From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 1/2] KVM: X86: remove read buffer for mmio read
Date: Tue, 10 Jul 2012 15:50:39 +0300
Message-ID: <4FFC251F.4050504@redhat.com>
References: <4FFA9E16.10001@linux.vnet.ibm.com> <4FFABD59.2070108@redhat.com> <20120709112346.GA23898@redhat.com> <4FFAD341.3080508@redhat.com> <4FFADB37.4090705@linux.vnet.ibm.com> <4FFADDFA.5000603@redhat.com> <20120710103629.GC23898@redhat.com> <4FFC07BB.8080802@redhat.com> <20120710104847.GD23898@redhat.com>
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Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
To: Gleb Natapov <gleb@redhat.com>
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In-Reply-To: <20120710104847.GD23898@redhat.com>
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On 07/10/2012 01:48 PM, Gleb Natapov wrote:
> > > > 
> > > But the code is already here, why drop it?
> > 
> > The read cache is not effective for multiple disjunct reads.
> What do you mean?

If an instruction reads from several sources in mmio, then the first
read will be flushed from the cache by the second read.  So if we need a
third read, we'll have to exit for the first again.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.