Re: [Qemu-devel] [PATCH v8 00/30] modify boot order of guest, and take effect after rebooting

[Gonglei (Arei)]

> > 主题: RE: [Qemu-devel] [PATCH v8 00/30] modify boot order of guest, and
> take
> > effect after rebooting
> >
> > > > 主题: [Qemu-devel] [PATCH v8 00/30] modify boot order of guest, and
> > > > take effect after rebooting
> > > >
> > > > From: Gonglei <address@hidden>
> > > >
> > > > Sometimes, we want to modify boot order of a guest, but no need to
> > > shutdown
> > > > it. We can call dynamic changing bootindex of a guest, which can be
> > > > assured taking effect just after the guest rebooting.
> > >
> > > What about interactive boot menu?
> > >
> > If you are using libvirt API, you can using libvirt interface to do 
> > this(I'm not
> sure
> > whether have ready-to-wear qom-set interface or not).
> > If you are using qemu command line boot vm, you can by qom-set directly.
> > See my test case please.
> >
> > > >
> > > > For example, in P2V scene, we boot a guest and then attach a new
> > > > system
> > > disk,
> > > > for copying some thing. We want to assign the new disk as the
> > > > booting disk, which means its bootindex=1.
> > >
> > > you're aiming hotplug cases?
> >
> > Including, but not limited to hotplugging situation. All devices which 
> > support
> > boot, regardless hotplug or coldplug in command line.
> >
> > > So, do you have to QOMize bootindex of other devices?
> > >
> > By the previous conversation, using QOM is the best way for bootindex
> > property.
> > In this way, we needn't to introduce a new qmp interface.
> > Of course, we should realize all devices.
> 
> I mean,
> If you reset machine, interactive boot-menu can pop-up for you to

Optional. Only when you configure ' -boot menu=on' in command line, we
can choose boot menu by pressing F12. And there is some other limit, such
as supporting max ten items (0~9) we can choose...

> select boot-order, and if boot-menu doesn't service your purpose(e.g. hotplug
> devices),
> you can make change to set boot-order correctly, that's the way real machine
> works, right?

Using 'boot -menu' is just a scenario of changing device boot order. If someone
Haven't configure vnc-server or other ui, they will not can change boot order,
which is different with the real world.
 
> Yes, somebody may want to change boot-order by qmp or hmp, we should just
> emulate
> what we do for boot-menu, qomize bootindex for all devices(boot possible)
> seemed a little bit over-engineering for me.
> 
See above pls. I don't agree with you.

Best regards,
-Gonglei