Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190814070403.6588-1-weijiang.yang@intel.com>
 <20190814070403.6588-6-weijiang.yang@intel.com> <87a7cbapdw.fsf@vitty.brq.redhat.com>
 <20190815134329.GA11449@local-michael-cet-test>
In-Reply-To: <20190815134329.GA11449@local-michael-cet-test>
From:   Jim Mattson <jmattson@google.com>
Date:   Thu, 15 Aug 2019 09:25:41 -0700
Message-ID: <CALMp9eTGXDDfVspFwFyEhagg9sdnqZqzSQhDksT0bkKzVNGSqw@mail.gmail.com>
Subject: Re: [PATCH RESEND v4 5/9] KVM: VMX: Add init/set/get functions for SPP
To:     Yang Weijiang <weijiang.yang@intel.com>
Cc:     Vitaly Kuznetsov <vkuznets@redhat.com>,
        kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        yu.c.zhang@intel.com, alazar@bitdefender.com,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Aug 15, 2019 at 6:41 AM Yang Weijiang <weijiang.yang@intel.com> wrote:

> Hi, Vitaly,
> After looked into the issue and others, I feel to make SPP co-existing
> with nested VM is not good, the major reason is, L1 pages protected by
> SPP are transparent to L1 VM, if it launches L2 VM, probably the
> pages would be allocated to L2 VM, and that will bother to L1 and L2.
> Given the feature is new and I don't see nested VM can benefit
> from it right now, I would like to make SPP and nested feature mutually
> exclusive, i.e., detecting if the other part is active before activate one
> feature,what do you think of it?
> thanks!

How do you propose making the features mutually exclusive?