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From: Markus Armbruster <armbru@redhat.com>
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Date: Wed, 17 Jun 2015 09:11:56 +0200
In-Reply-To: <20150617085742-mutt-send-email-mst@redhat.com> (Michael
	S. Tsirkin's message of "Wed, 17 Jun 2015 08:58:35 +0200")
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Subject: Re: [Qemu-devel] [PATCH] Migration compatibility for serial
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: amit.shah@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org, "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>, quintela@redhat.com

"Michael S. Tsirkin" <mst@redhat.com> writes:

> On Wed, Jun 17, 2015 at 08:52:42AM +0200, Markus Armbruster wrote:
>> "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> writes:
>> 
>> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> >
>> > Older QEMUs dont understand the new (sub)sections that
>> > may be generated in the serial device.   Limit their generation
>> > to newer machine types.
>> 
>> Please explain briefly what state migration can lose with old machine
>> types, and how this could impact the guest.  The commits adding the
>> subsections should have the information[*].  Pointers to them might
>> suffice.
>> 
>> 
>> [*] Should != do; I didn't check.
>
> OTOH if we have flags named after specific portions we skip,
> and not after qemu versions, this becomes evident from code.

The commit message needs to spell things out regardless.