[PATCH v3 11/11] KVM: arm64: Drop sve_cond_update_zcr_vq_*

[Oliver Upton]

Hi,

On Tue, May 28, 2024 at 01:59:14PM +0100, Fuad Tabba wrote:
> The conditional update likely doesn't help performance, but makes
> the code a bit more difficult to read. Remove these macros and
> just write directly to ZCR.
> 
> Signed-off-by: Fuad Tabba <tabba at google.com>
> ---
> This patch is meant as an RFC, and undoes the previous patch.
> Please feel free to accept/drop whichever patches you think make
> sense.

The motivation behind this helper is to avoid unnecessary synchronizing
behavior, since as you note the architecture does not require
explicit synchronization for the value to become visible to subsequent
instructions.

Now, that doesn't _necessarily_ imply full blown context synchronization,
but it isn't too far fetched to think a conservative implementation does
exactly that upon ZCR write.

-- 
Thanks,
Oliver