Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757110AbaGHTvA (ORCPT ); Tue, 8 Jul 2014 15:51:00 -0400 Received: from mail.kernel.org ([198.145.19.201]:34551 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756339AbaGHTu5 (ORCPT ); Tue, 8 Jul 2014 15:50:57 -0400 From: konrad@kernel.org To: xen-devel@lists.xenproject.org, david.vrabel@citrix.com, boris.ostrovsky@oracle.com, linux-kernel@vger.kernel.org Cc: Konrad Rzeszutek Wilk Subject: [PATCH v2] xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests. Date: Tue, 8 Jul 2014 16:52:25 -0400 Message-Id: <1404852745-25187-1-git-send-email-konrad@kernel.org> X-Mailer: git-send-email 1.7.7.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Konrad Rzeszutek Wilk By default when CONFIG_XEN and CONFIG_XEN_PVHVM kernels are run, they will enable the PV extensions (drivers, interrupts, timers, etc) - which is perfect. However, in some cases (kexec not fully wokring, benchmarking) we want to disable Xen PV extensions. As such introduce the 'xen_nopv' parameter that will do it. Signed-off-by: Konrad Rzeszutek Wilk --- [v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.] --- Documentation/kernel-parameters.txt | 4 ++++ arch/x86/xen/enlighten.c | 13 +++++++++++++ 2 files changed, 17 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1b9aa8..5dcfa6e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3691,6 +3691,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Disables the ticketlock slowpath using Xen PV optimizations. + xen_nopv [X86,XEN] + Disables the PV optimizations forcing the guest to run + as generic HVM guest with no PV drivers. + xirc2ps_cs= [NET,PCMCIA] Format: ,,,,,[,[,[,]]] diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index e220197..7aa59ef 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1930,10 +1930,21 @@ static void __init xen_hvm_guest_init(void) #endif } +static bool xen_nopv = false; +static __init int xen_parse_nopv(char *arg) +{ + xen_nopv = true; + return 0; +} +early_param("xen_nopv", xen_parse_nopv); + static uint32_t __init xen_hvm_platform(void) { uint32_t eax, ebx, ecx, edx, base; + if (xen_nopv) + return 0; + if (xen_pv_domain()) return 0; @@ -1953,6 +1964,8 @@ static uint32_t __init xen_hvm_platform(void) bool xen_hvm_need_lapic(void) { + if (xen_nopv) + return false; if (xen_pv_domain()) return false; if (!xen_hvm_domain()) -- 1.7.7.6 -- 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/