Re: [Xen-devel] [PATCH] xen/x86: Use 2M superpages for text/data/bss mappings

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 22.02.16 at 11:24, <andrew.cooper3@xxxxxxxxxx> wrote:
> On 22/02/16 09:55, Jan Beulich wrote:
>>>>> --- a/xen/arch/x86/xen.lds.S
>>>>> +++ b/xen/arch/x86/xen.lds.S
>>>>> @@ -38,6 +38,9 @@ SECTIONS
>>>>>    . = __XEN_VIRT_START;
>>>>>    __image_base__ = .;
>>>>>  #endif
>>>>> +
>>>>> +  __2M_text_start = .;         /* Start of 2M superpages, mapped RX. */
>>>> Is the reason for aforementioned build problem perhaps the fact
>>>> that this label (and the others too) lives outside of any section?
>>> I am not sure.  It is only this symbol which is a problem.  All others
>>> are fine.
>>>
>>> I actually intended this to be an RFC patch, to see if anyone had
>>> suggestions.
>> Since you now imply this to be at the image base, I don't see
>> why using e.g. __XEN_VIRT_START (in its place, or via #define)
>> wouldn't be as good an option.
> 
> I don't understand what you mean here.
> 
> If you are suggesting #define __2M_text_start __XEN_VIRT_START then I
> don't see how that is going to help with the relocation.

Why not? __XEN_VIRT_START is a constant, i.e. won't result in
any relocations to get emitted.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel