From: Aaron Young <aaron.yo...@oracle.com> Date: Fri, 28 Oct 2016 14:26:19 -0400
> From: Aaron Young <aaron.yo...@oracle.com> > > The following patch fixes an issue with the ldmvsw driver where > the network connection of a guest domain becomes non-functional after > the guest domain has panic'd and rebooted. > > The root cause was determined to be from the following series of > events: > > 1. Guest domain panics - resulting in the guest no longer processing > network packets (from ldmvsw driver) > 2. The ldmvsw driver (in the control domain) eventually exerts flow > control due to no more available tx drings and stops the tx queue > for the guest domain > 3. The LDC of the network connection for the guest is reset when > the guest domain reboots after the panic. > 4. The LDC reset event is received by the ldmvsw driver and the ldmvsw > responds by clearing the tx queue for the guest. > 5. ldmvsw waits indefinitely for a DATA ACK from the guest - which is > the normal method to re-enable the tx queue. But the ACK never comes > because the tx queue was cleared due to the LDC reset. > > To fix this issue, in addition to clearing the tx queue, re-enable the > tx queue on a LDC reset. This prevents the ldmvsw from getting caught in > this deadlocked state of waiting for a DATA ACK which will never come. > > Signed-off-by: Aaron Young <aaron.yo...@oracle.com> > Acked-by: Sowmini Varadhan <sowmini.varad...@oracle.com> Applied, thank you.
