Re: [PATCH v4 00/25] migration: Improve error reporting

["Cédric Le Goater" <clg@redhat.com>]

On 3/12/24 08:16, Cédric Le Goater wrote:
> On 3/11/24 21:24, Peter Xu wrote:
>> On Fri, Mar 08, 2024 at 04:15:08PM +0800, Peter Xu wrote:
>>> On Wed, Mar 06, 2024 at 02:34:15PM +0100, Cédric Le Goater wrote:
>>>> * [1-4] already queued in migration-next.
>>>>    migration: Report error when shutdown fails
>>>>    migration: Remove SaveStateHandler and LoadStateHandler typedefs
>>>>    migration: Add documentation for SaveVMHandlers
>>>>    migration: Do not call PRECOPY_NOTIFY_SETUP notifiers in case of error
>>>> * [5-9] are prequisite changes in other components related to the
>>>>    migration save_setup() handler. They make sure a failure is not
>>>>    returned without setting an error.
>>>>    s390/stattrib: Add Error** argument to set_migrationmode() handler
>>>>    vfio: Always report an error in vfio_save_setup()
>>>>    migration: Always report an error in block_save_setup()
>>>>    migration: Always report an error in ram_save_setup()
>>>>    migration: Add Error** argument to vmstate_save()
>>>>
>>>> * [10-15] are the core changes in migration and memory components to
>>>>    propagate an error reported in a save_setup() handler.
>>>>
>>>>    migration: Add Error** argument to qemu_savevm_state_setup()
>>>>    migration: Add Error** argument to .save_setup() handler
>>>>    migration: Add Error** argument to .load_setup() handler
>>>
>>> Further queued 5-12 in migration-staging (until here), thanks.
>>
>> Just to keep a record: due to the virtio failover test failure and the
>> other block migration uncertainty in patch 7 (in which case we may want to
>> have a fix on sectors==0 case), I unqueued this chunk for 9.0.
> 
> ok. I will ask the block folks for help to understand if sectors==0
> is also an error in the save_setup context. May be  we can still
> merge these in 9.0 cycle.

I discussed with Kevin and sectors==0 is not an error case, the loop
should simply continue. That said, commit 66db46ca83b8 ("migration:
Deprecate block migration") would let us remove all that code in
the next cycle which is even simpler.

Thanks,

C.