Re: [PATCH-for-9.1 v2 2/3] migration: Remove RDMA protocol handling

From: Peter Xu <peterx@redhat.com>
To: Thomas Huth <thuth@redhat.com>
Cc: "Fabiano Rosas" <farosas@suse.de>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>,
	qemu-devel@nongnu.org, "Yuval Shaia" <yuval.shaia.ml@gmail.com>,
	"Kevin Wolf" <kwolf@redhat.com>,
	"Prasanna Kumar Kalever" <prasanna.kalever@redhat.com>,
	"Cornelia Huck" <cohuck@redhat.com>,
	"Michael Roth" <michael.roth@amd.com>,
	"Li Zhijian" <lizhijian@fujitsu.com>,
	"Prasanna Kumar Kalever" <prasanna4324@gmail.com>,
	integration@gluster.org, "Paolo Bonzini" <pbonzini@redhat.com>,
	qemu-block@nongnu.org, "Daniel P. Berrangé" <berrange@redhat.com>,
	devel@lists.libvirt.org, "Hanna Reitz" <hreitz@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Eric Blake" <eblake@redhat.com>,
	"Song Gao" <gaosong@loongson.cn>,
	"Marc-André Lureau" <marcandre.lureau@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Wainer dos Santos Moschetta" <wainersm@redhat.com>,
	"Beraldo Leal" <bleal@redhat.com>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Yu Zhang" <yu.zhang@ionos.com>
Subject: Re: [PATCH-for-9.1 v2 2/3] migration: Remove RDMA protocol handling
Date: Thu, 28 Mar 2024 15:04:52 -0400	[thread overview]
Message-ID: <ZgW_VF1YUEcefHNw@x1n> (raw)
In-Reply-To: <a6677385-07c7-4b74-bd78-b14c2e80f107@redhat.com>

On Thu, Mar 28, 2024 at 04:22:27PM +0100, Thomas Huth wrote:
> Since e9a54265f5 was not very clear about rdma migration code, should we
> maybe rather add a separate deprecation note for the migration part, and add
> a proper warning message to the migration code in case someone tries to use
> it there, and then only remove the rdma migration code after two more
> releases?

Definitely a valid option to me.

So far RDMA isn't covered in tests (actually same to COLO, and I wonder our
position of COLO too in this case..), so unfortunately we don't even know
when it'll break just like before.

From other activities that I can see when new code comes, maintaining RDMA
code should be fairly manageable so far (and whoever will write new rdma
codes in those two releases will also need to take the maintainer's
role). We did it for those years, and we can keep that for two more
releases. Hopefully that can ring a louder alarm to the current users with
such warnings, so that people can either stick with old binaries, or invest
developer/test resources to the community.

Thanks,

-- 
Peter Xu