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From:   Eric Hankland <ehankland@google.com>
Date:   Wed, 5 Jun 2019 14:35:37 -0700
Message-ID: <CAOyeoRXFAQNNWRiHNtK3n17V0owBVNyKdv75xjt08Q_pC+XOXg@mail.gmail.com>
Subject: Re: [PATCH v1] KVM: x86: PMU Whitelist
To:     Wei Wang <wei.w.wang@intel.com>
Cc:     Cfir Cohen <cfir@google.com>, Paolo Bonzini <pbonzini@redhat.com>,
        rkrcmar@redhat.com, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, Stephane Eranian <eranian@google.com>
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>> Right - I'm aware there are other ways of detecting this - it's still
>> a class of events that some people don't want to surface. I'll ask if
>> there are any better examples.

I asked and it sounds like we are treating all events as potentially
insecure until they've been reviewed. If Intel were to publish
official (reasonably substantiated) guidance stating that the PMU is
secure, then I think we'd be happy without such a safeguard in place,
but short of that I think we want to err on the side of caution.

Eric