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Date:   Thu, 22 Dec 2022 14:03:57 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     "Li, Xin3" <xin3.li@intel.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
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        "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
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        "Christopherson,, Sean" <seanjc@google.com>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "Shankar, Ravi V" <ravi.v.shankar@intel.com>
Subject: Re: [RFC PATCH 14/32] x86/fred: header file with FRED definitions
Message-ID: <Y6RVvRg20Xc6IR4k@hirez.programming.kicks-ass.net>
References: <20221220063658.19271-1-xin3.li@intel.com>
 <20221220063658.19271-15-xin3.li@intel.com>
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 <BN6PR1101MB21615569318BD964A2855F44A8EB9@BN6PR1101MB2161.namprd11.prod.outlook.com>
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Precedence: bulk

On Wed, Dec 21, 2022 at 02:58:06AM +0000, Li, Xin3 wrote:

> > > +/* Flags above the CS selector (regs->csl) */
> > > +#define FRED_CSL_ENABLE_NMI		_BITUL(28)
> > > +#define FRED_CSL_ALLOW_SINGLE_STEP	_BITUL(25)
> > > +#define FRED_CSL_INTERRUPT_SHADOW	_BITUL(24)
> > 
> > What's the state of IBT WAIT-FOR-ENDBR vs this? That really should also get a
> > high CS bit.
> 
> FRED does provide more possibilities :)

That's not an answer. IBT has a clear defect and FRED *should* fix it.