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  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]
Date:   Fri, 22 Oct 2021 10:11:01 +0800
From:   Lai Jiangshan <jiangshanlai@...il.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     LKML <linux-kernel@...r.kernel.org>, kvm@...r.kernel.org,
        Lai Jiangshan <laijs@...ux.alibaba.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        X86 ML <x86@...nel.org>, "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH 2/4] KVM: X86: Cache CR3 in prev_roots when PCID is disabled

On Fri, Oct 22, 2021 at 1:43 AM Paolo Bonzini <pbonzini@...hat.com> wrote:

>
>           * If CR4.PCIDE is changed 1 -> 0, the guest TLB must be flushed.
>           * If CR4.PCIDE is changed 0 -> 1, there is no need to flush the TLB
>           * according to the SDM; however, stale prev_roots could be reused
>           * reused incorrectly by MOV to CR3 with NOFLUSH=1, so we free them
>           * all.  KVM_REQ_MMU_RELOAD is fit for the both cases; it
>           * is slow, but changing CR4.PCIDE is a rare case.
>

There is a double "reused" separated by "\".

>
>
> Can you confirm the above comments are accurate?
>

Yes, they are better and consistent with what I meant, only one redundant
"reused" in the comments.

thanks
Lai

Powered by blists - more mailing lists