Message-ID: <3f80e71f-a995-8ad6-b7f2-2b80fefdbd46@intel.com>
Date:   Mon, 27 Feb 2023 08:39:02 -0800
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Subject: Re: [PATCH] x86/CPU/AMD: Make sure EFER[AIBRSE] is set
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To:     Borislav Petkov <bp@alien8.de>
Cc:     Josh Poimboeuf <jpoimboe@kernel.org>,
        Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
        Kim Phillips <kim.phillips@amd.com>, x86@kernel.org,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Joao Martins <joao.m.martins@oracle.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Juergen Gross <jgross@suse.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Tony Luck <tony.luck@intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Alexey Kardashevskiy <aik@amd.com>, kvm@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230124163319.2277355-8-kim.phillips@amd.com>
 <20230224185257.o3mcmloei5zqu7wa@treble> <Y/knUC0s+rg6ef2r@zn.tnic>
 <Y/k/ZXUXOFiBhOiI@zn.tnic> <20230225000931.wrednfun4jifkqau@treble>
 <Y/lUSC5x2ZkTIGu4@zn.tnic> <20230225005221.425yahqvxb57c43x@desk>
 <20230225013202.g7tibykvylprsxs5@treble> <Y/n9XcbnCzWv2Vul@zn.tnic>
 <445daef5-8417-ddbb-abbf-3c5ab38e1c9c@intel.com> <Y/zO7MtvjiVLCiLg@zn.tnic>
From:   Dave Hansen <dave.hansen@intel.com>
In-Reply-To: <Y/zO7MtvjiVLCiLg@zn.tnic>
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On 2/27/23 07:40, Borislav Petkov wrote:
> On Mon, Feb 27, 2023 at 07:25:00AM -0800, Dave Hansen wrote:
>> It will freak some users out, but it does seem like the kind of thing we
>> _want_ a bug report for.
> You mean, something like:
> 
> 	if (spectre_v2_in_ibrs_mode(spectre_v2_enabled) &&
> 	    cpu_has(c, X86_FEATURE_AUTOIBRS))
> 		WARN_ON_ONCE(msr_set_bit(MSR_EFER, _EFER_AUTOIBRS));
> 
> ?

Yep, that looks sane.