From patchwork Thu Nov 5 17:09:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 7562881 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4F4DFBEEA4 for ; Thu, 5 Nov 2015 17:13:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 89B6320812 for ; Thu, 5 Nov 2015 17:13:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 93ABD2080D for ; Thu, 5 Nov 2015 17:13:26 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZuO3o-0001zZ-FQ; Thu, 05 Nov 2015 17:10:52 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZuO3Q-00013K-TT for linux-arm-kernel@lists.infradead.org; Thu, 05 Nov 2015 17:10:30 +0000 X-IronPort-AV: E=Sophos;i="5.20,248,1444694400"; d="scan'208";a="310622009" From: Stefano Stabellini To: Subject: [PATCH 3/3] xen/arm: set the system time in Xen via the XENPF_settime hypercall Date: Thu, 5 Nov 2015 17:09:45 +0000 Message-ID: <1446743385-12848-3-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-DLP: MIA1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151105_091029_290079_C08079DB X-CRM114-Status: GOOD ( 14.26 ) X-Spam-Score: -6.9 (------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ian Campbell , linux-arm-kernel@lists.infradead.org, Stefano Stabellini Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If Linux is running as dom0, call XENPF_settime to update the system time in Xen on pvclock_gtod notifications. Signed-off-by: Stefano Stabellini Signed-off-by: Ian Campbell --- arch/arm/xen/enlighten.c | 52 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index b6aea9c..0176db0 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -123,6 +124,50 @@ static void xen_read_wallclock(struct timespec *ts) set_normalized_timespec(ts, now.tv_sec, now.tv_nsec); } +static int xen_pvclock_gtod_notify(struct notifier_block *nb, + unsigned long was_set, void *priv) +{ + /* Protected by the calling core code serialization */ + static struct timespec next_sync; + + struct xen_platform_op op; + struct timespec now; + + now = __current_kernel_time(); + + /* + * We only take the expensive HV call when the clock was set + * or when the 11 minutes RTC synchronization time elapsed. + */ + if (!was_set && timespec_compare(&now, &next_sync) < 0) + return NOTIFY_OK; + + op.interface_version = XENPF_INTERFACE_VERSION; + op.cmd = XENPF_settime; + op.u.settime.secs = now.tv_sec; + op.u.settime.nsecs = now.tv_nsec; + op.u.settime.system_time = arch_timer_read_counter(); + printk("GTOD: Setting to %ld.%ld at %lld\n", + (long)op.u.settime.secs, + (long)op.u.settime.nsecs, + (long long)op.u.settime.system_time); + (void)HYPERVISOR_dom0_op(&op); + + /* + * Move the next drift compensation time 11 minutes + * ahead. That's emulating the sync_cmos_clock() update for + * the hardware RTC. + */ + next_sync = now; + next_sync.tv_sec += 11 * 60; + + return NOTIFY_OK; +} + +static struct notifier_block xen_pvclock_gtod_notifier = { + .notifier_call = xen_pvclock_gtod_notify, +}; + static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; @@ -321,7 +366,12 @@ static int __init xen_guest_init(void) pv_time_ops.steal_clock = xen_stolen_accounting; static_key_slow_inc(¶virt_steal_enabled); xen_read_wallclock(&ts); - do_settimeofday(&ts); + if (xen_initial_domain()) + pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); + else { + xen_read_wallclock(&ts); + do_settimeofday(&ts); + } return 0; }