Re: [PATCH 2/3] x86/boot: Reuse code to relocate trampoline

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 07/10/2024 10:04 am, Jan Beulich wrote:
> On 07.10.2024 10:15, Frediano Ziglio wrote:
>> On Mon, Oct 7, 2024 at 9:07 AM Frediano Ziglio
>> <frediano.ziglio@xxxxxxxxx> wrote:
>>> On Mon, Oct 7, 2024 at 8:03 AM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>>>> On 05.10.2024 15:21, Andrew Cooper wrote:
>>>>> On 05/10/2024 9:02 am, Frediano Ziglio wrote:
>>>>>> --- a/xen/arch/x86/boot/Makefile
>>>>>> +++ b/xen/arch/x86/boot/Makefile
>>>>>> @@ -1,6 +1,6 @@
>>>>>> -obj-bin-y += head.o cbundle.o
>>>>>> +obj-bin-y += head.o cbundle.o reloc-trampoline.x64.o
>>>>> Ah.  I think the $(obj)/%.x64.o rule you had in the previous patch wants
>>>>> introducing here.
>>>>>
>>>>> That said, x64 is the one name for 64bit that we reliably don't use.
>>>>> Also...
>>>>>
>>>>>> -head-bin-objs := cmdline.o reloc.o
>>>>>> +head-bin-objs := cmdline.o reloc.o reloc-trampoline.o
>>>>> ... head-bin-objs isn't really correct now seeing as they're not
>>>>> binaries in head.S.  Also ...
>>>>>
>>>>>>  nocov-y   += $(head-bin-objs)
>>>>>>  noubsan-y += $(head-bin-objs)
>>>>> The no$(foo)'s needs extending to the 64bit objects too.  They're also
>>>>> used early enough to explode.
>>>>>
>>>>> In Xen, 64bit objects are the norm, and it's 32bit ones which are the
>>>>> exception, so how about we special case *.i386.o instead.  Then
>>>>>
>>>>> obj32 := cmdline.i386.o
>>>>> obj32 += reloc.i386.o
>>>>> obj32 += reloc-trampoline.i386.o
>>>> I'd like to advocate for ix86 or i686. i386 gives a wrong impression imo.
>>> Why not simply x86 ? We already use it.
>>>
>> Looking at current files, we also use (to distinguish more clearly 32
>> and 64 bit) x86_32.
> Either would be fine with me; as to x86 I took it that Andrew wanted to
> express the 32-bit-ness, which x86 alone doesn't unambiguously do.

On further thought, why not just foo.32.o ?

That should be clear enough.

~Andrew