On 2015年10月29日 14:58, Alexander Duyck wrote: > > Your code was having to do a bunch of shuffling in order to get things > set up so that you could bring the interface back up. I would argue > that it may actually be faster at least on the bring-up to just drop the > old rings and start over since it greatly reduced the complexity and the > amount of device related data that has to be moved. If give up the old ring after migration and keep DMA running before stopping VCPU, it seems we don't need to track Tx/Rx descriptor ring and just make sure that all Rx buffers delivered to stack has been migrated. 1) Dummy write Rx buffer before checking Rx descriptor to ensure packet migrated first. 2) Make a copy of Rx descriptor and then use the copied data to check buffer status. Not use the original descriptor because it won't be migrated and migration may happen between two access of the Rx descriptor. -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
