From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.xen@gmail.com>
Subject: Re: [PATCH]: Allow tools to map arbitrarily large
 machphys_mfn_list on 32bit dom0
Date: Mon, 14 Mar 2011 15:08:57 +0000
Message-ID: <C9A3E009.14C17%keir.xen@gmail.com>
References: <1300115112.17229.78.camel@qabil.uk.xensource.com>
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To: Gianni Tedesco <gianni.tedesco@citrix.com>, Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: Tim Deegan <Tim.Deegan@eu.citrix.com>, Xen Devel <xen-devel@lists.xensource.com>, Jan Beulich <JBeulich@novell.com>
List-Id: xen-devel@lists.xenproject.org

Cc'ing Jan. I'd appreciate his Ack as this is his code originally. I don't
think we're missing anything subtle though.

 -- Keir

On 14/03/2011 15:05, "Gianni Tedesco" <gianni.tedesco@citrix.com> wrote:

> This permits suspend/resume to work with 32bit dom0/tools. AFAICT the
> limit to MACH2PHYS_COMPAT_NR_ENTRIES is redundant since that refers to a
> limit in kernel mappings under 32bit hypervisors, not userspace where
> there may be gigabytes of useful virtual space for this.
> 
> Suggested-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
> Signed-off-by: Gianni Tedesco <gianni.tedesco@citrix.com>
> 
> diff -r cf558cb8b92b xen/arch/x86/x86_64/compat/mm.c
> --- a/xen/arch/x86/x86_64/compat/mm.c Mon Mar 07 17:52:44 2011 +0000
> +++ b/xen/arch/x86/x86_64/compat/mm.c Mon Mar 14 14:58:04 2011 +0000
> @@ -162,8 +162,7 @@ int compat_arch_memory_op(int op, XEN_GU
>              return -EFAULT;
>  
>          limit = (unsigned long)(compat_machine_to_phys_mapping +
> -            min_t(unsigned long, max_page,
> -                  MACH2PHYS_COMPAT_NR_ENTRIES(current->domain)));
> +                    (unsigned long)max_page);
>          if ( limit > RDWR_COMPAT_MPT_VIRT_END )
>              limit = RDWR_COMPAT_MPT_VIRT_END;
>          for ( i = 0, v = RDWR_COMPAT_MPT_VIRT_START, last_mfn = 0;
> 
>