linux-kernel - Re: [PATCH v2] KVM: MMU: optimize pte write path if don't have protected sp

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] [day] [month] [year] [list]

Message-ID: <4DCA7A9B.6060305@cn.fujitsu.com>
Date:	Wed, 11 May 2011 20:01:31 +0800
From:	Xiao Guangrong <xiaoguangrong@...fujitsu.com>
To:	Avi Kivity <avi@...hat.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: Re: [PATCH v2] KVM: MMU: optimize pte write path if don't have protected
 sp

On 05/11/2011 07:28 PM, Avi Kivity wrote:
> On 05/11/2011 05:44 AM, Xiao Guangrong wrote:
>> Simply return from kvm_mmu_pte_write path if no shadow page is
>> write-protected, then we can avoid to walk all shadow pages and hold
>> mmu-lock
>>
>> @@ -1038,8 +1038,10 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
>>       hlist_del(&sp->hash_link);
>>       list_del(&sp->link);
>>       free_page((unsigned long)sp->spt);
>> -    if (!sp->role.direct)
>> +    if (!sp->role.direct) {
>>           free_page((unsigned long)sp->gfns);
>> +        atomic_dec(&kvm->arch.indirect_shadow_pages);
>> +    }
>>       kmem_cache_free(mmu_page_header_cache, sp);
>>       kvm_mod_used_mmu_pages(kvm, -1);
>>   }
>> @@ -1536,6 +1538,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
>>               kvm_sync_pages(vcpu, gfn);
>>
>>           account_shadowed(vcpu->kvm, gfn);
>> +        atomic_inc(&vcpu->kvm->arch.indirect_shadow_pages);
>>       }
> 
> Better in account_shadowed()/unaccount_shadowed(), no?
> 

Yes, will fix. thanks for your reminder!

--
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/