[PATCH v13 0/4] add debugfs to migration driver

[Alex Williamson]

On Wed, 16 Aug 2023 17:42:01 +0800
liulongfang <liulongfang at huawei.com> wrote:

> Add a debugfs function to the migration driver in VFIO to provide
> a step-by-step test function for the migration driver.
> 
> When the execution of live migration fails, the user can view the
> status and data during the migration process separately from the
> source and the destination, which is convenient for users to analyze
> and locate problems.
> 
> Changes v12 -> v13
> 	Solve the problem of open and close competition to debugfs.

Hi,

I'm not sure if the new To: list is a mistake or if this is an appeal
to a different set of maintainers for a more favorable response than
previous postings[1], but kvm at vger.kernel.org remains the list for this
driver, which is under the perview of vfio [adding the correct list and
co-maintainer].

I believe there is still a concern whether this is a valid and
worthwhile debugfs interface.  It has been suggested that much of what
this provides could be done through userspace drivers to exercise the
migration interfaces and/or userspace debugging techniques to examine
the device migration data.  I haven't seen a satisfactory conclusion
for these comments yet.

I think we have general consensus that the first couple patches are ok
and useful, exposing the migration state generically and supporting a
minor cleanup within the hisi_acc driver.  However, the new approach to
try to lock the device with igate is certainly not the correct (igate
is used for serializing interrupt configuration) and the proposed
hisi_acc specific debugfs interfaces themselves are not settled.
Thanks,

Alex

[1]https://lore.kernel.org/all/20230728072104.64834-1-liulongfang@huawei.com/