From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 1 Dec 2014 17:28:27 -0800 From: Greg KH To: Boris Ostrovsky Cc: bp@suse.de, x86@kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, david.vrabel@citrix.com, konrad.wilk@oracle.com Subject: Re: [PATCH] x86, microcode: Don't initialize microcode code on paravirt Message-ID: <20141202012827.GA22525@kroah.com> References: <1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Mon, Dec 01, 2014 at 04:27:44PM -0500, Boris Ostrovsky wrote: > 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 > --- > arch/x86/kernel/cpu/microcode/core.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly.