From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 22/27] KVM: MMU: Refactor mmu_alloc_roots function
Date: Wed, 08 Sep 2010 10:16:59 +0300
Message-ID: <4C87386B.2030109@redhat.com>
References: <1283788566-29186-1-git-send-email-joerg.roedel@amd.com> <1283788566-29186-23-git-send-email-joerg.roedel@amd.com> <20100907203952.GA14489@amt.cnet>
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Cc: Joerg Roedel <joerg.roedel@amd.com>,
	Alexander Graf <agraf@suse.de>, joro@8bytes.org,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
To: Marcelo Tosatti <mtosatti@redhat.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20100907203952.GA14489@amt.cnet>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: kvm.vger.kernel.org

  On 09/07/2010 11:39 PM, Marcelo Tosatti wrote:
>
>> @@ -2406,16 +2441,11 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
>>   			root_gfn = pdptr>>  PAGE_SHIFT;
>>   			if (mmu_check_root(vcpu, root_gfn))
>>   				return 1;
>> -		} else if (vcpu->arch.mmu.root_level == 0)
>> -			root_gfn = 0;
>> -		if (vcpu->arch.mmu.direct_map) {
>> -			direct = 1;
>> -			root_gfn = i<<  30;
>>   		}
>>   		spin_lock(&vcpu->kvm->mmu_lock);
>>   		kvm_mmu_free_some_pages(vcpu);
>>   		sp = kvm_mmu_get_page(vcpu, root_gfn, i<<  30,
>> -				      PT32_ROOT_LEVEL, direct,
>> +				      PT32_ROOT_LEVEL, 0,
>>   				      ACC_ALL, NULL);
> Should not write protect the gfn for nonpaging mode.
>

nonpaging mode should have direct_map set, so wouldn't enter this path 
at all.

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