Re: [PATCH for-4.22 v2.5] xen/arm: gic: defer host LPI allocation until after ITS init

[Julien Grall <julien@xxxxxxx>]

On 19/06/2026 12:34, Orzel, Michal wrote:
> On 19-Jun-26 13:23, Julien Grall wrote:
> > Hi Michal,
> >
> > On 19/06/2026 10:48, Orzel, Michal wrote:
> > > @Oleksii, can we ask for a release ack here?
> > Can you explain the pros/cons of introducing this patch quite late?
> The advantage is that it fixes the broken LPIs on affected hardware.
> The disadvantage is the reordering risk but I don't think there is 
any issue.
See more below.
> > One of the risk here is that we are now initializing the LPIs *after*
> > the ITSes. I understand this is because we want to know the workaround.
> > However, I vaguely recall that there was a dependency in the
> > configuration. So are we confident the new ordering will not bring other
> > issues? Ideally this should have been explained in the commit message.
> gic-v3-its.c never references host LPI state, so ITS init has no dependency on 
> LPIs.
My concern is at the HW level. The ITS is using LPIs. But we will 
configure the ITS first and then the LPIs.
What probaly saves us is the fact gicv3_lpi_init_host_lpis() only seem 
to allocate memory. This is a bit fragile though.
Cheers,

--
Julien Grall