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Date:   Thu, 22 Nov 2018 22:17:44 +0100 (CET)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Borislav Petkov <bp@alien8.de>
cc:     Josh Poimboeuf <jpoimboe@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
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        Peter Zijlstra <peterz@infradead.org>,
        Andrew Lutomirski <luto@kernel.org>,
        Jiri Kosina <jkosina@suse.cz>, thomas.lendacky@amd.com,
        Andrea Arcangeli <aarcange@redhat.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Andi Kleen <ak@linux.intel.com>, dave.hansen@intel.com,
        Casey Schaufler <casey.schaufler@intel.com>,
        "Mallick, Asit K" <asit.k.mallick@intel.com>,
        "Van De Ven, Arjan" <arjan@linux.intel.com>, jcm@redhat.com,
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        david.c.stewart@intel.com, Kees Cook <keescook@chromium.org>,
        Tim Chen <tim.c.chen@linux.intel.com>
Subject: Re: [patch 01/24] x86/speculation: Update the TIF_SSBD comment
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On Thu, 22 Nov 2018, Borislav Petkov wrote:
> On Thu, Nov 22, 2018 at 11:30:04AM -0600, Josh Poimboeuf wrote:
> > But it does describe its purpose, especially in relation to the
> > 'spectre_v2=' option.
> 
> Sure, but the thing I'm proposing
> 
> spectre_v2_task_isol=
> 
> describes it more precisely, IMHO. :)
> 
> I.e., "enable/disable spectre v2 task isolation".
> 
> > Previously 'spectre_v2=' might have been more appropriately named
> > 'spectre_v2_kernel=' because it only protected the kernel from Spectre
> > v2 attacks.  Now with these new patches, 'spectre_v2=on' will protect
> > the entire system.
> 
> Hmmm, crazy idea: can we extend the options of spectre_v2= nstead?
> 
> spectre_v2=user_isolation,...
> spectre_v2=kernel,...
> spectre_v2=task_isolation,...
> 
> and so on?
> 
> This way we can do a couple of option switches in one go.

That's results in a huge parser state space and changes the existing
interface. We stay with the separate option.

Thanks,

	tglx