On Mon, 1 Feb 2021, Ben Widawsky wrote: > > I haven't seen the update to 8.2.8.4.5 to know yet :) > > > > You make a good point of at least being able to interact with the driver. > > I think you could argue that if the driver binds, then the payload size is > > accepted, in which case it would be strange to get an EINVAL when using > > the ioctl with anything >1MB. > > > > Concern was that if we mask off the reserved bits from the command > > register that we could be masking part of the payload size that is being > > passed if the accepted max is >1MB. Idea was to avoid any possibility of > > this inconsistency. If this is being checked for ioctl, seems like it's > > checking reserved bits. > > > > But maybe I should just wait for the spec update. > > Well, I wouldn't hold your breath (it would be an errata in this case anyway). > My preference would be to just allow allow mailbox payload size to be 2^31 and > not deal with this. > > My question was how strongly do you feel it's an error that should prevent > binding. > I don't have an objection to binding, but doesn't this require that the check in cxl_validate_cmd_from_user() guarantees send_cmd->size_in cannot be greater than 1MB?