Re: [PATCH v2 5/6] x86/hvm: limit memory type cache flush to running domains

[Jan Beulich <jbeulich@xxxxxxxx>]

On 16.05.2025 11:45, Roger Pau Monne wrote:
> Avoid the cache flush if the domain is not yet running.  There shouldn't be
> any cached data resulting from domain accesses that need flushing, as the
> domain hasn't run yet.

This again plays into what we started discussing already: There may still be
data in caches due to Xen or toolsstack behavior. Imo to compensate we'd need
to do one flush right before unleashing the domain. Yet of course this makes
sense only when we make sure to not have (cachable) mapping in Xen for any of
the affected ranges. Hence, with that not presently being the case, ...

> No change in domain observable behavior intended.

... I agree here, thus ...

> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

The situation may want discussing a bit more in the description, though,
which would make me feel less uneasy about that R-b.

Jan