On Thu, Mar 23, 2017 at 03:52:14PM +0000, Jean-Philippe Brucker wrote: > On 23/03/17 14:30, Joerg Roedel wrote: > > Are you sure about the meaning of the stop-marker? Can you point me to > > where it is specified? > > The concept is introduced in the PCI ECN that adds PASIDs to the ATS > specification. I have the following link, which is probably behind a > wall: > > https://pcisig.com/sites/default/files/specification_documents/ECN-PASID-ATS-2011-03-31.pdf > > A Stop Marker is a PPR with flags Read=Write=0, Last=1, targeting the > PASID that is being decommissioned. In section 4.1.2, the specifications > details the two device-specific ways of stopping use of a PASID, with or > without a Stop Marker. When done with a Stop Marker, the function doesn't > have to wait for any outstanding PPR to return, the Stop Marker serves as > a PASID barrier. Thanks for that, I have a closer look. Is that stopper packet visible to software (e.g. is an entry created in the queue)? I have to check whether the AMD IOMMU makes this visible. Joerg
