Re: [RFC PATCH] KVM: arm/arm64: GICv4: Support shared VLPI

From: Marc Zyngier
Date: Mon Nov 06 2023 - 10:33:21 EST


On Mon, 06 Nov 2023 14:59:01 +0000,
Kunkun Jiang <jiangkunkun@xxxxxxxxxx> wrote:
>
> The virtio-pci driver write entry1-6
> massage.data in the msix-table and trap to QEMU for processing. The
> massage.data is as follow:
> > entry-0 0
> > entry-1 1
> > entry-2 1
> > entry-3 1
> > entry-4 1
> > entry-5 1
> > entry-6 1

Urgh... is vp_modern_queue_vector() used in your configuration? This
is ... terrible.

I wonder if PCIe actually allows this sort of thing.

In any case, this sort of behaviour breaks so many thing in KVM's
implementation that I'd recommend you disable GICv4 until we have a
good solution for that.

M.

--
Without deviation from the norm, progress is not possible.