[PATCH 2/4] irqchip/gic-v3-its: Implement .msi_teardown() callback

[Thomas Gleixner]

On Mon, May 12 2025 at 17:09, Marc Zyngier wrote:
> On Mon, 12 May 2025 15:34:59 +0100,
> Thomas Gleixner <tglx at linutronix.de> wrote:
>
> Changing prepare first breaks nvme and igbxe, amongst other things,
> for the reasons explained just above, so you need to implement
> teardown first, plug the MSI controller into it, and only then you can
> switch prepare.
>
> What I can do is:
>
> (1) introduce teardown without the call site in msi_remove_device_irq_domain()
>
> (2) add its implementation in the ITS driver
>
> (3) move the prepare crap
>
> (4) add the teardown call to msi_remove_device_irq_domain(), without
>     the check on info->alloc_data
>
> With that order, everything will keep working, with a temporary leak
> of ITTs in the ITS driver between patches (2) and (4).
>
> Is that something you can live with?

Sounds good.