linux-kernel - Re: [RFC PATCH v2 5/5] KVM: Unmap pages only when it's indeed protected for NUMA migration

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: <624efb22-8723-d813-0943-edab2870b51d@loongson.cn>
Date:   Wed, 16 Aug 2023 15:53:51 +0800
From:   bibo mao <maobibo@...ngson.cn>
To:     Yan Zhao <yan.y.zhao@...el.com>
Cc:     Sean Christopherson <seanjc@...gle.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        pbonzini@...hat.com, mike.kravetz@...cle.com, apopple@...dia.com,
        jgg@...dia.com, rppt@...nel.org, akpm@...ux-foundation.org,
        kevin.tian@...el.com, david@...hat.com
Subject: Re: [RFC PATCH v2 5/5] KVM: Unmap pages only when it's indeed
 protected for NUMA migration



在 2023/8/16 15:18, Yan Zhao 写道:
> On Wed, Aug 16, 2023 at 03:29:22PM +0800, bibo mao wrote:
>>> Flush must be done before kvm->mmu_lock is unlocked, otherwise,
>>> confusion will be caused when multiple threads trying to update the
>>> secondary MMU.
>> Since tlb flush is delayed after all pte entries are cleared, and currently
>> there is no tlb flush range supported for secondary mmu. I do know why there
>> is confusion before or after kvm->mmu_lock.
> 
> Oh, do you mean only do kvm_unmap_gfn_range() in .invalidate_range_end()?
yes, it is just sketchy thought for numa balance scenery, 
do kvm_unmap_gfn_range() in invalidate_range_end rather than
invalidate_range_start.
 
> Then check if PROT_NONE is set in primary MMU before unmap?
> Looks like a good idea, I need to check if it's feasible.
> Thanks!
> 
>