Re: [PATCH v3 01/10] KVM: arm64: vgic: Store LPIs in an xarray

From: Oliver Upton
Date: Tue Feb 20 2024 - 12:57:52 EST


On Tue, Feb 20, 2024 at 05:53:55PM +0000, Marc Zyngier wrote:
> On Tue, 20 Feb 2024 17:43:03 +0000, Oliver Upton <oliver.upton@xxxxxxxxx> wrote:
> > I think we can get into here both from contexts w/ interrupts disabled
> > or enabled. irqfd_wakeup() expects to be called w/ interrupts disabled.
> >
> > All the more reason to use irqsave() / irqrestore() flavors of all of
> > this, and a reminder to go check all callsites that implicitly take the
> > xa_lock.
>
> Sounds good. Maybe you can also update the locking order
> "documentation" to include the xa_lock? I expect that it will
> ultimately replace lpi_list_lock.

Yep, I got to the point of deleting the lpi_list_lock on the full
series, which is where I update the documentation. I really didn't want
people to know I'm adding yet another layer of locking in the interim...

Anyways, I think there's sufficient feedback to justify a respin. I'll
make sure the documentation is updated w/ the xa_lock for the stuff I'm
trying to land in 6.9.

--
Thanks,
Oliver