Re: [PATCH 05/11] PCI/TSM: Authenticate devices via platform TSM

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

Bjorn Helgaas wrote:
> On Thu, Dec 05, 2024 at 02:23:45PM -0800, Dan Williams wrote:
> > The PCIe 6.1 specification, section 11, introduces the Trusted Execution
> > Environment (TEE) Device Interface Security Protocol (TDISP).  This
> > interface definition builds upon Component Measurement and
> > Authentication (CMA), and link Integrity and Data Encryption (IDE). It
> > adds support for assigning devices (PCI physical or virtual function) to
> > a confidential VM such that the assigned device is enabled to access
> > guest private memory protected by technologies like Intel TDX, AMD
> > SEV-SNP, RISCV COVE, or ARM CCA.
> 
> > +++ b/Documentation/ABI/testing/sysfs-bus-pci
> > @@ -583,3 +583,45 @@ Description:
> >  		enclosure-specific indications "specific0" to "specific7",
> >  		hence the corresponding led class devices are unavailable if
> >  		the DSM interface is used.
> > +
> > +What:		/sys/bus/pci/devices/.../tsm/
> > +Date:		July 2024
> > +Contact:	linux-coco@lists.linux.dev
> > +Description:
> > +		This directory only appears if a physical device function supports
> > +		authentication (PCIe CMA-SPDM), interface security (PCIe TDISP), and is
> > +		accepted for secure operation by the platform TSM driver. This attribute
> > +		directory appears dynamically after the platform TSM driver loads. So,
> > +		only after the /sys/class/tsm/tsm0 device arrives can tools assume that
> > +		devices without a tsm/ attribute directory will never have one, before
> > +		that, the security capabilities of the device relative to the platform
> > +		TSM are unknown. See Documentation/ABI/testing/sysfs-class-tsm.
> 
> Wrap to fit in 80 columns like the rest of the file.

Good catch, done.