Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754710AbaLHJn3 (ORCPT ); Mon, 8 Dec 2014 04:43:29 -0500 Received: from terminus.zytor.com ([198.137.202.10]:36544 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752543AbaLHJn1 (ORCPT ); Mon, 8 Dec 2014 04:43:27 -0500 Date: Mon, 8 Dec 2014 01:43:11 -0800 From: tip-bot for Boris Ostrovsky Message-ID: Cc: boris.ostrovsky@oracle.com, hpa@zytor.com, mingo@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@suse.de Reply-To: bp@suse.de, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@kernel.org, boris.ostrovsky@oracle.com, hpa@zytor.com In-Reply-To: <1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.com> References: <1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/microcode] x86, microcode: Don' t initialize microcode code on paravirt Git-Commit-ID: a18a0f6850d4b286a5ebf02cd5b22fe496b86349 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: a18a0f6850d4b286a5ebf02cd5b22fe496b86349 Gitweb: http://git.kernel.org/tip/a18a0f6850d4b286a5ebf02cd5b22fe496b86349 Author: Boris Ostrovsky AuthorDate: Mon, 1 Dec 2014 16:27:44 -0500 Committer: Borislav Petkov CommitDate: Sat, 6 Dec 2014 12:59:03 +0100 x86, microcode: Don't initialize microcode code on paravirt Paravirtual guests are not expected to load microcode into processors and therefore it is not necessary to initialize microcode loading logic. In fact, under certain circumstances initializing this logic may cause the guest to crash. Specifically, 32-bit kernels use __pa_nodebug() macro which does not work in Xen (the code path that leads to this macro happens during resume when we call mc_bp_resume()->load_ucode_ap() ->check_loader_disabled_ap()) Signed-off-by: Boris Ostrovsky Link: http://lkml.kernel.org/r/1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/microcode/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 2ce9051..ebd232d 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -557,7 +557,7 @@ static int __init microcode_init(void) struct cpuinfo_x86 *c = &cpu_data(0); int error; - if (dis_ucode_ldr) + if (paravirt_enabled() || dis_ucode_ldr) return 0; if (c->x86_vendor == X86_VENDOR_INTEL) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/