Re: [dpdk-dev] [PATCH v3] igb_uio: fail and log if kernel lock down is enabled

[Neil Horman <nhorman@tuxdriver.com>]

On Thu, May 17, 2018 at 02:26:12PM +0100, Ferruh Yigit wrote:
> On 5/17/2018 12:34 PM, Neil Horman wrote:
> > On Wed, May 16, 2018 at 03:42:20PM +0100, Ferruh Yigit wrote:
> >> When EFI secure boot is enabled, it is possible to lock down kernel and
> >> prevent accessing device BARs and this makes igb_uio unusable.
> >>
> >> Lock down patches are not part of the vanilla kernel but they are
> >> applied and used by some distros already [1].
> >>
> >> It is not possible to fix this issue, but intention of this patch is to
> >> detect and log if kernel lock down enabled and don't insert the module
> >> for that case.
> >>
> >> The challenge is since this feature enabled by distros, they have
> >> different config options and APIs for it. This patch is done based on
> >> Fedora and Ubuntu kernel source, may needs to add more distro specific
> >> support.
> >>
> > I still need to ask, what exactly is the error you're seeing with inserting the
> > uio module?  The lockdown patch set restricts BAR address changes, but via paths
> > acessible from user space, igbuio should still insert and initalize just fine
> > (or so it would seem to me).  Why not fix this by detecting the problem during
> > the user space library initalization, where you can do so via a standard method
> > that works accross distributions?
> 
> I have seen you comment on other thread, this v3 was just to fix a silly
> mistake, lets continue discussion in other thread.
> 
Copy that, thank you
Neil