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Date:   Wed, 9 Oct 2019 09:36:00 -0700
From:   Sean Christopherson <sean.j.christopherson@intel.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
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        linux-kernel@vger.kernel.org, Reto Buerki <reet@codelabs.ch>,
        Liran Alon <liran.alon@oracle.com>
Subject: Re: [PATCH v2 5/8] KVM: x86: Add WARNs to detect out-of-bounds
 register indices
Message-ID: <20191009163600.GA19952@linux.intel.com>
References: <20190927214523.3376-1-sean.j.christopherson@intel.com>
 <20190927214523.3376-6-sean.j.christopherson@intel.com>
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On Wed, Oct 09, 2019 at 12:50:44PM +0200, Paolo Bonzini wrote:
> On 27/09/19 23:45, Sean Christopherson wrote:
> > Open code the RIP and RSP accessors so as to avoid pointless overhead of
> > WARN_ON_ONCE().
> 
> Is there actually an overhead here?  It is effectively WARN_ON_ONCE(0)
> which should be compiled out just fine.

Doh, you're correct, it does get compiled out.