From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753317AbeBKLqt (ORCPT ); Sun, 11 Feb 2018 06:46:49 -0500 Received: from mail-wr0-f195.google.com ([209.85.128.195]:33035 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753065AbeBKLqr (ORCPT ); Sun, 11 Feb 2018 06:46:47 -0500 X-Google-Smtp-Source: AH8x227T3OawUnF9/eZCHOfjMKkBSShlUM2SkLSX+masAEzkFrePzXDTa6oFldzUqiO1S4qi53+pNQ== Date: Sun, 11 Feb 2018 12:46:43 +0100 From: Ingo Molnar To: David Woodhouse Cc: tglx@linutronix.de, karahmed@amazon.de, sironi@amazon.de, x86@kernel.org, kvm@vger.kernel.org, torvalds@linux-foundation.org, pbonzini@redhat.com, linux-kernel@vger.kernel.org, bp@alien8.de, peterz@infradead.org, jmattson@google.com, rkrcmar@redhat.com, arjan.van.de.ven@intel.com, dave.hansen@intel.com Subject: Re: [PATCH v2 6/6] x86/speculation: Use IBRS if available before calling into firmware Message-ID: <20180211114643.mek3zydznbernsdr@gmail.com> References: <1518305967-31356-1-git-send-email-dwmw@amazon.co.uk> <1518305967-31356-7-git-send-email-dwmw@amazon.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1518305967-31356-7-git-send-email-dwmw@amazon.co.uk> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * David Woodhouse wrote: > Retpoline means the kernel is safe because it has no indirect branches. > But firmware isn't, so use IBRS for firmware calls if it's available. Ok, this approach looks good to me in principle, but: > --- a/arch/x86/include/asm/apm.h > +++ b/arch/x86/include/asm/apm.h > @@ -7,6 +7,8 @@ > #ifndef _ASM_X86_MACH_DEFAULT_APM_H > #define _ASM_X86_MACH_DEFAULT_APM_H > > +#include I cannot see this header file upstream anywhere, nor in any other patch in my mbox - is there some dependency that has to be applied first? Thanks, Ingo