linux-kernel - Re: [PATCH v3 31/37] KVM: x86/mmu: Add separate override for MMU sync during fast CR3 switch

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: <1227ad9e-0b91-f9a7-10b0-b02203ba52ca@redhat.com>
Date:   Tue, 24 Mar 2020 12:07:50 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Ben Gardon <bgardon@...gle.com>,
        Junaid Shahid <junaids@...gle.com>,
        Liran Alon <liran.alon@...cle.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        John Haxby <john.haxby@...cle.com>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Tom Lendacky <thomas.lendacky@....com>
Subject: Re: [PATCH v3 31/37] KVM: x86/mmu: Add separate override for MMU sync
 during fast CR3 switch

On 20/03/20 22:28, Sean Christopherson wrote:
> Add a separate "skip" override for MMU sync, a future change to avoid
> TLB flushes on nested VMX transitions may need to sync the MMU even if
> the TLB flush is unnecessary.
> 
> Suggested-by: Paolo Bonzini <pbonzini@...hat.com>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>

I added a WARN_ON(skip_tlb_flush && !skip_mmu_sync); which could help
catching misordered parameters.

Paolo