Re: [PATCH 1/2] fpga: mgr: Adds secure BitStream loading support

[Moritz Fischer]

Hi Nava,

On Thu, Jan 21, 2021 at 09:17:10PM -0800, Moritz Fischer wrote:
> On Mon, Jan 18, 2021 at 08:20:57AM +0530, Nava kishore Manne wrote:
> > This commit adds secure flags to the framework to support
> > secure BitStream Loading.
> > 
> > Signed-off-by: Nava kishore Manne <nava.manne@xxxxxxxxxx>
> > ---
> >  drivers/fpga/of-fpga-region.c | 10 ++++++++++
> >  include/linux/fpga/fpga-mgr.h | 12 ++++++++++++
> >  2 files changed, 22 insertions(+)
> > 
> > diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
> > index e405309baadc..3a5eb4808888 100644
> > --- a/drivers/fpga/of-fpga-region.c
> > +++ b/drivers/fpga/of-fpga-region.c
> > @@ -228,6 +228,16 @@ static struct fpga_image_info *of_fpga_region_parse_ov(
> >  	if (of_property_read_bool(overlay, "encrypted-fpga-config"))
> >  		info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;
> >  
> > +	if (of_property_read_bool(overlay, "userkey-encrypted-fpga-config"))
> > +		info->flags |= FPGA_MGR_USERKEY_ENCRYPTED_BITSTREAM;
> 
> Can this just be encrypted-fpga-config/FPGA_MGR_ENCRYPTED?
> > +
> > +	if (of_property_read_bool(overlay, "ddrmem-authenticated-fpga-config"))
> > +		info->flags |= FPGA_MGR_DDR_MEM_AUTH_BITSTREAM;
> > +
> > +	if (of_property_read_bool(overlay,
> > +				  "securemem-authenticated-fpga-config"))
> > +		info->flags |= FPGA_MGR_SECURE_MEM_AUTH_BITSTREAM;
Shouldn't all these get binding docs? I remember Richard adding
authentication support for an Intel platform, too and I'd like to avoid
adding random bindings per vendor.

Would it be possible to have an 'authentication method / type' that is more
extensible with different methods maybe?

> > +
> >  	if (!of_property_read_string(overlay, "firmware-name",
> >  				     &firmware_name)) {
> >  		info->firmware_name = devm_kstrdup(dev, firmware_name,
> > diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> > index 2bc3030a69e5..2f7455a60666 100644
> > --- a/include/linux/fpga/fpga-mgr.h
> > +++ b/include/linux/fpga/fpga-mgr.h
> > @@ -67,12 +67,24 @@ enum fpga_mgr_states {
> >   * %FPGA_MGR_BITSTREAM_LSB_FIRST: SPI bitstream bit order is LSB first
> >   *
> >   * %FPGA_MGR_COMPRESSED_BITSTREAM: FPGA bitstream is compressed
> > + *
> > + * %FPGA_MGR_USERKEY_ENCRYPTED_BITSTREAM: indicates bitstream is encrypted with
> > + *                                        user key
> > + *
> > + * %FPGA_MGR_DDR_MEM_AUTH_BITSTREAM: do bitstream authentication using DDR
> > + *                                   memory if supported
> > + *
> > + * %FPGA_MGR_SECURE_MEM_AUTH_BITSTREAM: do bitstream authentication using secure
> > + *                                      memory if supported
> >   */
> >  #define FPGA_MGR_PARTIAL_RECONFIG	BIT(0)
> >  #define FPGA_MGR_EXTERNAL_CONFIG	BIT(1)
> >  #define FPGA_MGR_ENCRYPTED_BITSTREAM	BIT(2)
> >  #define FPGA_MGR_BITSTREAM_LSB_FIRST	BIT(3)
> >  #define FPGA_MGR_COMPRESSED_BITSTREAM	BIT(4)
> > +#define FPGA_MGR_USERKEY_ENCRYPTED_BITSTREAM	BIT(5)
> > +#define FPGA_MGR_DDR_MEM_AUTH_BITSTREAM		BIT(6)
> > +#define FPGA_MGR_SECURE_MEM_AUTH_BITSTREAM	BIT(7)
> >  
> >  /**
> >   * struct fpga_image_info - information specific to a FPGA image
> > -- 
> > 2.18.0
> > 
> 
> Thanks,
> Moritz
Moritz