ACK/cmnt: [SRU][F][PATCH 0/1] Support/enhancement of NVMe IPL (LP: 1902179)

[Frank Heimes]

Hi Kleber,
I already did regression testing on our z13 based on the test kernel that
I've built - just to make sure that it does not have a bad impact on
systems that use disks other than NVMe (like DASD and zFCP).
Since we do not have NVMe disks in our system (and btw. a never Z
generation is needed anyway) this definitely needs to be tested by IBM.
Hence me sharing the test kernel and of course another test is needed (and
was already raised) to verify the kernel when it lands in -proposed.
It will be tested in a similar way like the NVMe support in groovy was once
tested - (manually updating kernel, running zipl bootloader, reboot, test
env., calling reipl, rebooting, test env., etc.) - so this test procedure
is known by the IBM test engineers.

Bye and thanks for the ACK, Frank




On Wed, Nov 4, 2020 at 9:46 AM Kleber Souza <kleber.souza at canonical.com>
wrote:

> On 03.11.20 19:31, frank.heimes at canonical.com wrote:
> > BugLink: https://bugs.launchpad.net/bugs/1902179
> >
> > SRU Justification:
> >
> > [Impact]
> >
> > * The base for being able to IPL (boot) NVMe devices on s390x was
> introduced with kernel 5.8.
> >
> > * This got now requested (for hardware enablement reasons) for Ubuntu
> 20.04 LTS as well.
> >
> > * On top a brand new commit got upstream accepted that introduces
> support for NVMe IPL kernel parameters, which is not yet in groovy.
> >
> > [Fix]
> >
> > * cherry pick of commit 3737e8ee4f2fc7e77994d1a8bd618a9dda5a5514
> 3737e8ee4f2f "s390: nvme ipl"
> >
> > * cherry pick of commit 23a457b8d57dc8d0cc1dbd1882993dd2fcc4b0c0
> 23a457b8d57d "s390: nvme reipl"
> >    does not apply cleanly, hence the following backport:
> >
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1902179/+attachment/5430310/+files/0002-s390-nvme-reipl.patch
>
> Although this backport has been provided by IBM, there's no information on
> the bug
> if/how this backport has been tested at all. It would be good to request
> IBM to
> verify this fix once the kernels hit -proposed.
>
> Apart from that, and the comment on patch 3/3, the patches and the request
> look good to me.
>
> Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>
>
> >
> > * cherry pick of commit d9f12e48d08ec08ace574050a838e001e442ee38
> d9f12e48d08e "s390/ipl: support NVMe IPL kernel parameters"
> >
> > [Test Case]
> >
> > * IBM z15 or LinuxONE III hardware is needed with an NVMe device
> attached to a LPAR.
> >
> > * Install the patched kernel on focal/20.04 installation and make sure
> that zipl re-ran (the patched version of zipl with the s390-tools commit
> mentioned in this LP bug - or take the s390-tools version for groovy for
> testing purposes).
> >
> > * If everything is in place (means patched kernel, as well as patched
> s390-tools/zipl) an installation from scratch on an NVMe devices should be
> possible - in case everything needed landed on an updated image.
> >    With the 20.04.2 image that should be the case.
> >
> > [Regression Potential]
> >
> > * There is a certain regression risk with these patches, because:
> >
> > * the 'zipl' (s390x-specific) boot-loader is touched
> >
> > * if something is wrong there, in worst-case systems where the modified
> zipl ran may no longer be bootable!
> >
> > * The modifications are targetted towards nvme devices ('blkext'
> driver), but they are closely related to zFCP devices and share some code
> parts,
> >
> > * hence in worst case they could have an impact on zFCP devices, too.
> >
> > * But this is very unlikely, since a (largely) separate IPL type 'nvme'
> got introduced and NVMe ipl is handled in separate case statements and
> functions.
> >
> > * The patches are all upstream accepted (the first two with 5.8, that
> last with v5.10-rc1, hence the latter one is as of today in linux-next).
> >
> > * A patched focal kernel was build and shared for further testing. I did
> some regression testing with the patched kernel on non-NVMe systems - the
> NVMe based tests need to be done by IBM (due to the lack of hardware).
> >
> > * All modifications are limited to the s390x architecture and there
> again to the unique way of booting aka IPL (arch/s390/include/asm/ipl.h,
> arch/s390/include/uapi/asm/ipl.h, arch/s390/kernel/ipl.c and
> arch/s390/boot/ipl_parm.c).
> >
> > [Other]
> >
> > * The general NVMe ipl (boot) functionality in given with 3737e8ee4f2f
> "s390: nvme ipl" and 23a457b8d57d "s390: nvme reipl" and is already proven
> to work with groovy.
> >
> > * New for groovy AND focal is only "s390/ipl: support NVMe IPL kernel
> parameters".
> >
> > * The entire set of commits/patches is only new for focal.
> >
> > * The SRU for SRUing "s390/ipl: support NVMe IPL kernel parameters" to
> groovy/20.10 was handled by a separate request.
> >
> > Alexander Egorenkov (1):
> >    s390/ipl: support NVMe IPL kernel parameters
> >
> > Jason J. Herne (2):
> >    s390: nvme ipl
> >    s390: nvme reipl
> >
> >   arch/s390/boot/ipl_parm.c        |  31 +++--
> >   arch/s390/include/asm/ipl.h      |  11 ++
> >   arch/s390/include/uapi/asm/ipl.h |  25 ++++
> >   arch/s390/kernel/ipl.c           | 209 +++++++++++++++++++++++++++++++
> >   4 files changed, 268 insertions(+), 8 deletions(-)
> >
>
>
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