linux-kernel - Re: [PATCH 1/2] KVM: X86: remove read buffer for mmio read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120710130149.GE23898@redhat.com>
Date:	Tue, 10 Jul 2012 16:01:50 +0300
From:	Gleb Natapov <gleb@...hat.com>
To:	Avi Kivity <avi@...hat.com>
Cc:	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: Re: [PATCH 1/2] KVM: X86: remove read buffer for mmio read

On Tue, Jul 10, 2012 at 03:50:39PM +0300, Avi Kivity wrote:
> 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.
> 
The cache is flashed only before instruction decode, never during
emulation.

--
			Gleb.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/