From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH 3/3] KVM: MMU: mark page dirty only when page is really written Date: Mon, 02 Aug 2010 15:51:41 +0800 Message-ID: <4C56790D.60504@cn.fujitsu.com> References: <4C4E5313.1080308@cn.fujitsu.com> <4C4E536E.7030109@cn.fujitsu.com> <4C4E53F7.7050108@cn.fujitsu.com> <4C5678E3.8090309@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM list To: Avi Kivity Return-path: In-Reply-To: <4C5678E3.8090309@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > On 07/27/2010 06:35 AM, Xiao Guangrong wrote: >> Mark page dirty only when this page is really written, it's more exacter, >> and also can fix dirty page marking in speculation path >> >> Signed-off-by: Xiao Guangrong >> --- >> arch/x86/kvm/mmu.c | 47 >> ++++++++++++++++++++++++++++------------------- >> 1 files changed, 28 insertions(+), 19 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index dd6c192..bcc2173 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -311,24 +311,42 @@ static bool spte_bits_lost(u64 spte) >> if (!is_shadow_present_pte(spte)) >> return false; >> >> - if (spte& shadow_accessed_mask) >> + if (spte& shadow_accessed_mask&& >> + (!is_writable_pte(spte) || spte& shadow_dirty_mask)) >> return false; >> > > Please add parentheses around bitwise operators to reduce confusion. > The rest looks good. > OK, will do it in the new version, thanks.