From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: Re: APIC rework
Date: Tue, 17 Nov 2009 05:44:15 +0000
Message-ID: <C727E8AF.C051%keir.fraser@eu.citrix.com>
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To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Xen-devel <xen-devel@lists.xensource.com>, "Han,
	Weidong" <weidong.han@intel.com>, "Zhang,
	Xiantao" <xiantao.zhang@intel.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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On 17/11/2009 05:20, "Jeremy Fitzhardinge" <jeremy@goop.org> wrote:

> On 11/16/09 19:45, Keir Fraser wrote:
>> It's kind of a shame to need this though. Is there no way for the hypervisor
>> to work out automatically whether an older dom0 is running? Or work out the
>> trigger/level stuff for itself (after all it parses the relevant bios tables
>> just like dom0)?
> 
> If Xen can set the interrupt triggering by itself, why would it ever
> need dom0 to do it?  Couldn't it just preconfigure all the pins, and
> then wait for dom0 to provide/request the pirq<->evtchn mapping?

Very fair question. As long as Xen knows which GSI is being addressed (which
I'm sure it can work out), the rest should follow. I don't think even things
like PCI hotplug complicate this -- IOAPIC pins themselves are static.

 -- Keir