On Wed, Aug 04, 2021 at 05:12:41PM +0200, Greg KH wrote: > On Wed, Aug 04, 2021 at 07:58:34AM -0700, Moritz Fischer wrote: > > On Wed, Aug 04, 2021 at 09:37:45AM +0200, Greg KH wrote: > > > On Tue, Aug 03, 2021 at 12:02:24PM -0700, Russ Weight wrote: > > > > > > > > > > > > On 8/2/21 10:49 PM, Greg KH wrote: > > > > >> If the request_firmware() implementation is not acceptable, then would > > > > >> you agree that an IOCTL implementation is our best option? > > > > > There is no difference in the end between using an ioctl, or a sysfs > > > > > file, to provide the filename of your firmware, don't get hung up on > > > > > that. > > > > > > > > I meant to suggest that passing file data (not a filename) through an > > > > IOCTL might be better for this use case than trying to use request_firmware. > > > > We have to, somehow, allow the user to point us to the desired image > > > > data (which could be a root-entry-hash, or an FPGA image). We can't > > > > really use a fixed filename modified by device version as many of > > > > the devices do. > > > > > > Ah, yes, a "normal" write command might be best for this as that can be > > > properly containerized and controlled. > > > > > > > > By providing a "filename", you are going around all of the namespace and > > > > > other "container" protection that the kernel provides, and allowing > > > > > processes to potentially load files that are normally outside of their > > > > > scope to the hardware. If you are willing to allow that security > > > > > "escape", wonderful, but you better document the heck out of it and > > > > > explain why this is allowed for your special hardware and use case. > > > > > > > > > > As you are expecting this to work "in the cloud", I do not think that > > > > > the operators of such hardware are really going to be all that happy to > > > > > see this type of interface given these reasons. > > > > > > > > > > What is wrong with the current fpga firmware api that somehow is lacking > > > > > for your special hardware, that other devices do not have to worry > > > > > about? > > > > The existing framework wants to update the live image in the FPGA, > > > > whereas for this device, we are passing signed data to BMC firmware > > > > which will store it in FLASH to be loaded on a subsequent boot of > > > > the card. > > > > > > > > The existing framework needs to manage FPGA state, whereas for this > > > > device, it is just a transfer of signed data. We also have to handle > > > > a total transfer/authentication time of up to 45 minutes, so we are > > > > using a kernel worker thread for the update. > > > > > > > > Perhaps the name, fpga security manager, is wrong? Maybe something > > > > like fpga_sec_image_xfer is better? > > > > > > It does not sound like this has anything to do with "security", and > > > rather is just a normal firmware upload, so "fpga_image_upload()" > > > perhaps? > > > > I had originally suggested 'load' and 'persist' or 'load' and 'update or > > something of that sort. > > > > Taking one step back, maybe the case could be made for a generic > > 'persistent firmware' update framework that addresses use-cases that > > require updating firmware that may take extended periods of time. > > There should not be a problem with using the existing firmware layer for > images that take long periods of time, as long as you are not wanting to > see any potential progress :) > > So how about just adding anything missing to the existing firmware > subsystem. It's attempting to handle all use cases already, if it is > missing one, no harm in adding more options there... Even better if we can do that. It would have a limited overlap with existing functionality, though. - Moritz
