[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 3/4] doc: add item for "-M enforce-config-sectio
From: |
Peter Xu |
Subject: |
Re: [Qemu-devel] [PATCH 3/4] doc: add item for "-M enforce-config-section" |
Date: |
Thu, 6 Jul 2017 10:00:03 +0800 |
User-agent: |
Mutt/1.5.24 (2015-08-30) |
On Wed, Jul 05, 2017 at 05:31:22PM +0200, Markus Armbruster wrote:
> Eduardo Habkost <address@hidden> writes:
>
> > (CCing Greg, the original author of the code that added the
> > enforce-config-section option)
> >
> > On Tue, Jul 04, 2017 at 10:06:54AM +0200, Markus Armbruster wrote:
> >> Peter Xu <address@hidden> writes:
> >>
> >> > It's never documented, and now we have one more parameter for it (which
> >> > means this one can be obsolete in the future). Document it properly.
> >> >
> >> > Although now when enforce-config-section is set, it'll override the
> >> > other "-global" parameter, that is not necessarily a rule. Forbid that
> >> > usage in the document.
> >> >
> >> > Suggested-by: Eduardo Habkost <address@hidden>
> >> > Signed-off-by: Peter Xu <address@hidden>
> >> > ---
> >> > qemu-options.hx | 8 ++++++++
> >> > 1 file changed, 8 insertions(+)
> >> >
> >> > diff --git a/qemu-options.hx b/qemu-options.hx
> >> > index 297bd8a..927c51f 100644
> >> > --- a/qemu-options.hx
> >> > +++ b/qemu-options.hx
> >> > @@ -85,6 +85,14 @@ Enables or disables NVDIMM support. The default is
> >> > off.
> >> > @item s390-squash-mcss=on|off
> >> > Enables or disables squashing subchannels into the default css.
> >> > The default is off.
> >> > address@hidden enforce-config-section=on|off
> >> > +Decides whether we will send the configuration section when doing
> >> > +migration. By default, it is turned on. We can set this to off to
> >> > +explicitly disable it. Note: this parameter will be obsolete soon,
> >> > +please use "-global migration.send-configuration=on|off" instead.
> >>
> >> Please say "... is deprecated, please use ...", to make it visible in
> >> "git-grep -i deprecat".
> >>
> >> > +"enforce-config-section" cannot be used together with "-global
> >> > +migration.send-configuration". If it happens, the behavior is
> >> > +undefined.
> >>
> >> Nasty. Could we catch and reject such invalid usage?
> >
> > Actually, the machine option will override
> > migration.send-configuration=off, and I don't believe we will break that
> > rule. Documenting that behavior (but warning that it is deprecated)
> > sounds easier than adding extra code to detect the conflicting options.
> >
> > We can simply replace "is undefined" with "enforce-config-section will
> > override migration.send-configuration, but enforce-config-section is
> > deprecated".
>
> Better than the scary "behavior is undefined". But do we have to say
> anything at all? If somebody gives both options with different values,
> the conflicting settings fight it out. In a sane command line, the last
> one wins. Ours isn't sane. Do we really have to specify who wins?
>
> > I don't think anybody is relying on that option. If nobody is using it,
> > we can remove its code soon if we make it trigger a warning.
> > Machine-type compatibility code is already using
> > migration.send-configuration instead.
>
> What about
>
> @item enforce-config-section=on|off
> Controls sending of the configuration section when doing migration
> (default on).
Sorry to be misleading in current patch. Its default should be "off"
but not "on" (as corrected by Eduardo, the point is we are talking
about "enforce-config-section", not "migration.send-configuration").
Actually it won't make much sense if someone specify "off" here.
> Note: this parameter is deprecated, please use
> "-global migration.send-configuration=on|off" instead.
This is a suggestion I would like to take. I'll remove the whole
"undefined" sentence and update my post. Thanks,
--
Peter Xu
- Re: [Qemu-devel] [PATCH 2/4] vl: move global property, migrate init earlier, (continued)
[Qemu-devel] [PATCH 3/4] doc: add item for "-M enforce-config-section", Peter Xu, 2017/07/02
[Qemu-devel] [PATCH 4/4] doc: update TYPE_MIGRATION documents, Peter Xu, 2017/07/02
Re: [Qemu-devel] [PATCH 0/4] migration: fix iotest 055, only-migratable break, QingFeng Hao, 2017/07/03