Messages in this thread | | | Date | Tue, 19 Apr 2016 11:38:17 -0600 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 0/7] IB/hfi1: Remove write() and use ioctl() for user access |
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On Mon, Apr 18, 2016 at 11:24:11AM -0700, Christoph Hellwig wrote: > On Mon, Apr 18, 2016 at 11:40:47AM -0600, Jason Gunthorpe wrote: > > I wasn't arguing this should integrate into verbs in some way, only > > that the way to access the driver-specific uAPI of a RDMA device should > > be through the RDMA common uAPI and not through a random char dev. > > Well, it's stuff not related to our RDMA userspace API (which _is_ > Verbs, not counting for the complete crackpot abuse in usnic), but > very device specific.
It is weakly related, it uses the same device discovery and security model.
> The stuff the intel driver are doing isn't pretty, but unfortunately > not unusual either - lots of SCSI or network driver have ioctls > like that. Now we could argue if the ioctls should be one the > main node (uverbs) or the a driver private chardev, or not exist > at all and people will have to patch the driver with some vendor > version if they really need it. Examples for either of these > choices exist in the tree.
Right - and the RDMA uAPI has always had an integrated driver-bypass channel as part of the verb uAPI calls, extending that to allow for new-driver-specific calls seems very natural.
Jason
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