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Subject: Re: [PATCH RFC 2/3] x86/kvm/hyper-v: move VMX controls sanitization
 out of nested_enable_evmcs()
To:     Sean Christopherson <sean.j.christopherson@intel.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>
Cc:     Liran Alon <liran.alon@oracle.com>, kvm@vger.kernel.org,
        Jim Mattson <jmattson@google.com>,
        linux-kernel@vger.kernel.org, Roman Kagan <rkagan@virtuozzo.com>
References: <20200115171014.56405-1-vkuznets@redhat.com>
 <20200115171014.56405-3-vkuznets@redhat.com>
 <20200115232738.GB18268@linux.intel.com>
 <C6C4003E-0ADD-42A5-A580-09E06806E160@oracle.com>
 <877e1riy1o.fsf@vitty.brq.redhat.com>
 <20200116161928.GC20561@linux.intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <0c3d32c1-7544-2370-f645-030bed55db83@redhat.com>
Date:   Sat, 18 Jan 2020 22:42:31 +0100
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On 16/01/20 17:19, Sean Christopherson wrote:
> Why not just do this in Qemu?  IMO that's not a major ask, e.g. Qemu is
> doing a decent amount of manual adjustment anyways.  And Qemu isn't even
> using the result of KVM_GET_MSRS so I don't think it's fair to say this is
> solely KVM's fault.

IMHO the features should stay available in case the guest chooses not to
use eVMCS.  A guest that uses eVMCS should know which features it cannot
use and not enable them.

Paolo