Re: [PATCHv4 15/30] x86/boot: Allow to hook up alternative port I/O helpers

From: Dave Hansen
Date: Thu Feb 24 2022 - 17:14:13 EST


On 2/24/22 07:56, Kirill A. Shutemov wrote:
> Port I/O instructions trigger #VE in the TDX environment. In response to
> the exception, kernel emulates these instructions using hypercalls.
>
> But during early boot, on the decompression stage, it is cumbersome to
> deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE
> handling.
>
> Add a way to hook up alternative port I/O helpers in the boot stub.

I'd add one more sentence to that:

... with a new pio_ops structure. For now, set the ops structure to
just call the normal I/O operation functions.

But, either way:

Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>