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Date:   Fri, 15 Jun 2018 15:38:37 -0400
From:   Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To:     Thomas Gleixner <tglx@linutronix.de>, alexandre.chartre@oracle.com
Cc:     Tom Lendacky <thomas.lendacky@amd.com>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org,
        andrew.cooper3@citrix.com, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@suse.de>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Kees Cook <keescook@chromium.org>,
        KarimAllah Ahmed <karahmed@amazon.de>
Subject: Re: [PATCH v1 3/3] x86/bugs: Switch the selection of mitigation from
 CPU vendor to CPU features
Message-ID: <20180615193837.GA20921@char.us.oracle.com>
References: <20180601145921.9500-1-konrad.wilk@oracle.com>
 <20180601145921.9500-4-konrad.wilk@oracle.com>
 <2a3e0323-7086-f764-1a3b-7ce4891e8784@amd.com>
 <20180611140116.GA26199@char.us.oracle.com>
 <5090fe69-61fd-99cb-f9d0-908cd6250d25@amd.com>
 <alpine.DEB.2.21.1806152057020.1582@nanos.tec.linutronix.de>
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On Fri, Jun 15, 2018 at 08:57:40PM +0200, Thomas Gleixner wrote:
> On Tue, 12 Jun 2018, Tom Lendacky wrote:
> > On 6/11/2018 9:01 AM, Konrad Rzeszutek Wilk wrote:
> > >> I think you will have to keep the case statements and explicitly check for
> > >> X86_FEATURE_AMD_SSBD before using SPEC_CTRL.
> > > 
> > > .. we could or alternatively add an extra check for X86_FEATURE_AMD_SSBD ?
> > 
> > Whichever you feel is best, so long as we only use SPEC_CTRL for SSBD on
> > AMD when X86_FEATURE_AMD_SSBD is present.
> 
> Is there anyone working on a fix or has this been forgotten?

I have it on my TODO.

But a bit busy with the fpu lazy so will get to it done next week.

Maybe along with the X86_FEATURE_IA32_ARCH_CAPS Bit(1): IBRS_ALL to disable
retpoline on those machines.

CCing Alex

> 
> Thanks,
> 
> 	tglx