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To: Andre Przywara <andre.przywara@arm.com>
Subject: Re: [PATCH v2] kvm: arm: VGIC: Fix interrupt group enablement
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Date: Mon, 25 Nov 2019 10:55:01 +0000
From: Marc Zyngier <maz@kernel.org>
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On 2019-11-22 18:51, Andre Przywara wrote:
> Hi Marc,
>
> this is still a bit rough, and only briefly tested, but I wanted to
> hear your opinion on the general approach (using a second list in
> addition to the ap_list). Some ugly bits come from the fact that the
> two lists are not that different, so we have to consider both of them
> at times. This is what I wanted to avoid with just one list that gets
> filtered on the fly.
> Or I am just stupid and don't see how it can be done properly ;-)

I don't know about that, but I think there is a better way.

You have essentially two sets of pending interrupts:

1) those that are enabled and group-enabled, that end up in the AP list
2) those that are either disabled and/or group-disabled

Today, (2) are not on any list. What I'm suggesting is that we create
a list for these interrupts that cannot be forwarded.

Then enabling an interrupt or a group is a matter of moving pending
interrupts from one list to another. And I think most of the logic
can be hidden in vgic_queue_irq_unlock().

         M.
-- 
Jazz is not dead. It just smells funny...
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