Re: [V2 4/6] platform/x86: Add Intel Software Defined Silicon driver

From: Leon Romanovsky <leon@kernel.org>
To: "David E. Box" <david.e.box@linux.intel.com>
Cc: lee.jones@linaro.org, hdegoede@redhat.com, bhelgaas@google.com,
	gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com,
	srinivas.pandruvada@intel.com, shuah@kernel.org,
	mgross@linux.intel.com, linux-kernel@vger.kernel.org,
	platform-driver-x86@vger.kernel.org,
	linux-kselftest@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: [V2 4/6] platform/x86: Add Intel Software Defined Silicon driver
Date: Wed, 8 Dec 2021 09:14:47 +0200	[thread overview]
Message-ID: <YbBbZ+JMk9eEgNKl@unreal> (raw)
In-Reply-To: <20211207171448.799376-5-david.e.box@linux.intel.com>

On Tue, Dec 07, 2021 at 09:14:46AM -0800, David E. Box wrote:
> Intel Software Defined Silicon (SDSi) is a post manufacturing mechanism for
> activating additional silicon features. Features are enabled through a
> license activation process.  The SDSi driver provides a per socket, sysfs
> attribute interface for applications to perform 3 main provisioning
> functions:
> 
> 1. Provision an Authentication Key Certificate (AKC), a key written to
>    internal NVRAM that is used to authenticate a capability specific
>    activation payload.
> 
> 2. Provision a Capability Activation Payload (CAP), a token authenticated
>    using the AKC and applied to the CPU configuration to activate a new
>    feature.
> 
> 3. Read the SDSi State Certificate, containing the CPU configuration
>    state.
> 
> The operations perform function specific mailbox commands that forward the
> requests to SDSi hardware to perform authentication of the payloads and
> enable the silicon configuration (to be made available after power
> cycling).
> 
> The SDSi device itself is enumerated as an auxiliary device from the
> intel_vsec driver and as such has a build dependency on CONFIG_INTEL_VSEC.
> 
> Link: https://github.com/intel/intel-sdsi
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> Reviewed-by: Mark Gross <markgross@kernel.org>
> ---
> V2
>   - Use sysfs_emit() in guid_show()
>   - Fix language in ABI, suggested by Bjorn
>   - Fix wrong directory name in ABI doc

<...>

> @@ -0,0 +1,77 @@
> +What:		/sys/bus/auxiliary/devices/intel_vsec.sdsi.X

<...>

> +static const struct auxiliary_device_id sdsi_aux_id_table[] = {
> +	{ .name = "intel_vsec.sdsi" },

Are you sure that this sysfs is correct?

Auxiliary bus set device name as a combination of module name plus suffix.

  172 int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname)
  173 {
  174         struct device *dev = &auxdev->dev;
  175         int ret;
 ....
  181
  182         ret = dev_set_name(dev, "%s.%s.%d", modname, auxdev->name, auxdev->id);

Thanks