On 2011-10-24 18:05, Michael S. Tsirkin wrote: >> This is what I have in mind: >> - devices set PBA bit if MSI message cannot be sent due to mask (*) >> - core checks&clears PBA bit on unmask, injects message if bit was set >> - devices clear PBA bit if message reason is resolved before unmask (*) > > OK, but practically, when exactly does the device clear PBA?
Consider a network adapter that signals messages in a RX ring: If the corresponding vector is masked while the guest empties the ring, I strongly assume that the device is supposed to take back the pending bit in that case so that there is no interrupt inject on a later vector unmask operation. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
