linux-kernel - Re: [PATCH] KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE

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Message-ID: <CALMp9eQzZmV5k6qjHZgJYnKv3c7VPB7qEDJRLREW_NNUo=H1zA@mail.gmail.com>
Date:   Thu, 24 Sep 2020 14:48:03 -0700
From:   Jim Mattson <jmattson@...gle.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Joerg Roedel <joro@...tes.org>, kvm list <kvm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Peter Shier <pshier@...gle.com>,
        Oliver Upton <oupton@...gle.com>
Subject: Re: [PATCH] KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE

On Wed, Sep 23, 2020 at 2:54 PM Sean Christopherson
<sean.j.christopherson@...el.com> wrote:
>
> Reset the MMU context during kvm_set_cr4() if SMAP or PKE is toggled.
> Recent commits to (correctly) not reload PDPTRs when SMAP/PKE are
> toggled inadvertantly skipped the MMU context reset due to the mask
> of bits that triggers PDPTR loads also being used to trigger MMU context
> resets.
>
> Fixes: 427890aff855 ("kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode")
> Fixes: cb957adb4ea4 ("kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode")
> Cc: Jim Mattson <jmattson@...gle.com>
> Cc: Peter Shier <pshier@...gle.com>
> Cc: Oliver Upton <oupton@...gle.com>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>

Thanks for the fix!

Reviewed-by: Jim Mattson <jmattson@...gle.com>