Re: Fix for xen guest with mem > 3.7G

[Jeremy Fitzhardinge <jeremy@goop.org>]

Roberto De Ioris wrote:
> Xen domU kernel 2.6.26 and 2.6.27-rc cannot allocate
> more than 3.7GB of ram on my PAE systems (compiled
> with gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu7)).
>
> I have found the problem is in function xen_memory_setup (in
> arch/x86/xen/setup.c).
>
> It set max_pfn as 'unsigned long' but add_memory_region()
> takes 'unsigned long long'.
>
> I do not know if it is a compiler problem but this is the simple fix
> (works on my systems):
>   

Thanks very much for the patch.  We have a more general fix for this in
Ingo's tip.git tree, but I overlooked that this particular problem
affected current -rc.

Ingo, this is fixed by the phys_addr_t + PFN_PHYS() patches.  Should we
send them up to Linus, or do an ad-hoc fix in this one place?

Thanks,
    J

> --- setup.c.orig	2008-09-13 21:12:56.000000000 +0200
> +++ setup.c	2008-09-13 20:35:29.000000000 +0200
> @@ -36,7 +36,7 @@
>  
>  char * __init xen_memory_setup(void)
>  {
> -	unsigned long max_pfn = xen_start_info->nr_pages;
> +	unsigned long long max_pfn = xen_start_info->nr_pages;
>  
>  	e820.nr_map = 0;
>  	add_memory_region(0, LOWMEMSIZE(), E820_RAM);
>
>
>
>