Re: [RFC V1 00/14] precreate phase

[Steven Sistare <steven.sistare@oracle.com>]

On 10/17/2024 11:53 AM, Peter Xu wrote:
> On Thu, Oct 17, 2024 at 11:19:51AM -0400, Steven Sistare wrote:
>> On 10/17/2024 11:14 AM, Steve Sistare wrote:
>>> Define a new qemu initialization phase called 'precreate' which occurs
>>> before most backends or devices have been created.  The only exception
>>> is monitor and qtest devices and their associated chardevs.
>>>
>>> QEMU runs in the main loop during this phase.  Monitor connections are
>>> active and can receive migration configuration commands.  QEMU starts
>>> listening on the normal migration URI during this phase, which can come
>>> from either the QEMU command line or from a migrate_incoming command.
>>> Thus the user can issue query-migrate to get the socket-address for
>>> dynamically allocated port numbers during precreate.
>>>
>>> In this series QEMU passes through and does not linger in the precreate
>>> phase, and the user sees no change in behavior.  The cpr-transfer series
>>> will linger in the phase for an incoming CPR operation, and exit the phase
>>> when the migrate command is send to source QEMU and causes destination QEMU
>>> to read CPR state.
>>
>> Hi Peter, I rebased the cpr-transfer series on precreate.  The
>> cpr-transfer migration-test now works.  Do you want to see cpr-transfer
>> V3 now, or wait until we get feedback on precreate?  The only significant
>> change is that I deleted the HUP synchronization, and I post an async
>> listen for the incoming cpr-uri connection.
> 
> Maybe you can still send it, because I remember there're some other
> discussion that may not settled yet (e.g. how anon-memfd is applied, iirc),
> then it can be reviewed and discussed concurrently when proper with the
> precreate series.

For now I'll reply to the open email threads for cpr-transfer V2.

- Steve