Messages in this thread | | | Date | Wed, 15 Jan 2014 10:37:07 +0000 | From | Wei Liu <> | Subject | Re: [PATCH net-next] xen-netback: Rework rx_work_todo |
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On Tue, Jan 14, 2014 at 07:28:39PM +0000, Zoltan Kiss wrote: > The recent patch to fix receive side flow control (11b57f) solved the spinning > thread problem, however caused an another one. The receive side can stall, if: > - xenvif_rx_action sets rx_queue_stopped to false > - interrupt happens, and sets rx_event to true > - then xenvif_kthread sets rx_event to false >
If you mean "rx_work_todo" returns false.
In this case
(!skb_queue_empty(&vif->rx_queue) && !vif->rx_queue_stopped) || vif->rx_event;
can still be true, can't it?
> Also, through rx_event a malicious guest can force the RX thread to spin. This > patch ditch that two variable, and rework rx_work_todo. If the thread finds it
This seems to be a bigger problem. Can you elaborate?
Wei.
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