From: Mateusz Polrola mateuszx.potrola@intel.com
When exporter or importer is disconnected, ring buffer should be reinitialzed, otherwise on next reconnection exporter/importer will receive old requests/responses remaining in the ring buffer, which are not valid anymore.
This patch also blocks back ring irq until communication channel is initialized and fully active to prevent a race condition.
Signed-off-by: Dongwon Kim dongwon.kim@intel.com --- .../xen/hyper_dmabuf/xen/hyper_dmabuf_xen_comm.c | 24 +++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_comm.c b/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_comm.c index 5e7a250..b629032 100644 --- a/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_comm.c +++ b/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_comm.c @@ -282,6 +282,7 @@ int hyper_dmabuf_xen_init_tx_rbuf(int domid) void hyper_dmabuf_xen_cleanup_tx_rbuf(int domid) { struct xen_comm_tx_ring_info *ring_info; + struct xen_comm_rx_ring_info *rx_ring_info;
/* check if we at all have exporter ring for given rdomain */ ring_info = xen_comm_find_tx_ring(domid); @@ -307,6 +308,12 @@ void hyper_dmabuf_xen_cleanup_tx_rbuf(int domid) (unsigned long) ring_info->ring_front.sring);
kfree(ring_info); + + rx_ring_info = xen_comm_find_rx_ring(domid); + if (!rx_ring_info) + return; + + BACK_RING_INIT(&(rx_ring_info->ring_back), rx_ring_info->ring_back.sring, PAGE_SIZE); }
/* importer needs to know about shared page and port numbers for @@ -378,9 +385,8 @@ int hyper_dmabuf_xen_init_rx_rbuf(int domid)
BACK_RING_INIT(&ring_info->ring_back, sring, PAGE_SIZE);
- ret = bind_interdomain_evtchn_to_irqhandler(domid, rx_port, - back_ring_isr, 0, - NULL, (void*)ring_info); + ret = bind_interdomain_evtchn_to_irq(domid, rx_port); + if (ret < 0) { return -EINVAL; } @@ -399,6 +405,10 @@ int hyper_dmabuf_xen_init_rx_rbuf(int domid) ret = hyper_dmabuf_xen_init_tx_rbuf(domid); }
+ ret = request_irq(ring_info->irq, + back_ring_isr, 0, + NULL, (void*)ring_info); + return ret; }
@@ -406,6 +416,7 @@ int hyper_dmabuf_xen_init_rx_rbuf(int domid) void hyper_dmabuf_xen_cleanup_rx_rbuf(int domid) { struct xen_comm_rx_ring_info *ring_info; + struct xen_comm_tx_ring_info *tx_ring_info; struct page *shared_ring;
/* check if we have importer ring created for given sdomain */ @@ -425,6 +436,13 @@ void hyper_dmabuf_xen_cleanup_rx_rbuf(int domid) gnttab_free_pages(1, &shared_ring);
kfree(ring_info); + + tx_ring_info = xen_comm_find_tx_ring(domid); + if (!tx_ring_info) + return; + + SHARED_RING_INIT(tx_ring_info->ring_front.sring); + FRONT_RING_INIT(&(tx_ring_info->ring_front), tx_ring_info->ring_front.sring, PAGE_SIZE); }
int hyper_dmabuf_xen_init_comm_env(void)