todo(struct xenvif *vif)
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{
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if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
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return 1;
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return 0;
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}
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int xenvif_ctrl_kthread(void *data)
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{
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struct xenvif *vif = data;
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for (;;) {
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wait_event_interruptible(vif->ctrl_wq,
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xenvif_ctrl_work_todo(vif) ||
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kthread_should_stop());
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if (kthread_should_stop())
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break;
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while (xenvif_ctrl_work_todo(vif))
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xenvif_ctrl_action(vif);
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cond_resched();
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}
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return 0;
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}
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static int __init netback_init(void)
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{
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int rc = 0;
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@ -38,7 +38,8 @@ struct backend_info {
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const char *hotplug_script;
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};
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static int connect_rings(struct backend_info *be, struct xenvif_queue *queue);
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static int connect_data_rings(struct backend_info *be,
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struct xenvif_queue *queue);
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static void connect(struct backend_info *be);
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static int read_xenbus_vif_flags(struct backend_info *be);
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static int backend_create_xenvif(struct backend_info *be);
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@ -367,6 +368,12 @@ static int netback_probe(struct xenbus_device *dev,
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if (err)
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pr_debug("Error writing multi-queue-max-queues\n");
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err = xenbus_printf(XBT_NIL, dev->nodename,
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"feature-ctrl-ring",
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"%u", true);
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if (err)
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pr_debug("Error writing feature-ctrl-ring\n");
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script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
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if (IS_ERR(script)) {
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err = PTR_ERR(script);
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@ -457,7 +464,8 @@ static void backend_disconnect(struct backend_info *be)
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#ifdef CONFIG_DEBUG_FS
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xenvif_debugfs_delif(be->vif);
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#endif /* CONFIG_DEBUG_FS */
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xenvif_disconnect(be->vif);
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xenvif_disconnect_data(be->vif);
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xenvif_disconnect_ctrl(be->vif);
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}
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}
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@ -825,6 +833,48 @@ static void hotplug_status_changed(struct xenbus_watch *watch,
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kfree(str);
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}
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static int connect_ctrl_ring(struct backend_info *be)
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{
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struct xenbus_device *dev = be->dev;
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struct xenvif *vif = be->vif;
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unsigned int val;
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grant_ref_t ring_ref;
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unsigned int evtchn;
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int err;
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err = xenbus_gather(XBT_NIL, dev->otherend,
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"ctrl-ring-ref", "%u", &val, NULL);
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if (err)
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goto done; /* The frontend does not have a control ring */
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ring_ref = val;
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err = xenbus_gather(XBT_NIL, dev->otherend,
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"event-channel-ctrl", "%u", &val, NULL);
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if (err) {
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xenbus_dev_fatal(dev, err,
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"reading %s/event-channel-ctrl",
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dev->otherend);
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goto fail;
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}
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evtchn = val;
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err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
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if (err) {
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xenbus_dev_fatal(dev, err,
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"mapping shared-frame %u port %u",
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ring_ref, evtchn);
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goto fail;
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}
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done:
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return 0;
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fail:
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return err;
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}
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static void connect(struct backend_info *be)
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{
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int err;
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@ -861,6 +911,12 @@ static void connect(struct backend_info *be)
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xen_register_watchers(dev, be->vif);
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read_xenbus_vif_flags(be);
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err = connect_ctrl_ring(be);
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if (err) {
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xenbus_dev_fatal(dev, err, "connecting control ring");
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return;
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}
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/* Use the number of queues requested by the frontend */
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be->vif->queues = vzalloc(requested_num_queues *
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sizeof(struct xenvif_queue));
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@ -896,11 +952,12 @@ static void connect(struct backend_info *be)
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queue->remaining_credit = credit_bytes;
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queue->credit_usec = credit_usec;
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err = connect_rings(be, queue);
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err = connect_data_rings(be, queue);
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if (err) {
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/* connect_rings() cleans up after itself on failure,
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* but we need to clean up after xenvif_init_queue() here,
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* and also clean up any previously initialised queues.
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/* connect_data_rings() cleans up after itself on
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* failure, but we need to clean up after
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* xenvif_init_queue() here, and also clean up any
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* previously initialised queues.
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*/
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xenvif_deinit_queue(queue);
|
||||
be->vif->num_queues = queue_index;
|
||||
|
|
@ -935,15 +992,17 @@ static void connect(struct backend_info *be)
|
|||
|
||||
err:
|
||||
if (be->vif->num_queues > 0)
|
||||
xenvif_disconnect(be->vif); /* Clean up existing queues */
|
||||
xenvif_disconnect_data(be->vif); /* Clean up existing queues */
|
||||
vfree(be->vif->queues);
|
||||
be->vif->queues = NULL;
|
||||
be->vif->num_queues = 0;
|
||||
xenvif_disconnect_ctrl(be->vif);
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
static int connect_rings(struct backend_info *be, struct xenvif_queue *queue)
|
||||
static int connect_data_rings(struct backend_info *be,
|
||||
struct xenvif_queue *queue)
|
||||
{
|
||||
struct xenbus_device *dev = be->dev;
|
||||
unsigned int num_queues = queue->vif->num_queues;
|
||||
|
|
@ -1007,8 +1066,8 @@ static int connect_rings(struct backend_info *be, struct xenvif_queue *queue)
|
|||
}
|
||||
|
||||
/* Map the shared frame, irq etc. */
|
||||
err = xenvif_connect(queue, tx_ring_ref, rx_ring_ref,
|
||||
tx_evtchn, rx_evtchn);
|
||||
err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
|
||||
tx_evtchn, rx_evtchn);
|
||||
if (err) {
|
||||
xenbus_dev_fatal(dev, err,
|
||||
"mapping shared-frames %lu/%lu port tx %u rx %u",
|
||||
|
|
|
|||
Loading…
Reference in New Issue