[PATCH] um: add back support for FXSAVE registers

[SeongJae Park]

Hello,

On Wed, 4 Dec 2024 08:48:27 +0100 Benjamin Berg <benjamin at sipsolutions.net> wrote:

> From: Benjamin Berg <benjamin.berg at intel.com>
> 
> It was reported that qemu may not enable the XSTATE CPU extension, which
> is a requirement after commit 3f17fed21491 ("um: switch to regset API
> and depend on XSTATE"). Add a fallback to use FXSAVE (FP registers on
> x86_64 and XFP on i386) which is just a shorter version of the same
> data. The only difference is that the XSTATE magic should not be set in
> the signal frame.
> 
> Note that this still drops support for the older i386 FP register layout
> as supporting this would require more backward compatibility to build a
> correct signal frame.
> 
> Fixes: 3f17fed21491 ("um: switch to regset API and depend on XSTATE")
> Reported-by: SeongJae Park <sj at kernel.org>
> Closes: https://lore.kernel.org/r/20241203070218.240797-1-sj@kernel.org
> Tested-by: SeongJae Park <sj at kernel.org>
> Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>

Seems this patch is not yet merged into uml/next or uml/fixes.  May I ask the
timeline or blockers for this patch?


Thanks,
SJ

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