From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:33812 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753093AbeFEREv (ORCPT ); Tue, 5 Jun 2018 13:04:51 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "dwmw@amazon.co.uk, boris.ostrovsky@oracle.com, Juergen Gross" , Juergen Gross Subject: [PATCH 4.9 15/61] x86/amd: revert commit 944e0fc51a89c9827b9 Date: Tue, 5 Jun 2018 19:01:36 +0200 Message-Id: <20180605170118.591023264@linuxfoundation.org> In-Reply-To: <20180605170117.643936916@linuxfoundation.org> References: <20180605170117.643936916@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross Revert commit 944e0fc51a89c9827b98813d65dc083274777c7f ("x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen") as it is lacking a prerequisite patch and is making things worse. Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/amd.c | 5 ++--- arch/x86/xen/enlighten.c | 4 +++- 2 files changed, 5 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -857,9 +857,8 @@ static void init_amd(struct cpuinfo_x86 if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM)) set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH); - /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */ - if (!cpu_has(c, X86_FEATURE_XENPV)) - set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); + /* AMD CPUs don't reset SS attributes on SYSRET */ + set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); } #ifdef CONFIG_X86_32 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1980,8 +1980,10 @@ EXPORT_SYMBOL_GPL(xen_hvm_need_lapic); static void xen_set_cpu_features(struct cpuinfo_x86 *c) { - if (xen_pv_domain()) + if (xen_pv_domain()) { + clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); set_cpu_cap(c, X86_FEATURE_XENPV); + } } static void xen_pin_vcpu(int cpu)