Re: Linux-libre-4.15 and the NVMe module

[Danny Milosavljevic <dannym@scratchpost.org>]

Hi Mark,

On Mon, 29 Jan 2018 09:18:17 -0500
Mark H Weaver <mhw@netris.org> wrote:

> Unfortunately, it seems that in linux-libre-4.15, we must now have
> CONFIG_BLK_DEV_NVME=y (built-in) if we wish to keep CONFIG_NVM=y
> (Open-Channel SSD target support), which we've had enabled in our kernel
> configurations since 4.4.  CONFIG_NVM cannot be made modular, and in
> 4.15 it now depends on CONFIG_BLK_DEV_NVME=y.

I wonder whether that's a regression or on purpose...

> Since I don't see a nice way in our current 'base-initrd' implementation
> to conditionally include "nvme.ko" depending on the kernel
> configuration, I simply removed "nvme.ko" from the list of modules, and
> changed all of our kernel configurations to have CONFIG_BLK_DEV_NVME=y.

I think that's fine for the time being.

That said, it would be nice if we extended our base-initrd implementation to
take a list of modules to try to copy, and to skip each which doesn't exist.

It would make the initrds more reusable and I don't see a downside if we
supported both this new list of modules and the existing list of modules.

> While I was at it, I updated our older kernel configurations to the
> current point releases, using "make oldconfig".  My main motivation for
> doing this was to explicitly show in our config files that we've enabled
> the mitigations for meltdown and spectre.

Good idea.