Re: Linux-libre-4.15 and the NVMe module

[ng0@n0.is]

Hi,

On Mon, 29 Jan 2018, Mark H Weaver <mhw@netris.org> wrote:
> 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.

Oh, good that you've looked deeper into this. I planned to when
the rc's started showing this problem but didn't really follow-up
to it.

> 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
>
>

I think in general it's okay. I'm still rebuilding my server with
the patches taken from your branch. I suspect not to run into any
problems with it, and skipping the commits they looked good to me.

Of course I can only test for x86, not i686 or aarch64

Thanks!
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