From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yong Wang <yong.y.wang@linux.intel.com>
Subject: Re: [v3 13/26] KVM: Define a new interface kvm_find_dest_vcpu() for
 VT-d PI
Date: Mon, 22 Dec 2014 22:13:18 +0800
Message-ID: <20141222141318.GA12171@ywang-linux>
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Cc: "Wu, Feng" <feng.wu@intel.com>,
	"Zhang, Yang Z" <yang.z.zhang@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	"H. Peter Anvin" <hpa@linux.intel.com>,
	"x86@kernel.org" <x86@kernel.org>, Gleb Natapov <gleb@kernel.org>,
	"dwmw2@infradead.org" <dwmw2@infradead.org>,
	"joro@8bytes.org" <joro@8bytes.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Jiang Liu <public-jiang.liu-VuQAYsv1563Yd54FQh9/CA@plane.gmane.org>,
	"iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	KVM list <kvm@vger.kernel.org>,
	Eric Auger <eric.auger@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>
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On Mon, Dec 22, 2014 at 12:23:36PM +0100, Paolo Bonzini wrote:
> 
> 
> On 22/12/2014 12:17, Wu, Feng wrote:
> >> Yes, and those need not be accelerated.  But what if you set
> >> affinity to a single CPU?
> >
> > How do I set affinity to a single CPU if guest configure a lowest
> > priority interrupt? Thanks a lot!
> 
> I mean if the guest (via irqbalance and /proc/irq/) configures affinity
> to a single vCPU.  In that case, you can use PI.
> 

The problem is we still need to support PI with lowest priority delivery mode
even if guest does not configure irq affinity via /proc/irq/. Don't we?

Thanks
-Yong