diff options
Diffstat (limited to 'drivers/net/xen-netback/interface.c')
| -rw-r--r-- | drivers/net/xen-netback/interface.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index f15ba3de6195..0c8a02a1ead7 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -585,6 +585,7 @@ int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref, struct net_device *dev = vif->dev; void *addr; struct xen_netif_ctrl_sring *shared; + RING_IDX rsp_prod, req_prod; int err; err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), @@ -593,7 +594,14 @@ int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref, goto err; shared = (struct xen_netif_ctrl_sring *)addr; - BACK_RING_INIT(&vif->ctrl, shared, XEN_PAGE_SIZE); + rsp_prod = READ_ONCE(shared->rsp_prod); + req_prod = READ_ONCE(shared->req_prod); + + BACK_RING_ATTACH(&vif->ctrl, shared, rsp_prod, XEN_PAGE_SIZE); + + err = -EIO; + if (req_prod - rsp_prod > RING_SIZE(&vif->ctrl)) + goto err_unmap; err = bind_interdomain_evtchn_to_irq(vif->domid, evtchn); if (err < 0) |