From: Avi Kivity <avi@redhat.com>
To: "Hao, Xudong" <xudong.hao@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
Xudong Hao <xudong.hao@linux.intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Shan, Haitao" <haitao.shan@intel.com>,
"Zhang, Xiantao" <xiantao.zhang@intel.com>
Subject: Re: [PATCH 4/4] Enabling Access bit when doing memory swapping
Date: Mon, 21 May 2012 13:48:19 +0300 [thread overview]
Message-ID: <4FBA1D73.2030600@redhat.com> (raw)
In-Reply-To: <403610A45A2B5242BD291EDAE8B37D300FDC6E99@SHSMSX102.ccr.corp.intel.com>
On 05/21/2012 01:35 PM, Hao, Xudong wrote:
> >
> > That doesn't answer the question. An atomic operation is now non-atomic.
> >
> > You can calculate shadow_accessed_bit and keep on using clear_bit(), or
> > switch to cmpxchg64(), but don't just drop the dirty bit here.
> >
>
> I know your meaning. How about this changes:
>
> ...
> young = 1;
> + if (enable_ept_ad_bits)
> + clear_bit(ffs(shadow_accessed_mask), (unsigned long *)spte);
ffs() returns an off-by-one result, so this needs to be adjusted. IIRC
bsfl is slow, but this shouldn't be a problem here.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-05-21 10:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-16 1:12 [PATCH 4/4] Enabling Access bit when doing memory swapping Xudong Hao
2012-05-18 2:22 ` Marcelo Tosatti
2012-05-21 3:22 ` Hao, Xudong
2012-05-21 8:31 ` Avi Kivity
2012-05-21 10:35 ` Hao, Xudong
2012-05-21 10:48 ` Avi Kivity [this message]
2012-05-21 11:17 ` Hao, Xudong
2012-05-21 11:31 ` Avi Kivity
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