Linux-libre-4.15 and the NVMe module

[Mark H Weaver <mhw@netris.org>]

Hello Guix,

I've pushed a new 'kernel-updates' branch that includes the update to
linux-libre-4.15, and asked Hydra to build it.  However, I haven't yet
pushed this to 'master' because of a complication.

At present, all of our kernel configurations have CONFIG_BLK_DEV_NVME=m
which results in an "nvme.ko" module, and this module is included in the
list of modules to be copied to our 'base-initrd' and loaded during
early boot.

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.

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.

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.

Any comments on this approach?  Other suggestions?

      Mark