Re: [patch V5 02/38] x86/entry/64: Use native swapgs in asm_native_load_gs_index()

From: Thomas Gleixner
Date: Wed May 13 2020 - 02:35:31 EST


Steven Rostedt <rostedt@xxxxxxxxxxx> writes:
> On Tue, 12 May 2020 23:01:01 +0200
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
>> When PARAVIRT_XXL is in use, then load_gs_index() uses
>> xen_load_gs_index() and (asm_))native_load_gs_index() is unused.
>>
>> It's therefore pointless to use the paravirtualized SWAPGS implementation
>> in asm_native_load_gs_index(). Switch it to a plain swapgs.
>>
>> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Cc: Juergen Gross <jgross@xxxxxxxx>
>> ---
>> arch/x86/entry/entry_64.S | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> --- a/arch/x86/entry/entry_64.S
>> +++ b/arch/x86/entry/entry_64.S
>> @@ -1043,11 +1043,11 @@ idtentry simd_coprocessor_error do_simd
>> */
>> SYM_FUNC_START(asm_native_load_gs_index)
>
> Small nit, but I would just call this: asm_load_gs_index.
>
> The "native" word is usually reserved for functions that are for bare
> metal and have a paravirt counterpart. As there is a
> native_load_gs_index(), I don't envision a need for a paravirt version
> of the asm function.

Fair enough.