From 4e15ee2cb46fed730fe6f0195a86d44e5aeef129 Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Fri, 13 May 2016 09:37:26 +0100 Subject: 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 Acked-by: Wei Liu Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 99 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 94 insertions(+), 5 deletions(-) (limited to 'drivers/net/xen-netback/netback.c') diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 4412a57ec862..ff22b6daa077 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1926,7 +1926,7 @@ static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue) return queue->dealloc_cons != queue->dealloc_prod; } -void xenvif_unmap_frontend_rings(struct xenvif_queue *queue) +void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue) { if (queue->tx.sring) xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif), @@ -1936,9 +1936,9 @@ void xenvif_unmap_frontend_rings(struct xenvif_queue *queue) queue->rx.sring); } -int xenvif_map_frontend_rings(struct xenvif_queue *queue, - grant_ref_t tx_ring_ref, - grant_ref_t rx_ring_ref) +int xenvif_map_frontend_data_rings(struct xenvif_queue *queue, + grant_ref_t tx_ring_ref, + grant_ref_t rx_ring_ref) { void *addr; struct xen_netif_tx_sring *txs; @@ -1965,7 +1965,7 @@ int xenvif_map_frontend_rings(struct xenvif_queue *queue, return 0; err: - xenvif_unmap_frontend_rings(queue); + xenvif_unmap_frontend_data_rings(queue); return err; } @@ -2164,6 +2164,95 @@ int xenvif_dealloc_kthread(void *data) return 0; } +static void make_ctrl_response(struct xenvif *vif, + const struct xen_netif_ctrl_request *req, + u32 status, u32 data) +{ + RING_IDX idx = vif->ctrl.rsp_prod_pvt; + struct xen_netif_ctrl_response rsp = { + .id = req->id, + .type = req->type, + .status = status, + .data = data, + }; + + *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp; + vif->ctrl.rsp_prod_pvt = ++idx; +} + +static void push_ctrl_response(struct xenvif *vif) +{ + int notify; + + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify); + if (notify) + notify_remote_via_irq(vif->ctrl_irq); +} + +static void process_ctrl_request(struct xenvif *vif, + const struct xen_netif_ctrl_request *req) +{ + make_ctrl_response(vif, req, XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED, + 0); + push_ctrl_response(vif); +} + +static void xenvif_ctrl_action(struct xenvif *vif) +{ + for (;;) { + RING_IDX req_prod, req_cons; + + req_prod = vif->ctrl.sring->req_prod; + req_cons = vif->ctrl.req_cons; + + /* Make sure we can see requests before we process them. */ + rmb(); + + if (req_cons == req_prod) + break; + + while (req_cons != req_prod) { + struct xen_netif_ctrl_request req; + + RING_COPY_REQUEST(&vif->ctrl, req_cons, &req); + req_cons++; + + process_ctrl_request(vif, &req); + } + + vif->ctrl.req_cons = req_cons; + vif->ctrl.sring->req_event = req_cons + 1; + } +} + +static bool xenvif_ctrl_work_todo(struct xenvif *vif) +{ + if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl))) + return 1; + + return 0; +} + +int xenvif_ctrl_kthread(void *data) +{ + struct xenvif *vif = data; + + for (;;) { + wait_event_interruptible(vif->ctrl_wq, + xenvif_ctrl_work_todo(vif) || + kthread_should_stop()); + if (kthread_should_stop()) + break; + + while (xenvif_ctrl_work_todo(vif)) + xenvif_ctrl_action(vif); + + cond_resched(); + } + + return 0; +} + static int __init netback_init(void) { int rc = 0; -- cgit v1.2.3-59-g8ed1b