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References: <20181219085038.7729-1-peterx@redhat.com>
	<20181219085038.7729-3-peterx@redhat.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <c9e56e11-214f-552a-faea-cb5901392164@redhat.com>
Date: Wed, 19 Dec 2018 21:12:55 +0100
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Subject: Re: [Qemu-devel] [PATCH 2/4] q35: set split kernel irqchip as
 default
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To: Peter Xu <peterx@redhat.com>, qemu-devel@nongnu.org
Cc: "Michael S . Tsirkin" <mst@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>, Igor Mammedov <imammedo@redhat.com>

On 19/12/18 09:50, Peter Xu wrote:
> Starting from QEMU 4.0, let's specify "split" as the default value for
> kernel-irqchip.
> 
> So for QEMU>=4.0 we'll have: allowed=Y,required=N,split=Y
>    for QEMU<=3.1 we'll have: allowed=Y,required=N,split=N
>    (omitting all the "kernel_irqchip_" prefix)
> 
> Note that this "split" is optional - we'll first try to enable split
> kernel irqchip, and we'll fall back to complete kernel irqchip if we
> found that the kernel capability is missing.

Please just fail completely and require a new kernel for the 4.0 machine
type.  There are subtle differences between kernel and QEMU irqchip, I
don't think we want to open that can of worms.

Paolo