On Fri, Feb 21, 2025 at 05:15:24PM -0800, Dan Williams wrote:
> Xu Yilun wrote:
> > > +static int pci_tsm_disconnect(struct pci_dev *pdev)
> > > +{
> > > + struct pci_tsm *pci_tsm = pdev->tsm;
> > > +
> > > + lockdep_assert_held(&pci_tsm_rwsem);
> > > + if_not_guard(mutex_intr, &pci_tsm->lock)
> > > + return -EINTR;
> > > +
> > > + if (pci_tsm->state < PCI_TSM_CONNECT)
> > > + return 0;
> > > + if (pci_tsm->state < PCI_TSM_INIT)
> > > + return -ENXIO;
> >
> > Check PCI_TSM_INIT first, or this condition will never hit.
> >
> > if (pci_tsm->state < PCI_TSM_INIT)
> > return -ENXIO;
> > if (pci_tsm->state < PCI_TSM_CONNECT)
> > return 0;
> >
> > I suggest the same sequence for pci_tsm_connect().
>
> Good catch, fixed.
>
> [..]
> > > +
> > > +static void __pci_tsm_init(struct pci_dev *pdev)
> > > +{
> > > + bool tee_cap;
> > > +
> > > + if (!is_physical_endpoint(pdev))
> > > + return;
> >
> > This Filters out virtual functions, just because not ready for support,
> > is it?
>
> Do you see a need for PCI core to notify the TSM driver about the
> arrival of VF devices?
I think yes.
>
> My expectation is that a VF TDI communicates with the TSM driver
> relative to its PF.
It is possible, but the PF TSM still need to manage the TDI context for
all it's VFs, like:
struct pci_tdi;
struct pci_tsm {
...
struct pci_dsm *dsm;
struct xarray tdi_xa; // struct pci_tdi array
};
An alternative is we allow VFs has their own pci_tsm, and store their
own tdi contexts in it.
struct pci_tsm {
...
struct pci_dsm *dsm; // point to PF's dsm.
struct pci_tdi *tdi;
};
I perfer the later cause we don't have to seach for TDI context
everytime we have a pdev for VF and do tsm operations on it.
>
> > > +
> > > + tee_cap = pdev->devcap & PCI_EXP_DEVCAP_TEE;
> > > +
> > > + if (!(pdev->ide_cap || tee_cap))
> > > + return;
> > > +
> > > + lockdep_assert_held_write(&pci_tsm_rwsem);
> > > + if (!tsm_ops)
> > > + return;
> > > +
> > > + struct pci_tsm *pci_tsm __free(kfree) = kzalloc(sizeof(*pci_tsm), GFP_KERNEL);
> > > + if (!pci_tsm)
> > > + return;
> > > +
> > > + /*
> > > + * If a physical device has any security capabilities it may be
> > > + * a candidate to connect with the platform TSM
> > > + */
> > > + struct pci_dsm *dsm __free(dsm_remove) = tsm_ops->probe(pdev);
> >
> > IIUC, pdev->tsm should be for every pci function (physical or virtual),
> > pdev->tsm->dsm should be only for physical functions, is it?
>
> Per above I was only expecting physical function, but the bind flow
> might introduce the need for per function (phyiscal or virtual) TDI
> context. I expect that is separate from the PF pdev->tsm context.
Could we embed TDI context in PF's pdev->tsm AND VF's pdev->tsm? From
TDISP spec, TSM covers TDI management so I think it is proper
struct pci_tsm contains TDI context.
Thanks,
Yilun
