Re: [PATCH 1/7] PCI/TSM: Add pci_tsm_{bind,unbind}() methods for instantiating TDIs

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

Aneesh Kumar K.V wrote:
> Alexey Kardashevskiy <aik@amd.com> writes:
> 
> > On 27/8/25 13:52, Dan Williams wrote:
> >
> >
> > I suggest changing "pci_tsm_{bind,unbind}()" to "pci_tsm_bind/pci_tsm_unbind" or "pci_tsm_bind/_unbind" as otherwise cannot grep for pci_tsm_bind in git log.
> >
> >
> >> After a PCIe device has established a secure link and session between a TEE
> >> Security Manager (TSM) and its local Device Security Manager (DSM), the
> >> device or its subfunctions are candidates to be bound to a private memory
> >> context, a TVM. A PCIe device function interface assigned to a TVM is a TEE
> >> Device Interface (TDI).
> >> 
> >> The pci_tsm_bind() requests the low-level TSM driver to associate the
> >> device with private MMIO and private IOMMU context resources of a given TVM
> >> represented by a @kvm argument. A device in the bound state corresponds to
> >> the TDISP protocol LOCKED state and awaits validation by the TVM. It is a
> >> 'struct pci_tsm_link_ops' operation because, similar to IDE establishment,
> >> it involves host side resource establishment and context setup on behalf of
> >> the guest. It is also expected to be performed lazily to allow for
> >> operation of the device in non-confidential "shared" context for pre-lock
> >> configuration.
> >> 
> >
> >
> >
> >> Co-developed-by: Xu Yilun <yilun.xu@linux.intel.com>
> >> Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
> >> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> >> ---
> >>   drivers/pci/tsm.c       | 95 +++++++++++++++++++++++++++++++++++++++++
> >>   include/linux/pci-tsm.h | 30 +++++++++++++
> >>   2 files changed, 125 insertions(+)
> >> 
> >> diff --git a/drivers/pci/tsm.c b/drivers/pci/tsm.c
> >> index 092e81c5208c..302a974f3632 100644
> >> --- a/drivers/pci/tsm.c
> >> +++ b/drivers/pci/tsm.c
> >> @@ -251,6 +251,99 @@ static int remove_fn(struct pci_dev *pdev, void *data)
> >>   	return 0;
> >>   }
> >>   
> >> +/*
> >> + * Note, this helper only returns an error code and takes an argument for
> >> + * compatibility with the pci_walk_bus() callback prototype. pci_tsm_unbind()
> >> + * always succeeds.
> >> + */
> >> +static int __pci_tsm_unbind(struct pci_dev *pdev, void *data)
> >> +{
> >> +	struct pci_tdi *tdi;
> >> +	struct pci_tsm_pf0 *tsm_pf0;
> >> +
> >> +	lockdep_assert_held(&pci_tsm_rwsem);
> >> +
> >> +	if (!pdev->tsm)
> >> +		return 0;
> >> +
> >> +	tsm_pf0 = to_pci_tsm_pf0(pdev->tsm);
> >
> > What is expected to be passed to __pci_tsm_unbind/pci_tsm_bind as pdev - PF0 or TEE-IO VF? I guess the latter.
> >
> > But to_pci_tsm_pf0() casts the pdev's tsm to pci_tsm_pf0 which makes sense for PF0 but not for VFs.
> >
> > What do I miss and how does this work for you? Thanks,
> >
> 
> I guess this needs
> 
> modified   drivers/pci/tsm.c
> @@ -44,7 +44,7 @@ static inline bool has_tee(struct pci_dev *pdev)
>  /* 'struct pci_tsm_pf0' wraps 'struct pci_tsm' when ->dsm == ->pdev (self) */
>  static struct pci_tsm_pf0 *to_pci_tsm_pf0(struct pci_tsm *pci_tsm)
>  {
> -	struct pci_dev *pdev = pci_tsm->pdev;
> +	struct pci_dev *pdev = pci_tsm->dsm;

Yup, guess I should have read one more message in the thread before
taking the time go off and finish off v6.