From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758303AbeAHXoh (ORCPT + 1 other); Mon, 8 Jan 2018 18:44:37 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:51303 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758287AbeAHXof (ORCPT ); Mon, 8 Jan 2018 18:44:35 -0500 Date: Tue, 9 Jan 2018 00:44:30 +0100 (CET) From: Thomas Gleixner To: Pavel Machek cc: linux-kernel@vger.kernel.org, r.marek@assembler.cz, ricardo.neri-calderon@linux.intel.com, rkrcmar@redhat.com, Janakarajan.Natarajan@amd.com, bp@suse.de, x86@kernel.org, hpa@zytor.com, mingo@redhat.com, Linus Torvalds Subject: Re: [PATCH] clarify how insecure CPU is In-Reply-To: <20180108230355.GA25349@amd> Message-ID: References: <20180108201017.GA20588@amd> <20180108230355.GA25349@amd> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Tue, 9 Jan 2018, Pavel Machek wrote: > On Mon 2018-01-08 21:27:25, Thomas Gleixner wrote: > > On Mon, 8 Jan 2018, Pavel Machek wrote: > > > > > > > > First, what is going on with X86_BUG_AMD_E400 and X86_BUG_AMD_APIC_C1E > > > ? They seem to refer to the same bug, perhaps comment should mention > > > that? (Do we need two flags for one bug?) > > > > > > Next, maybe X86_BUG_CPU_INSECURE is a bit too generic? This seems to > > > address "Meltdown" problem, but not "Spectre". Should it be limited to > > > PPro and newer Intel CPUs? > > > > > > Should another erratum be added for "Spectre"? This is present even on > > > AMD CPUs, but should not be present in 486, maybe Pentium, and some > > > Atom chips? > > > > > > Plus... is this reasonable interface? > > > > > > bugs : cpu_insecure > > > > We've renamed it to meltdown already and added spectre_v1/v2 bits for the > > rest of the mess. > > Could you explain (best with code comment) what is going on with > X86_BUG_AMD_E400 and X86_BUG_AMD_APIC_C1E ? They seem to refer to the > same bug. Sorry, that;s really not the time for this. > Plus, as I explained: "bugs: meltdown, spectre" seems to be bad idea, > as userland application can not easily tell between "no bug" and "bug > not known to kernel". https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de https://lkml.kernel.org/r/20180107214913.177414879@linutronix.de Thanks, tglx