[Qemu-devel] Re: [PATCH 0/3]: Add UUID command-line option

[Anthony Liguori <anthony@codemonkey.ws>]

Gleb Natapov wrote:
>
> CMOS has enough memory for UUID, but UUID is not the only thing that
> needs to be passed to BIOS, so eventually we can run out of space there.
>   

I'm inclined to think that on a real machine, the UUID is stored in the 
CMOS.

> For example we have a requirement to pass additional ACPI tables that
> user may specify on command line.

What's the use-case?  I don't think this is a very good idea.

>  There is no enough space to put those
> tables into CMOS. What I did is that: BIOS passes to qemu address where to
> store additional tables (via backdoor) and qemu copies them there. To
> this scheme to work there should be bidirectional channel between qemu
> and BIOS. Other then that I am not particularly attached to vmware
> backdoor :)
>   

You can not arbitrarily extend the backdoor interface.  It's an 
interface defined and controlled by VMware.  If you extend it, you risk 
breaking other OSes that are assuming that interface has a different 
meaning.

Regards,

Anthony Liguori
> --
> 			Gleb.
>