From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932350AbdJ0RJy (ORCPT ); Fri, 27 Oct 2017 13:09:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46492 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932190AbdJ0RJu (ORCPT ); Fri, 27 Oct 2017 13:09:50 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 13E46C0587C0 Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=vkuznets@redhat.com From: Vitaly Kuznetsov To: Boris Petkov Cc: Dou Liyang , linux-kernel@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, jgross@suse.com, boris.ostrovsky@oracle.com, luto@kernel.org Subject: Re: [PATCH][tip] x86/paravirt: Make the virt_spin_lock_key setup after jump_label_init() References: <1509120120-5386-1-git-send-email-douly.fnst@cn.fujitsu.com> Date: Fri, 27 Oct 2017 19:09:32 +0200 In-Reply-To: (Boris Petkov's message of "Fri, 27 Oct 2017 18:52:03 +0200") Message-ID: <87bmkszfeb.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 27 Oct 2017 17:09:50 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Boris Petkov writes: > On October 27, 2017 6:02:00 PM GMT+02:00, Dou Liyang wrote: >>Commit: >> >> 9043442b43b1 ("locking/paravirt: Use new static key for controlling >> call of virt_spin_lock()") >> >>set the static virt_spin_lock_key to a value before jump_label_init() >>has been called, which will result in a WARN(). >> >>Move the native_pv_lock_init() into xx_smp_prepare_cpus(). Make the >>setup later to avoid the WARN(). >> >>Reported-by: Juergen Gross >>Suggested-by: Juergen Gross >>Signed-off-by: Dou Liyang >>--- >> arch/x86/kernel/smpboot.c | 3 ++- >> arch/x86/xen/smp_pv.c | 2 ++ >> arch/x86/xen/spinlock.c | 6 ++++-- >> 3 files changed, 8 insertions(+), 3 deletions(-) >> >>diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c >>index aed1460..6b1335a 100644 >>--- a/arch/x86/kernel/smpboot.c >>+++ b/arch/x86/kernel/smpboot.c >>@@ -1323,6 +1323,8 @@ void __init native_smp_prepare_cpus(unsigned int >>max_cpus) >> pr_info("CPU0: "); >> print_cpu_info(&cpu_data(0)); >> >>+ native_pv_lock_init(); >>+ >> uv_system_init(); >> >> set_mtrr_aps_delayed_init(); >>@@ -1350,7 +1352,6 @@ void __init native_smp_prepare_boot_cpu(void) >> /* already set me in cpu_online_mask in boot_cpu_init() */ >> cpumask_set_cpu(me, cpu_callout_mask); >> cpu_set_state_online(me); >>- native_pv_lock_init(); >> } >> >> void __init native_smp_cpus_done(unsigned int max_cpus) >>diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c >>index 5147140..570b2bc 100644 >>--- a/arch/x86/xen/smp_pv.c >>+++ b/arch/x86/xen/smp_pv.c >>@@ -236,6 +236,8 @@ static void __init xen_pv_smp_prepare_cpus(unsigned >>int max_cpus) >> xen_raw_printk(m); >> panic(m); >> } >>+ native_pv_lock_init(); >>+ >> xen_init_lock_cpu(0); >> >> smp_store_boot_cpu_info(); >>diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c >>index e8ab80a..1e1462d 100644 >>--- a/arch/x86/xen/spinlock.c >>+++ b/arch/x86/xen/spinlock.c >>@@ -81,8 +81,11 @@ void xen_init_lock_cpu(int cpu) >> int irq; >> char *name; >> >>- if (!xen_pvspin) >>+ if (!xen_pvspin) { >>+ if (cpu == 0) >>+ static_branch_disable(&virt_spin_lock_key); > > This is assuming CPU 0 is the boot cpu. I think you want boot_cpu_data.cpu_index here or whatever is used on xen to identify the BSP reliably. It seems both PV and PVHVM call xen_init_lock_cpu(0) so 0 here is Linux's idea of CPU id, not Xen's. In case Xen's idea is needed xen_vcpu_id mapping should be used. But I don't think it's the case here. -- Vitaly