Re: [PATCH 1/2] x86/video: add boot_video_info offset generation to asm-offsets

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Apr 02, 2024 at 11:43:49AM +0200, Jan Beulich wrote:
> On 02.04.2024 11:38, Jan Beulich wrote:
> > On 28.03.2024 16:35, Roger Pau Monne wrote:
> >> Currently the offsets into the boot_video_info struct are manually encoded 
> >> in
> >> video.S, which is fragile.  Generate them in asm-offsets.c and switch the
> >> current code to use those instead.
> > 
> > Just to mention it (without asking for immediate action): Defining 
> > boot_vid_info
> > in assembly code then is as fragile. Moving to C would likely be problematic
> > because it needs to be in the trampoline range. But at least its size 
> > should (at
> > some point) perhaps better be tied to the C struct's sizeof().
> 
> Actually I overlooked that you partly do this. The use of BVI_capabilities 
> there
> looks odd to me, though. Why not
> 
>         .space  BVI_size - (. - boot_vid_info)
> 
> ? I realize it becomes just BVI_size in patch 2, but I have some question 
> there,
> too.

I didn't think much about this because it was going away in the next
patch, but let me adjust.  In fact I was tempted to just use BVI_size
and allocate more than required.

Thanks, Roger.