From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757009AbbCCQjt (ORCPT ); Tue, 3 Mar 2015 11:39:49 -0500 Received: from mail.skyhub.de ([78.46.96.112]:48897 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756081AbbCCQjs (ORCPT ); Tue, 3 Mar 2015 11:39:48 -0500 Date: Tue, 3 Mar 2015 17:38:37 +0100 From: Borislav Petkov To: Daniel J Blueman Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Quentin Casasnovas , Steffen Persvold , linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH] x86: Unbreak early processor microcode loading Message-ID: <20150303163836.GC25768@pd.tnic> References: <1425395444-20969-1-git-send-email-daniel@numascale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1425395444-20969-1-git-send-email-daniel@numascale.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 03, 2015 at 11:10:44PM +0800, Daniel J Blueman wrote: > The changes in 871b72dd "x86: microcode: use smp_call_function_single instead > of set_cpus_allowed, cleanup of synchronization logic" introduced a check > that prevents built-in microcode from being loaded before init starts. > > Conditionalise it on early microcode loading, so we get the expected behaviour > when early microcode loading is enabled, and when it is not. This has potential > importance as BIOSes often don't load the current microcode. ... probably because they don't have it. Which is also the main reason for the existence of this microcode loader btw :) > > Signed-off-by: Daniel J Blueman > --- > arch/x86/kernel/cpu/microcode/core.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c > index 36a8361..fa7f9fc 100644 > --- a/arch/x86/kernel/cpu/microcode/core.c > +++ b/arch/x86/kernel/cpu/microcode/core.c > @@ -391,9 +391,11 @@ static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw) > if (collect_cpu_info(cpu)) > return UCODE_ERROR; > > +#if !defined(CONFIG_MICROCODE_AMD_EARLY) && !defined(CONFIG_MICROCODE_INTEL_EARLY) > /* --dimm. Trigger a delayed update? */ > if (system_state != SYSTEM_RUNNING) > return UCODE_NFOUND; > +#endif Ok, let me try to understand this correctly: where is this microcode built in, into the kernel? If yes, you should consider enabling the early loading method and build in the microcode into the initrd, see Documentation/x86/early-microcode.txt This is the preferred method as we're applying the microcode much earlier. Back to you. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --