Re: [PATCH v5 04/10] PCI/TSM: Authenticate devices via platform TSM

[<dan.j.williams@intel.com>]

Alexey Kardashevskiy wrote:
[..]
> > +struct pci_tsm_ops {
> > +	/*
> > +	 * struct pci_tsm_link_ops - Manage physical link and the TSM/DSM session
> > +	 * @probe: allocate context (wrap 'struct pci_tsm') for follow-on link
> > +	 *	   operations
> > +	 * @remove: destroy link operations context
> > +	 * @connect: establish / validate a secure connection (e.g. IDE)
> > +	 *	     with the device
> > +	 * @disconnect: teardown the secure link
> > +	 *
> > +	 * Context: @probe, @remove, @connect, and @disconnect run under
> > +	 * pci_tsm_rwsem held for write to sync with TSM unregistration and
> > +	 * mutual exclusion of @connect and @disconnect. @connect and
> > +	 * @disconnect additionally run under the DSM lock (struct
> > +	 * pci_tsm_pf0::lock) as well as @probe and @remove of the subfunctions.
> > +	 */
> > +	struct_group_tagged(pci_tsm_link_ops, link_ops,
> > +		struct pci_tsm *(*probe)(struct pci_dev *pdev);
> 
> 
> struct pci_tsm *(*probe)(struct pci_dev *pdev, struct tsm_dev *tsm)
> 
> as otherwise there is no way to get from pci_dev to tsm_dev (which is sev_device - that thing with request/response buffers for guest requests, etc).

Oh, good point. My sample driver was still stuck in the TSM singleton
universe, indeed this needs to pass the tsm_dev will add, same for
->lock().

> Or add a simple void* to tsm_register() and pci_tsm_ops::probe().

No, let's not give up type-safety unnecessarily.

> Or I can add (which way?) and maintain in my tree. Thanks,

As mentioned in the cover letter for the past few revisions I still have
an open invitation and hope that tsm.git / kernel.org gets to a point
where multiple vendors kernel and VMM trees are unified. So I will spin
an urgent incremental fixup for this, rebase #staging and post a new
devsec-20250828 tag.

I think the shared staging tree will be needed because of the long road
ahead on coming to consensus on all the DMABUF/VFIO/IOMMUFD ABI
concerns. I also want to show 2 vendors merged in that tree before
asking upstream to merge any of this.

If we can get the PCI/TSM core stabilized (2 vendors) and the guest side
encrypted MMIO and DMA details settled (including device-core changes) I
would feel comfortable pushing that upstream while letting the VMM side
ABI discussions continue.