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From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
	KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH v3 04/19] KVM: MMU: cache mmio info on page fault path
Date: Wed, 06 Jul 2011 09:17:21 +0800	[thread overview]
Message-ID: <4E13B7A1.9010504@cn.fujitsu.com> (raw)
In-Reply-To: <20110705190457.GA24417@amt.cnet>

On 07/06/2011 03:04 AM, Marcelo Tosatti wrote:
		return 0;
>>  
>>  	/* mmio */
>> -	if (is_error_pfn(pfn))
>> -		return kvm_handle_bad_page(vcpu->kvm, walker.gfn, pfn);
>> +	if (is_error_pfn(pfn)) {
>> +		unsigned access = walker.pte_access;
>> +		bool dirty = is_dirty_gpte(walker.ptes[walker.level - 1]);
>> +
>> +		if (dirty)
>> +			access &= ~ACC_WRITE_MASK;
>> +
>> +		return kvm_handle_bad_page(vcpu, mmu_is_nested(vcpu) ? 0 :
>> +					   addr, access, walker.gfn, pfn);
>> +	}
> 
> Don't get this... if guest pte is dirty you cache without allowing
> write access? Why?
> 

Ah, sorry, the logic should be: if pte is not diry, clear write access,
will fix it. Thanks, Marcelo!


  reply	other threads:[~2011-07-06  1:15 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-30  8:19 [PATCH v3 01/19] KVM: MMU: fix walking shadow page table Xiao Guangrong
2011-06-30  8:19 ` [PATCH v3 02/19] KVM: MMU: do not update slot bitmap if spte is nonpresent Xiao Guangrong
2011-06-30  8:20 ` [PATCH v3 03/19] KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code Xiao Guangrong
2011-06-30  8:20 ` [PATCH v3 04/19] KVM: MMU: cache mmio info on page fault path Xiao Guangrong
2011-07-05 19:04   ` Marcelo Tosatti
2011-07-06  1:17     ` Xiao Guangrong [this message]
2011-06-30  8:21 ` [PATCH v3 05/19] KVM: MMU: optimize to handle dirty bit Xiao Guangrong
2011-07-05 19:27   ` Marcelo Tosatti
2011-07-06  1:22     ` Xiao Guangrong
2011-07-06 16:51       ` Marcelo Tosatti
2011-07-06 19:12         ` Xiao Guangrong
2011-07-07  8:15           ` Marcelo Tosatti
2011-06-30  8:21 ` [PATCH v3 06/19] KVM: MMU: cleanup for FNAME(fetch) Xiao Guangrong
2011-06-30  8:22 ` [PATCH v3 07/19] KVM: MMU: rename 'pt_write' to 'emulate' Xiao Guangrong
2011-06-30  8:22 ` [PATCH v3 08/19] KVM: MMU: count used shadow pages on prepareing path Xiao Guangrong
2011-06-30  8:23 ` [PATCH v3 09/19] KVM: MMU: split kvm_mmu_free_page Xiao Guangrong
2011-06-30  8:23 ` [PATCH v3 10/19] KVM: MMU: remove bypass_guest_pf Xiao Guangrong
2011-06-30  8:24 ` [PATCH v3 11/19] KVM: MMU: filter out the mmio pfn from the fault pfn Xiao Guangrong
2011-07-06 17:17   ` Marcelo Tosatti
2011-07-06 19:13     ` Xiao Guangrong
2011-06-30  8:24 ` [PATCH v3 12/19] KVM: MMU: abstract some functions to handle " Xiao Guangrong
2011-06-30  8:25 ` [PATCH v3 13/19] KVM: MMU: introduce the rules to modify shadow page table Xiao Guangrong
2011-06-30  8:25 ` [PATCH v3 14/19] KVM: MMU: clean up spte updating and clearing Xiao Guangrong
2011-07-06 17:39   ` Marcelo Tosatti
2011-07-06 19:18     ` Xiao Guangrong
2011-07-07  8:16       ` Marcelo Tosatti
2011-07-07  9:30         ` Xiao Guangrong
2011-06-30  8:26 ` [PATCH v3 15/19] KVM: MMU: do not need atomicly to set/clear spte Xiao Guangrong
2011-06-30  8:26 ` [PATCH v3 16/19] KVM: MMU: lockless walking shadow page table Xiao Guangrong
2011-07-06 18:08   ` Marcelo Tosatti
2011-07-06 19:26     ` Xiao Guangrong
2011-07-07  8:18       ` Marcelo Tosatti
2011-06-30  8:26 ` [PATCH v3 17/19] KVM: MMU: reorganize struct kvm_shadow_walk_iterator Xiao Guangrong
2011-06-30  8:27 ` [PATCH v3 18/19] KVM: MMU: mmio page fault support Xiao Guangrong
2011-07-06 18:52   ` Marcelo Tosatti
2011-07-06 19:59     ` Xiao Guangrong
2011-07-07  8:49       ` Marcelo Tosatti
2011-06-30  8:28 ` [PATCH v3 19/19] KVM: MMU: trace mmio page fault Xiao Guangrong

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