Re: [Qemu-devel] [RFC PATCH 0/5] modify boot order when vm is running

[Gonglei (Arei)]

> -----Original Message-----
> From: Michael S. Tsirkin [mailto:address@hidden
> Sent: Monday, July 07, 2014 5:29 PM
> To: Gonglei (Arei)
> Cc: address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
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> Huangweidong (C); Luonengjun; Huangpeng (Peter); chenliang (T)
> Subject: Re: [RFC PATCH 0/5] modify boot order when vm is running
> 
> On Mon, Jul 07, 2014 at 05:10:56PM +0800, address@hidden wrote:
> > From: Chenliang <address@hidden>
> >
> > Sometime, we want to modify boot order of vm without shutdown it.
> > This sets of patches add one qmp to achieve it. And fix some little
> > bug when device is hotpluged.
> >
> > Chenliang (5):
> >   bootindex: add *_boot_device_path function
> >   bootindex: reset bootindex when vm reset
> >   bootindex: delete boot index when device is removed
> >   bootindex: add qmp to set boot index when vm is running
> >   bootindex: fix memory leak when ppc sets boot index
> 
> Unfortunately at least for PC, boot order is exposed
> in fw cfg which can not change while guest is running.

Yes, so we should assure it take effect after the guest rebooting. 

> I suspect we need to change how we report boot order to guests.
> While we are at it, maybe we can fix the silly bootindex
> convention: I think people really want to specify boot *order*,
> not boot index.
> 
Agreed.

But at present, the boot index can be used for the boot order 
except "-boot" command line. Because "-boot" only can assign
the guest booting from HD or Network or Floppy etc.. but cannot
assign the index of hard disks or PXE net cards, which not be enough
for many scenes, such as P2V, or two different system hard disks
(vda/sda/hda).


Best regards,
-Gonglei