Messages in this thread | | | Date | Tue, 6 Dec 2022 16:38:11 +0100 | From | Christoph Hellwig <> | Subject | Re: [RFC PATCH 1/5] nvme-pci: add function nvme_submit_vf_cmd to issue admin commands for VF driver. |
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On Tue, Dec 06, 2022 at 11:22:33AM -0400, Jason Gunthorpe wrote: > > controlled functions (which could very well be, and in some designs > > are, additional PFs and not VFs) by controlling function. > > In principle PF vs VF doesn't matter much - the question is really TLP > labeling. If the spec says RID A is the controlling RID and RID B is > the guest RID, then it doesn't matter if they have a PF/VF > relationship or PF/PF relationship.
Yes. Or in fact if you use PASIDs inside a single function.
> We have locking issues in Linux SW connecting different SW drivers for > things that are not a PF/VF relationship, but perhaps that can be > solved.
And I think the only reasonable answer is that the entire workflow must be 100% managed from the controlling function, and the controlled function is just around for a ride, with the controlling function enabling/disabling it as needed without ever interacting with software that directly deals with the controlled function.
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