[RFC PATCH 00/11] hw/nvme: reimplement all multi-aio commands with custom aiocbs

[Klaus Jensen <its@irrelevant.dk>]

From: Klaus Jensen <k.jensen@samsung.com>

This series reimplements flush, dsm, copy, zone reset and format nvm to
allow cancellation. I posted an RFC back in March ("hw/block/nvme:
convert ad-hoc aio tracking to aiocb") and I've applied some feedback
from Stefan and reimplemented the remaining commands.

The basic idea is to define custom AIOCBs for these commands. The custom
AIOCB takes care of issuing all the "nested" AIOs one by one instead of
blindly sending them off simultaneously without tracking the returned
aiocbs.

I've kept the RFC since I'm still new to using the block layer like
this. I was hoping that Stefan could find some time to look over this -
this is a huge series, so I don't expect non-nvme folks to spend a large
amount of time on it, but I would really like feedback on my approach in
the reimplementation of flush and format. Those commands are special in
that may issue AIOs to multiple namespaces and thus, to multiple block
backends. Since this device does not support iothreads, I've opted for
simply always returning the main loop aio context, but I wonder if this
is acceptable or not. It might be the case that this should contain an
assert of some kind, in case someone starts adding iothread support.

Klaus Jensen (11):
  hw/nvme: reimplement flush to allow cancellation
  hw/nvme: add nvme_block_status_all helper
  hw/nvme: reimplement dsm to allow cancellation
  hw/nvme: save reftag when generating pi
  hw/nvme: remove assert from nvme_get_zone_by_slba
  hw/nvme: use prinfo directly in nvme_check_prinfo and nvme_dif_check
  hw/nvme: add dw0/1 to the req completion trace event
  hw/nvme: reimplement the copy command to allow aio cancellation
  hw/nvme: reimplement zone reset to allow cancellation
  hw/nvme: reimplement format nvm to allow cancellation
  Partially revert "hw/block/nvme: drain namespaces on sq deletion"

 hw/nvme/nvme.h       |   10 +-
 include/block/nvme.h |    8 +
 hw/nvme/ctrl.c       | 1861 ++++++++++++++++++++++++------------------
 hw/nvme/dif.c        |   64 +-
 hw/nvme/trace-events |   21 +-
 5 files changed, 1102 insertions(+), 862 deletions(-)

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2.31.1