From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B916C282C7 for ; Tue, 29 Jan 2019 11:50:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C350214DA for ; Tue, 29 Jan 2019 11:50:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548762618; bh=5m8rru/IuJE55SNaktCJrTxHg5v8a0N10lzNA4VPhwI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=viLUekeBxid/ooBnmeRULLTHZluMJyLAJ8vs9EvcI6+CefWdxyo6wcKMhnFwtWlxY a/LwneQ4GnvSwjtWdB+nd4tmbmxUsxq2QVwOq/umlIxiLYgzcHzuJWN1f27j2/EO1i 0FsVvgess1XgsM3htN2fwIkxfdhydu839BMC7PmM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731639AbfA2LuQ (ORCPT ); Tue, 29 Jan 2019 06:50:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:41452 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731618AbfA2LuN (ORCPT ); Tue, 29 Jan 2019 06:50:13 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 407E52177E; Tue, 29 Jan 2019 11:50:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548762612; bh=5m8rru/IuJE55SNaktCJrTxHg5v8a0N10lzNA4VPhwI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZM8XVl2dyKt9SWYwSdcNrbF6jLKjc+0iSb6dXmqgS5c64DzGzNJFRcRkbKjt+GYys ADBG9gOPM9N1BvGgMeXTfwh3ADhLPWhAVC9o4q9KI0xByLHnmpAARI2cyyCiLjEY3H cOjjKovc1ufy5o19U1VDqWWjPHnE797T9Vj7wsOo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hans van Kranenburg , Juergen Gross , Boris Ostrovsky Subject: [PATCH 4.14 65/68] xen: Fix x86 sched_clock() interface for xen Date: Tue, 29 Jan 2019 12:36:27 +0100 Message-Id: <20190129113138.034020219@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190129113131.751891514@linuxfoundation.org> References: <20190129113131.751891514@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross commit 867cefb4cb1012f42cada1c7d1f35ac8dd276071 upstream. Commit f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") broke Xen guest time handling across migration: [ 187.249951] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 187.251137] OOM killer disabled. [ 187.251137] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 187.252299] suspending xenstore... [ 187.266987] xen:grant_table: Grant tables using version 1 layout [18446743811.706476] OOM killer enabled. [18446743811.706478] Restarting tasks ... done. [18446743811.720505] Setting capacity to 16777216 Fix that by setting xen_sched_clock_offset at resume time to ensure a monotonic clock value. [boris: replaced pr_info() with pr_info_once() in xen_callback_vector() to avoid printing with incorrect timestamp during resume (as we haven't re-adjusted the clock yet)] Fixes: f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") Cc: # 4.11 Reported-by: Hans van Kranenburg Signed-off-by: Juergen Gross Tested-by: Hans van Kranenburg Signed-off-by: Boris Ostrovsky Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- arch/x86/xen/time.c | 12 +++++++++--- drivers/xen/events/events_base.c | 2 +- 2 files changed, 10 insertions(+), 4 deletions(-) --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -361,8 +361,6 @@ void xen_timer_resume(void) { int cpu; - pvclock_resume(); - if (xen_clockevent != &xen_vcpuop_clockevent) return; @@ -379,12 +377,15 @@ static const struct pv_time_ops xen_time }; static struct pvclock_vsyscall_time_info *xen_clock __read_mostly; +static u64 xen_clock_value_saved; void xen_save_time_memory_area(void) { struct vcpu_register_time_memory_area t; int ret; + xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset; + if (!xen_clock) return; @@ -404,7 +405,7 @@ void xen_restore_time_memory_area(void) int ret; if (!xen_clock) - return; + goto out; t.addr.v = &xen_clock->pvti; @@ -421,6 +422,11 @@ void xen_restore_time_memory_area(void) if (ret != 0) pr_notice("Cannot restore secondary vcpu_time_info (err %d)", ret); + +out: + /* Need pvclock_resume() before using xen_clocksource_read(). */ + pvclock_resume(); + xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved; } static void xen_setup_vsyscall_time_info(void) --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1650,7 +1650,7 @@ void xen_callback_vector(void) xen_have_vector_callback = 0; return; } - pr_info("Xen HVM callback vector for event delivery is enabled\n"); + pr_info_once("Xen HVM callback vector for event delivery is enabled\n"); alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, xen_hvm_callback_vector); }