From patchwork Wed May 3 20:20:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Ostrovsky X-Patchwork-Id: 9710357 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6DC2760351 for ; Wed, 3 May 2017 20:23:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 590C726D08 for ; Wed, 3 May 2017 20:23:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4D90728648; Wed, 3 May 2017 20:23:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id CFDB426D08 for ; Wed, 3 May 2017 20:23:45 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d60m5-0000BS-Ea; Wed, 03 May 2017 20:21:25 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d60m4-0000BM-Rx for xen-devel@lists.xenproject.org; Wed, 03 May 2017 20:21:24 +0000 Received: from [85.158.143.35] by server-4.bemta-6.messagelabs.com id C0/1F-02956-4CB3A095; Wed, 03 May 2017 20:21:24 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrCLMWRWlGSWpSXmKPExsXSO6nOVfewNVe kwcJzmhbft0xmcmD0OPzhCksAYxRrZl5SfkUCa8bWdwdYCz7xVrx+0sLawPiBu4uRi0NIYBKT xO1Vj5kgnF+MEn+fL4JyNjBKbL5wEsrZzSjx+l0jcxcjJwebgJHE2aPTGUFsEQFhieNHt4HFm QXKJCa+nAVmCwtESRxY95a1i5GDg0VAVaK10xkkzCvgJXFm9TZWEFtCQE7i5rlOZgjbWKL97U W2CYw8CxgZVjFqFKcWlaUW6Rpa6CUVZaZnlOQmZuboGhqY6eWmFhcnpqfmJCYV6yXn525iBPq eAQh2MN7cGHCIUZKDSUmUV/0Ve6QQX1J+SmVGYnFGfFFpTmrxIUYZDg4lCd51VlyRQoJFqemp FWmZOcAghElLcPAoifC+BknzFhck5hZnpkOkTjEqSonzHgJJCIAkMkrz4NpggX+JUVZKmJcR6 BAhnoLUotzMElT5V4ziHIxKwrwCwDgS4snMK4Gb/gpoMRPQ4mZZDpDFJYkIKakGxsWJjCaz/+ 2x3mp+8GPZ08azE0p7Oa5zcTUJzJwV1fCoRXo/y6/djFK3V82JjunoUpnw5FtM054/G18zav+ w8d3KybDs5Q79wD9fTxxm2rtSoCD0eOw+FhvVWQ57Irdq1htsfSnQ+OOEpPmWSnaOOvcXW7dl rTyrOP1W1toI7r+diasqJrYqWiqxFGckGmoxFxUnAgCx7eIpdwIAAA== X-Env-Sender: boris.ostrovsky@oracle.com X-Msg-Ref: server-5.tower-21.messagelabs.com!1493842882!58578333!1 X-Originating-IP: [141.146.126.69] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogMTQxLjE0Ni4xMjYuNjkgPT4gMjc3MjE4\n X-StarScan-Received: X-StarScan-Version: 9.4.12; banners=-,-,- X-VirusChecked: Checked Received: (qmail 41227 invoked from network); 3 May 2017 20:21:23 -0000 Received: from aserp1040.oracle.com (HELO aserp1040.oracle.com) (141.146.126.69) by server-5.tower-21.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 3 May 2017 20:21:23 -0000 Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id v43KLL21019380 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 3 May 2017 20:21:21 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id v43KLKYE021974 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 3 May 2017 20:21:20 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id v43KLKkT011954; Wed, 3 May 2017 20:21:20 GMT Received: from dhcp-burlington7-2nd-B-east-10-152-55-162.usdhcp.oraclecorp.com.com (/10.152.52.138) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 03 May 2017 13:21:19 -0700 From: Boris Ostrovsky To: jgross@suse.com Date: Wed, 3 May 2017 16:20:51 -0400 Message-Id: <1493842851-10859-1-git-send-email-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 2.7.4 X-Source-IP: aserv0022.oracle.com [141.146.126.234] Cc: xen-devel@lists.xenproject.org, Boris Ostrovsky , linux-kernel@vger.kernel.org Subject: [Xen-devel] [PATCH] xen/x86: Do not call xen_init_time_ops() until shared_info is initialized X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Routines that are set by xen_init_time_ops() use shared_info's pvclock_vcpu_time_info area. This area is not properly available until shared_info is mapped in xen_setup_shared_info(). This became especially problematic due to commit dd759d93f4dd ("x86/timers: Add simple udelay calibration") where we end up reading tsc_to_system_mul from xen_dummy_shared_info (i.e. getting zero value) and then trying to divide by it in pvclock_tsc_khz(). Signed-off-by: Boris Ostrovsky Reviewed-by: Juergen Gross --- arch/x86/xen/enlighten_pv.c | 9 +++++++-- arch/x86/xen/time.c | 2 +- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index a732bc2..6f80a01 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -988,6 +988,13 @@ void xen_setup_shared_info(void) #endif xen_setup_mfn_list_list(); + + /* + * Now that shared info is set up we can start using routines that + * point to pvclock area. + */ + if (system_state == SYSTEM_BOOTING) + xen_init_time_ops(); } /* This is called once we have the cpu_possible_mask */ @@ -1286,8 +1293,6 @@ asmlinkage __visible void __init xen_start_kernel(void) x86_init.oem.arch_setup = xen_arch_setup; x86_init.oem.banner = xen_banner; - xen_init_time_ops(); - /* * Set up some pagetable state before starting to set any ptes. */ diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 090c7eb..a1895a8 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -406,7 +406,7 @@ static void __init xen_time_init(void) pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); } -void __init xen_init_time_ops(void) +void __ref xen_init_time_ops(void) { pv_time_ops = xen_time_ops;