Jonathan Cameron wrote:
> On Thu, 15 May 2025 22:47:25 -0700
> Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
>
> > Establish just enough emulated PCI infrastructure to register a sample
> > TSM (platform security manager) driver and have it discover an IDE + TEE
> > (link encryption + device-interface security protocol (TDISP)) capable
> > device.
> >
> > Use the existing a CONFIG_PCI_BRIDGE_EMUL to emulate an IDE capable root
> > port, and open code the emulation of an endpoint device via simulated
> > configuration cycle responses.
> >
> > The devsec_tsm driver responds to the PCI core TSM operations as if it
> > successfully exercised the given interface security protocol message.
> >
> > The devsec_bus and devsec_tsm drivers can be loaded in either order to
> > reflect cases like SEV-TIO where the TSM is PCI-device firmware, and
> > cases like TDX Connect where the TSM is a software agent running on the
> > host CPU.
> >
> > Follow-on patches add common code for TSM managed IDE establishment. For
> > now, just successfully complete setup and teardown of the DSM (device
> > security manager) context as a building block for management of TDI
> > (trusted device interface) instances.
> >
> > # modprobe devsec_bus
> > devsec_bus devsec_bus: PCI host bridge to bus 10000:00
> > pci_bus 10000:00: root bus resource [bus 00-01]
> > pci_bus 10000:00: root bus resource [mem 0xf000000000-0xffffffffff 64bit]
> > pci 10000:00:00.0: [8086:7075] type 01 class 0x060400 PCIe Root Port
> > pci 10000:00:00.0: PCI bridge to [bus 00]
> > pci 10000:00:00.0: bridge window [io 0x0000-0x0fff]
> > pci 10000:00:00.0: bridge window [mem 0x00000000-0x000fffff]
> > pci 10000:00:00.0: bridge window [mem 0x00000000-0x000fffff 64bit pref]
> > pci 10000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
> > pci 10000:01:00.0: [8086:ffff] type 00 class 0x000000 PCIe Endpoint
> > pci 10000:01:00.0: BAR 0 [mem 0xf000000000-0xf0001fffff 64bit pref]
> > pci_doe_abort: pci 10000:01:00.0: DOE: [100] Issuing Abort
> > pci_doe_cache_protocols: pci 10000:01:00.0: DOE: [100] Found protocol 0 vid: 1 prot: 1
> > pci 10000:01:00.0: disabling ASPM on pre-1.1 PCIe device. You can enable it with 'pcie_aspm=force'
> > pci 10000:00:00.0: PCI bridge to [bus 01]
> > pci_bus 10000:01: busn_res: [bus 01] end is updated to 01
> > # modprobe devsec_tsm
> > devsec_tsm_pci_probe: pci 10000:01:00.0: devsec: tsm enabled
> > __pci_tsm_init: pci 10000:01:00.0: TSM: Device security capabilities detected ( ide tee ), TSM attach
> >
> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > Cc: Lukas Wunner <lukas@xxxxxxxxx>
> > Cc: Samuel Ortiz <sameo@xxxxxxxxxxxx>
> > Cc: Alexey Kardashevskiy <aik@xxxxxxx>
> > Cc: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx>
> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
>
> Interesting bit of emulation. Only real question I have
> is whether you can switch from platform devices to faux bus?
[..]
>
> > +static struct platform_device *devsec_tsm;
> > +
> > +static int __init devsec_tsm_init(void)
> > +{
>
> Could this use the faux bus stuff or does it need to be a platform
> device for some reason? That support may well have crossed with this work.
Yes, this was conceived before that existed, but it is a perfect fit for
what I need here. Switched.
