Re: [RFC PATCH v5 4/4] x86/acrn: Add hypercall for ACRN guest

From: Zhao, Yakui
Date: Sun Apr 28 2019 - 21:26:57 EST

On 2019å04æ28æ 18:03, Borislav Petkov wrote:
On Sun, Apr 28, 2019 at 09:56:35AM +0800, Zhao, Yakui wrote:
Thanks for the reminder about the access width.
It is 64-bit register. What I said is the "movq", not "movl".
(I understand that movl is incorrect for 64-bit register).

I didn't say anything about movl. I think what you're trying to say is
that because your inputs like hcall_id and param1/2 are unsigned longs,
you want a 64-bit move.

Yes. "movq" only indicates explicitly that it is 64-bit mov as ACRN guest only works under 64-bit mode.
I also check the usage of "mov" and "movq" in this scenario. There is no difference except that the movq is an explicit 64-op.
Of course "mov" is also ok to me that if you prefer the "mov".