linux-kernel - Re: [PATCH v3 13/15] KVM: MMU: locklessly write-protect the page

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] [thread-next>] [day] [month] [year] [list]

Message-ID: <5268E73C.7030302@linux.vnet.ibm.com>
Date:	Thu, 24 Oct 2013 17:24:12 +0800
From:	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>
To:	Gleb Natapov <gleb@...hat.com>
CC:	avi.kivity@...il.com, mtosatti@...hat.com, pbonzini@...hat.com,
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: Re: [PATCH v3 13/15] KVM: MMU: locklessly write-protect the page

On 10/24/2013 05:17 PM, Gleb Natapov wrote:

>>  
>> -/**
>> - * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages
>> +static void __rmap_write_protect_lockless(u64 *sptep)
>> +{
>> +	u64 spte;
>> +
>> +retry:
>> +	/*
>> +	 * Note we may partly read the sptep on 32bit host, however, we
>> +	 * allow this case because:
>> +	 * - we do not access the page got from the sptep.
>> +	 * - cmpxchg64 can detect that case and avoid setting a wrong value
>> +	 *   to the sptep.
>> +	 */
>> +	spte = *rcu_dereference(sptep);
>> +	if (unlikely(!is_last_spte(spte) || !is_writable_pte(spte)))
> is_last_spte gets two parameters.

In patch [PATCH v3 12/15] KVM: MMU: check last spte with unawareness of mapping level,
we have removed the 'level' from the parameter list.

--
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/