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Date:   Mon, 27 May 2019 12:30:03 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Tao Xu <tao3.xu@intel.com>
Cc:     pbonzini@redhat.com, rkrcmar@redhat.com, corbet@lwn.net,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
        sean.j.christopherson@intel.com, x86@kernel.org,
        kvm@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, jingqi.liu@intel.com
Subject: Re: [PATCH v2 1/3] KVM: x86: add support for user wait instructions
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On Fri, May 24, 2019 at 03:56:35PM +0800, Tao Xu wrote:
> This patch adds support for UMONITOR, UMWAIT and TPAUSE instructions
> in kvm, and by default dont't expose it to kvm and provide a capability
> to enable it.

I'm thinking this should be conditional on the guest being a 1:1 guest,
and I also seem to remember we have bits for that already -- they were
used to disable paravirt spinlocks for example.