Re: [RFC PATCH 28/33] irqchip/gic-v3-its: Support VPE doorbell invalidation even when !DirectLPI
From: Thomas Gleixner
Date: Mon Feb 13 2017 - 06:16:11 EST
On Tue, 17 Jan 2017, Marc Zyngier wrote:
> When we don't have the DirectLPI feature, we must work around the
> architecture shortcomings to be able to perform the required
> invalidation.
>
> For this, we create a fake device whose sole purpose is to
> provide a way to issue a map/inv/unmap sequence (and the corresponding
> sync operations). That's 6 commands and a full serialization point
> to be able to do this.
>
> You just have hope the hypervisor won't do that too often...
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>