Re: [RFC PATCH v1 08/11] PCI/TSM: Bind CTLV attestation to connected and locked contexts

[Jason Gunthorpe <jgg@nvidia.com>]

On Fri, Oct 30, 2026 at 03:08:52PM +0100, Jiri Pirko wrote:
> Wed, Oct 28, 2026 at 04:26:15PM +0100, aneesh.kumar@kernel.org wrote:
> 
> [..]
> 
> > 		available authentication methods for the device.
> > 
> > 		When present and the tsm/ attribute directory is present, the
> >-		authenticated attribute is an alias for the device 'connect'
> >-		state. See the 'tsm/connect' attribute for more details.
> >+		authenticated attribute reports the TSM name only after secure
> >+		session and stream setup succeed, otherwise an empty string.
> >+		Connection control uses tsm/connect and tsm/disconnect.
> > 		This is a "link" TSM attribute, see
> > 		Documentation/ABI/testing/sysfs-class-tsm.
> 
> [..]
> 
> > static ssize_t authenticated_show(struct device *dev,
> > 				  struct device_attribute *attr, char *buf)
> > {
> >-	/*
> >-	 * When the SPDM session established via TSM the 'authenticated' state
> >-	 * of the device is identical to the connect state.
> >-	 */
> >-	return connect_show(dev, attr, buf);
> >+	struct pci_dev *pdev = to_pci_dev(dev);
> >+	struct pci_tsm_pf0 *pf0;
> >+	int rc;
> >+
> >+	ACQUIRE(rwsem_read_intr, lock)(&pci_tsm_rwsem);
> >+	rc = ACQUIRE_ERR(rwsem_read_intr, &lock);
> >+	if (rc)
> >+		return rc;
> >+
> >+	if (!pdev->tsm || !pdev->tsm->dsm_dev)
> >+		return sysfs_emit(buf, "\n");
> >+
> >+	pf0 = to_pci_tsm_pf0(pdev->tsm);
> >+	if (!pf0 || !pf0->stream_connected || pf0->base_tsm.error)
> >+		return sysfs_emit(buf, "\n");
> >+
> >+	return sysfs_emit(buf, "%s\n", dev_name(&pdev->tsm->tsm_dev->dev));
> > }
> > static DEVICE_ATTR_RO(authenticated);
> 
> I had in mind removing this attribute alongside the staged connect
> change and reporting authentication state through SPDM_GET.
> 
> This instead retains the attribute and changes when it reports the TSM
> name. Could we settle that together with the SPDM_GET interface rather
> than maintaining parallel authentication-state queries?
> 
> Jason, what do you think?

I'm not keen on any of the sysfs, I'd like to understand who is
expected to use this.

If we imagine a systemd-device-accept-d kind of flow I don't see any
need to duplicate things in attestation subsystem in sysfs..

I'm not sure 'stream connected' is even right, as in my last note we
should not consider the thing authenticated until we actually pass
userspace EVIDENCE_ACCEPT, even if the TSM has established a SPDM
session.

Jason