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Subject: Re: [PATCH RFC v2 0/6] x86: Disabling PTI in compatibility mode
To: Nadav Amit <namit@vmware.com>, Ingo Molnar <mingo@redhat.com>
References: <20180215163602.61162-1-namit@vmware.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Willy Tarreau <w@1wt.eu>,
        Nadav Amit <nadav.amit@gmail.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org
From: Dave Hansen <dave.hansen@linux.intel.com>
Message-ID: <27a0082c-fadb-792a-740e-70932d51f1b5@linux.intel.com>
Date: Thu, 15 Feb 2018 16:21:12 -0800
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On 02/15/2018 08:35 AM, Nadav Amit wrote:
> I removed the PTI disabling while SMEP is unsupported, although I
> must admit I did not fully understand why it is required.

Do you mean you don't fully understand how PTI gives SMEP-like behavior
on non-SMEP hardware?