Messages in this thread | | | Subject | Re: [PATCHv1 3/4] dt-bindings: fpga: add authenticate-fpga-config property | From | Richard Gong <> | Date | Wed, 18 Nov 2020 07:38:31 -0600 |
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On 11/17/20 11:47 PM, Xu Yilun wrote: > On Tue, Nov 17, 2020 at 09:39:55AM -0600, Richard Gong wrote: >> >> >> On 11/16/20 8:24 PM, Xu Yilun wrote: >>> On Mon, Nov 16, 2020 at 08:14:52AM -0600, Richard Gong wrote: >>>> >>>> Hi Yilun, >>>> >>>> On 11/15/20 8:47 PM, Xu Yilun wrote: >>>>> On Sun, Nov 15, 2020 at 11:21:06AM -0800, Moritz Fischer wrote: >>>>>> Hi Richard, >>>>>> >>>>>> On Thu, Nov 12, 2020 at 12:06:42PM -0600, richard.gong@linux.intel.com wrote: >>>>>>> From: Richard Gong <richard.gong@intel.com> >>>>>>> >>>>>>> Add authenticate-fpga-config property for FPGA bitstream authentication. >>>>>>> >>>>>>> Signed-off-by: Richard Gong <richard.gong@intel.com> >>>>>>> --- >>>>>>> Documentation/devicetree/bindings/fpga/fpga-region.txt | 1 + >>>>>>> 1 file changed, 1 insertion(+) >>>>>>> >>>>>>> diff --git a/Documentation/devicetree/bindings/fpga/fpga-region.txt b/Documentation/devicetree/bindings/fpga/fpga-region.txt >>>>>>> index e811cf8..7a512bc 100644 >>>>>>> --- a/Documentation/devicetree/bindings/fpga/fpga-region.txt >>>>>>> +++ b/Documentation/devicetree/bindings/fpga/fpga-region.txt >>>>>>> @@ -187,6 +187,7 @@ Optional properties: >>>>>>> - external-fpga-config : boolean, set if the FPGA has already been configured >>>>>>> prior to OS boot up. >>>>>>> - encrypted-fpga-config : boolean, set if the bitstream is encrypted >>>>>>> +- authenticate-fpga-config : boolean, set if do bitstream authentication >>>>>> It is unclear to me from the description whether this entails >>>>>> authentication + reconfiguration or just authentication. >>>>>> >>>>>> If the latter is the case this should probably be described as such. >>>>> >>>>> If it is just authentication, do we still need to disable bridges in >>>>> fpga_region_program_fpga? >>>>> >>>> >>>> Yes. >>>> >>>> Except for the actual configuration of the device, the authentication >>>> feature is the same as FPGA configuration. >>> >>> FPGA Bridges gate bus signals between a host and FPGA. So the FPGA >>> region could not be accessed by host when doing configuration. But for >>> this authentication, we are just writing the flash, we don't actually >>> touch the FPGA soft logic. The host should still be able to operate on >>> the old logic before reboot, is it? >>> >> Yes, it's feasible in theory but doesn't make much sense in practice. I >> prefer to keep fpga_region_program_fpga() unchanged. > > I'm thinking of the case of inband reprograming, that the QSPI flash > controller itself is embedded in FPGA soft logic, then maybe host still > need to access FPGA on authentication.
We can decide whether we should update fpga_region_program_fpga() function when you update for inband reprogramming case.
Regards, Richard > > Thanks, > Yilun > >>>> >>>>> I'm wondering if the FPGA functionalities could still be working when >>>>> the authenticating is ongoing, or when the authenticating is failed. >>>>> >>>> >>>> >>>> >>>>> Thanks, >>>>> Yilun >>>>> >>>>>> >>>>>>> - region-unfreeze-timeout-us : The maximum time in microseconds to wait for >>>>>>> bridges to successfully become enabled after the region has been >>>>>>> programmed. >>>>>>> -- >>>>>>> 2.7.4 >>>>>>> >>>>>> >>>>>> Thanks
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