Re: [PATCH v2 1/1] dm-inlinecrypt: add support for hardware-wrapped keys

[Milan Broz <gmazyland@gmail.com>]

On 5/16/26 1:50 PM, Linlin Zhang wrote:
> Add support for hardware-wrapped encryption keys to the
> dm-inlinecrypt target.
> 
> Introduce a new parameter <is_wrappedkey> to indicate whether
> the provided key is a raw key or a hardware-wrapped key. Based
> on this flag, the appropriate blk-crypto key type is selected
> when initializing the key.
> 
> This allows dm-inlinecrypt to work with hardware that requires
> keys to be wrapped and managed by the underlying inline
> encryption engine.
> 
> Update the target argument parsing accordingly and pass the
> key type to blk_crypto_init_key(). Documentation is also
> updated to reflect the new parameter and usage.
> 
> Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
> ---
>   .../device-mapper/dm-inlinecrypt.rst          | 10 ++-
>   drivers/md/dm-inlinecrypt.c                   | 71 +++++++++++--------
>   2 files changed, 50 insertions(+), 31 deletions(-)
> 
> diff --git a/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst b/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst
> index c71e600efb76..3a4ce2c5f228 100644
> --- a/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst
> +++ b/Documentation/admin-guide/device-mapper/dm-inlinecrypt.rst
> @@ -10,7 +10,7 @@ https://docs.kernel.org/block/inline-encryption.html
>   
>   Parameters::
>   
> -	      <cipher> <key> <iv_offset> <device path> \
> +	      <cipher> <key> <is_wrappedkey> <iv_offset> <device path> \
>   	      <offset> [<#opt_params> <opt_params>]

Please use optional parameter.
Adding mandatory field will introduce unnecessary incompatibility with dm-crypt mappings.
(The idea was that you can simply switch "crypt" to "inlinecrypt" for raw keys.)

I would probably just add "hw-wrapped" or "keytype=raw|hw-wrapped" optional argument
(with raw as default, so no need so specify it).

IOW the mapping will look like this (1 is number of optional parameters):

    <cipher> <key> <iv_offset> <device path> <offset> 1 hw-wrapped
or
    <cipher> <key> <iv_offset> <device path> <offset> 1 keytype=hw-wrapped

The second option will allow to add new key type much easier.

Please check how other targets implement it, some dm-crypt examples
https://gitlab.com/cryptsetup/cryptsetup/-/wikis/DMCrypt

Thanks,
Milan