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Subject: Re: [PATCH] KVM: x86: VMX: Make smaller physical guest address space
 support user-configurable
To:     Jim Mattson <jmattson@google.com>
Cc:     Mohammed Gamal <mgamal@redhat.com>, joro@8bytes.org,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        sean.j.christopherson@intel.com, vkuznets@redhat.com,
        wanpengli@tencent.com
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 <CALMp9eTHbhwfdq4Be=XcUG9z82KK8AapQeVmsdH=mGdQ_Yt2ug@mail.gmail.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <79277092-a5b8-ebb0-8a9f-e41d094ed05b@redhat.com>
Date:   Wed, 23 Sep 2020 17:19:46 +0200
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On 23/09/20 16:32, Jim Mattson wrote:
> You don’t buy my argument that this should be per-VM, then? I’d bet that
> we have very close to 0 customers who care about emulating the reserved
> bits properly for 46-but wide VMs, but there may be someone out there
> using shadow paging in a nested kvm. 
> 

I do buy it but I prefer not to have a released version of Linux where
this is enabled by default.  I procrastinated hoping to cobble something
together but I didn't have time.

Paolo