On Mon, Apr 11, 2022 at 08:47:41AM -0300, Jason Gunthorpe wrote: > On Sun, Apr 10, 2022 at 07:11:23PM +0200, Lukas Wunner wrote: > > On Thu, Apr 07, 2022 at 11:25:26AM -0300, Jason Gunthorpe wrote: > > > On Thu, Apr 07, 2022 at 01:18:45PM +0200, Lino Sanfilippo wrote: > > > > Currently it is not possible to set the tpm chips reset state from within > > > > the driver. This is problematic if the chip is still in reset after the > > > > system comes up. This may e.g. happen if the reset line is pulled into > > > > reset state by a pin configuration in the device tree. > > > > > > This kind of system is badly misdesigned. > > > > > > TPM PCRs fundementally cannot work if the TPM reset line is under > > > software control. > > > > Not every system which incorporates a TPM wants to use or is even capable > > of measuring software state of any kind or perform secure boot. > > > > Those systems may merely want to use the TPM to store key material. > > Then maybe the TPM driver should make it clear somehow that the PCRs > don't work in these systems. > > It is really dangerous to add capabilities like this that should > never, ever be used in sanely designed systems. > > Jason I agree. That niche should do the bad things with oot patches. BR, Jarkko
