Re: [Qemu-devel] [PATCH v2] Add remove_boot_device_path() function for hot-unplug device

[Marcel Apfelbaum]

On Mon, 2014-04-28 at 14:48 +0200, Paolo Bonzini wrote:
> Il 28/04/2014 14:43, Marcel Apfelbaum ha scritto:
> >> > Yeah, but dangling pointers are bad anyway.  I think we should include
> >> > Jun's patch.
> > I have nothing against it, but maybe you/someone answer this question
> > which I honestly don't have the answer for:
> > After this patch you can replace a boot-able disk at index x.
> > What happens if you do so and the user reboots and selects index x?
> > Until now, the index was 'in use', even if the disk was hot-unplugged.
> > What are the consequences now? If we can live with them, I am all for using 
> > this patch.
> 
> Firmware does not use indices, it uses paths.  If boards do not update 
> the paths on reset, firmware behavior will be unmodified before/after 
> this patch.
> 
> With or without this patch, firmware will look for a device at the 
> address where the "first" index x was.  If there is no device there, 
> either firmware will crash or it will ignore the entry.  If there is a 
> device, it will boot from that device no matter what the bootindex was 
> on QEMU's command line.

Thanks for the explanation!
As I previously said, I agree with the patch.

Thanks,
Marcel 

> 
> Paolo