RE: [PATCH 6/6] x86/gsseg: use the LKGS instruction if available for load_gs_index()

[Li, Xin3]

> Something like so perhaps?
> 
> 	asm_inline volatile("1:\n"
> 			    ALTERNATIVE("call asm_load_gs_index\n",
> 					LKGS_DI,
> 					X86_FEATURE_LKGS)
> 			    _ASM_EXTABLE_TYPE_REG(1b, 1b,
> EX_TYPE_ZERO_REG, %k[sel])
> 			    : ASM_CALL_CONSTRAINT
> 			    : [sel] "D" (sel)
> 			    : "memory", _ASM_AX);
> 
> 
> (completely untested, not even seen a compiler upclose)

It compiles (after adding "0x3e" to make it 5 bytes to match the size of "call asm_load_gs_index") and passes my fixup test, thanks!