Message-ID: <4DF5C50D.2000007@redhat.com>
Date: Mon, 13 Jun 2011 11:06:37 +0300
From: Avi Kivity <avi@redhat.com>
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To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
CC: Marcelo Tosatti <mtosatti@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
        KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 0/15] KVM: optimize for MMIO handled
References: <4DEE205E.8000601@cn.fujitsu.com> <4DF0789B.2050401@redhat.com> <4DF19803.9040407@cn.fujitsu.com> <4DF47D0A.9060604@redhat.com> <4DF5961A.6050006@cn.fujitsu.com>
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On 06/13/2011 07:46 AM, Xiao Guangrong wrote:
> >>
> >>  and it has little heavy sine we need to walk guest page table,
> >>  and build spte under mmu-lock.
> >
> >  For shadow, yes, this is a good optimization.  But with nested paging it slow things down.  We already have the gpa, so all we need to do is follow the mmio path.  There's no need to walk the spte hierarchy.
> >
>
> Yes, it is, i just want to detect BUG for KVM, it helps us to know if "ept misconfig" is the
> real MMIO or the BUG. I noticed some "ept misconfig" BUGs is reported before, so i think doing
> this is necessary, and i think it is not too bad, since walking spte hierarchy is lockless,
> it really fast.

Okay.  We can later see if it show up on profiles.


-- 
error compiling committee.c: too many arguments to function

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