[Lguest] [PATCH 23/25] [PATCH] paravirt hooks for arch initialization

[Glauber de Oliveira Costa]

Jeremy Fitzhardinge escreveu:
> Glauber de Oliveira Costa wrote:
>> I think the idea you gave me earlier of using probe_kernel_address could
>> work. Xen/lguest/put_yours_here that won't use an ebda would then have
>> to unmap the page, to make sure a read would fault.
> 
> Hm, the memory might be mapped anyway, but we could make sure its all
> zero.  discover_ebda should be able to deal with that OK.
> 
>     J
Indeed, as the EBDA_ADDR_POINTER is not aligned, this may work even better.

It seems to me safe to assume that if we read zero on that line:

ebda_addr = *(unsigned short *)__va(EBDA_ADDR_POINTER);

We could just do ebda_size = 0 and go home happy, skipping the rest of 
the process.

Andi, are you okay with it ?