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RE: [Xen-ia64-devel] paravirt_ops and its alternatives

To: "Kouya Shimura" <kouya@xxxxxxxxxxxxxx>
Subject: RE: [Xen-ia64-devel] paravirt_ops and its alternatives
From: "Dong, Eddie" <eddie.dong@xxxxxxxxx>
Date: Tue, 5 Feb 2008 21:47:13 +0800
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Thread-topic: [Xen-ia64-devel] paravirt_ops and its alternatives
Kouya Shimura wrote:
> Dong, Eddie writes:
>>      3: irq chip paravirt_ops, xen irq chip or vSAPIC?
> Is xen irqchip really necessary?

X86 side already pushed the xen irq chip into upstream, so I think
it should be easy to do same thing in IPF side.

> In current PV implementation, an evtchn interrupt is injected and
> reflected directly to a guest OS. 
> See reflect_event()@xen-unstable.hg/xen/arch/ia64/xen/faults.c and
> xen_event_callback@xxxxxxxxxxxxxxxxxxx/arch/ia64/xen/xenivt.c 

Yes, this is xen irq chip. It should have better performance than
We need to re-do this base on upstream xen riq chip code, + debug, it is
more than vSAPIC, but love to see going in this direction since x86
pushed it.

> There is no intermediate layer there.
> I think that the same mechanism can work in paravirt_ops.
> Perhaps I might misunderstand something. :-)

Just term difference :) basically we are talking about same thing.

thx, eddie

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