From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sheng Yang <sheng@linux.intel.com>
Subject: Re: [PATCH][v2] Hybrid extension support in Xen
Date: Tue, 2 Feb 2010 22:39:10 +0800
Message-ID: <201002022239.10384.sheng@linux.intel.com>
References: <C78DE7E9.8C2F%keir.fraser@eu.citrix.com>
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To: Keir Fraser <keir.fraser@eu.citrix.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Eddie Dong <eddie.dong@intel.com>, Jun Nakajima <jun.nakajima@intel.com>
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On Tuesday 02 February 2010 22:32:09 Keir Fraser wrote:
> On 02/02/2010 14:08, "Sheng Yang" <sheng@linux.intel.com> wrote:
> >> Okay, so that leads to the obvious next question: why do you want to
> >> avoid using INIT-SIPI-SIPI?
> >
> > Because we don't have IOAPIC/LAPIC...
> 
> Is it necessary to remove the LAPICs completely? If you go very far down
>  the route of ripping emulated stuff out of HVM, it starts to feel like
>  starting with a pure PV guest and HVMing it up is closer in spirit to what
>  you might be aiming for.

The performance of interrupt delivery is what we care about. The IOAPIC/LAPIC 
don't work well now, so we want event channel to eliminate their overhead, 
notably EOI in LAPIC.

And you know, start from a PV guest is another story...

-- 
regards
Yang, Sheng