Re: [Qemu-devel] [PATCH REPOST 2/2] dump-guest-memory: add basic "detach" support.

["Daniel P. Berrange" <berrange@redhat.com>]

On Mon, Nov 23, 2015 at 06:07:42PM +0800, Peter Xu wrote:
> This will allow the user specify "-d" (just like command
> "migrate") when using "dump-guest-memory" command. When
> specified, one background thread is created to do the dump work.
> One flag is added to show whether there is a background dump
> work in progress.

Your comparison to the 'migrate' command is not entirely
accurate. While the 'detach' flag exist in the QMP parameters
schema, it is invalid to use it - migration is always backgrounded
in QMP.

[quote src="qmp-commands.hx"]
  (3) The user Monitor's "detach" argument is invalid in QMP and should not
    be used
[/quote]

A further difference is that with migrate, you can use
'info migrate' to determine if the operation is complete.
AFAIK, with this proposal there's no way to see if the
dump is complete - you just have to keep runing 'cont'
until it doesn't return an error.

I'm curious about the intended usage of this change
and whether this design satisfies the requirements
it may have

Regards,
Daniel
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