Re: [Qemu-devel] [PATCH] migration: notify runstate immediately before vcpu stops

[Peter Xu <zhexu@redhat.com>]

On Tue, Jul 16, 2019 at 03:29:19AM -0400, Yan Zhao wrote:
> On Tue, Jul 16, 2019 at 03:23:16PM +0800, Peter Xu wrote:
> > On Tue, Jul 16, 2019 at 03:10:42PM +0800, Yan Zhao wrote:
> > > for some devices to do live migration, it is needed to do something
> > > immediately before vcpu stops. add a notification here.
> > 
> > Hi, Yan,
> > 
> > Could I ask for a more detailed commit message here?  E.g., what is
> > "some devices"?  And, what's the problem behind?
> >
> hi Peter,
> 
> Some devices refer to assigned devices, like NICs.
> For assigned devices to do live migration, it is sometimes required that
> source device is stopped before stopping source vcpus. vcpus can do some
> final cleanups (like handling interrupt) in that case.

I see, so this is a prerequisite of another work?

IMHO it would make more sense to have this patch to be with that
patchset, then it'll justify itself with reasoning.  Unless I
misunderstood - this single patch seems to help nothing if as a
standalone one.

Thanks,

-- 
Peter Xu