Re: [PATCH v9 9/9] drivers/node: Show in sysfs node's crypto capabilities

[Greg KH]

On Mon, Jul 04, 2022 at 10:58:33AM -0300, Martin Fernandez wrote:
> Show in each node in sysfs if its memory is able to do be encrypted by
> the CPU; on EFI systems: if all its memory is marked with
> EFI_MEMORY_CPU_CRYPTO in the EFI memory map.
> 
> Signed-off-by: Martin Fernandez <martin.fernandez@xxxxxxxxxxxxx>
> ---
>  Documentation/ABI/testing/sysfs-devices-node | 10 ++++++++++
>  drivers/base/node.c                          | 10 ++++++++++
>  2 files changed, 20 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-devices-node
> 
> diff --git a/Documentation/ABI/testing/sysfs-devices-node b/Documentation/ABI/testing/sysfs-devices-node
> new file mode 100644
> index 000000000000..0e95420bd7c5
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-devices-node
> @@ -0,0 +1,10 @@
> +What:		/sys/devices/system/node/nodeX/crypto_capable
> +Date:		April 2022
> +Contact:	Martin Fernandez <martin.fernandez@xxxxxxxxxxxxx>
> +Users:		fwupd (https://fwupd.org)
> +Description:
> +		This value is 1 if all system memory in this node is
> +		capable of being protected with the CPU's memory
> +		cryptographic capabilities.  It is 0 otherwise.
> +		On EFI systems the node will be marked with
> +		EFI_MEMORY_CPU_CRYPTO.

Where will such a node be "marked"?  I do not understand this last
sentence, sorry, can you please reword this?

And why is EFI an issue here at all?

thanks,

greg k-h