On Sun, Jul 16, 2023 at 11:15:35AM +0300, Avihai Horon wrote: > Hi all, > > The first patch in this series adds a small optimization to VFIO > migration by moving the STOP_COPY->STOP transition to > vfio_save_cleanup(). Testing with a ConnectX-7 VFIO device showed that > this can reduce downtime by up to 6%. > > The rest of the series adds P2P support for VFIO migration. > > VFIO migration uAPI defines an optional intermediate P2P quiescent > state. While in the P2P quiescent state, P2P DMA transactions cannot be > initiated by the device, but the device can respond to incoming ones. > Additionally, all outstanding P2P transactions are guaranteed to have > been completed by the time the device enters this state.
For clarity it is "all outstanding DMA transactions are guarenteed to have been completed" - the device has no idea if something is P2P or not. > The purpose of this state is to support migration of multiple devices > that are doing P2P transactions between themselves. s/are/might/ Jason
