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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 95260C35242 for ; Fri, 14 Feb 2020 23:22:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 486FD2081E for ; Fri, 14 Feb 2020 23:22:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="kb7E8/9P" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 486FD2081E Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EEAF56B0005; Fri, 14 Feb 2020 18:22:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E9E8E6B0006; Fri, 14 Feb 2020 18:22:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D144C6B0007; Fri, 14 Feb 2020 18:22:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0023.hostedemail.com [216.40.44.23]) by kanga.kvack.org (Postfix) with ESMTP id B16AB6B0005 for ; Fri, 14 Feb 2020 18:22:38 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 559F5181AC9C6 for ; Fri, 14 Feb 2020 23:22:38 +0000 (UTC) X-FDA: 76490309196.24.spoon96_51273eb1e8d01 X-HE-Tag: spoon96_51273eb1e8d01 X-Filterd-Recvd-Size: 7977 Received: from smtp-fw-9101.amazon.com (smtp-fw-9101.amazon.com [207.171.184.25]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Fri, 14 Feb 2020 23:22:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581722558; x=1613258558; h=date:from:to:subject:message-id:references:mime-version: in-reply-to; bh=eMxbySX2+Q9C9EOEiRSgj0VbC617wxOCoVYvUYL8fpI=; b=kb7E8/9Phov07pkUi5u89J7geqTV3uERWKfrdETiGMoSwvQWsviK0MYy A8vOByKhtJiG4F7rwHSh+OjCAU1UhGOOviAWv3Es3y54fQ/9mo7UXlS3B WU/eMxh+CDAw5WzcPedRoBQ5rw6rliFhySlw2BPCQvtlHV28rwRSWx2AE k=; IronPort-SDR: y8XMJpVBLvSO59b36Gvrm5SW1/nIbpAtTjjiO/1OKPsLUicx920bBL8XverR7HeoI3BJ2aceF9 AUi0ra0Y0/HQ== X-IronPort-AV: E=Sophos;i="5.70,442,1574121600"; d="scan'208";a="16797643" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1d-f273de60.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 14 Feb 2020 23:22:34 +0000 Received: from EX13MTAUEE002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-f273de60.us-east-1.amazon.com (Postfix) with ESMTPS id 1A7F0A07D0; Fri, 14 Feb 2020 23:22:26 +0000 (UTC) Received: from EX13D08UEE003.ant.amazon.com (10.43.62.118) by EX13MTAUEE002.ant.amazon.com (10.43.62.24) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Fri, 14 Feb 2020 23:22:09 +0000 Received: from EX13MTAUEA001.ant.amazon.com (10.43.61.82) by EX13D08UEE003.ant.amazon.com (10.43.62.118) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Fri, 14 Feb 2020 23:22:08 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.61.243) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Fri, 14 Feb 2020 23:22:08 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 756394028E; Fri, 14 Feb 2020 23:22:08 +0000 (UTC) Date: Fri, 14 Feb 2020 23:22:08 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 01/12] xen/manage: keep track of the on-going suspend mode Message-ID: <36567b7204db25d7307a165a6565837a213efdf8.1581721799.git.anchalag@amazon.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Munehisa Kamata Guest hibernation is different from xen suspend/resume/live migration. Xen save/restore does not use pm_ops as is needed by guest hibernation. Hibernation in guest follows ACPI path and is guest inititated , the hibernation image is saved within guest as compared to later modes which are xen toolstack assisted and image creation/storage is in control of hypervisor/host machine. To differentiate between Xen suspend and PM hibernation, keep track of the on-going suspend mode by mainly using a new PM notifier. Introduce simple functions which help to know the on-going suspend mode so that other Xen-related code can behave differently according to the current suspend mode. Since Xen suspend doesn't have corresponding PM event, its main logic is modfied to acquire pm_mutex and set the current mode. Though, acquirng pm_mutex is still right thing to do, we may see deadlock if PM hibernation is interrupted by Xen suspend. PM hibernation depends on xenwatch thread to process xenbus state transactions, but the thread will sleep to wait pm_mutex which is already held by PM hibernation context in the scenario. Xen shutdown code may need some changes to avoid the issue. [Anchal Changelog: Merged patch xen/manage: introduce helper function to know the on-going suspend mode into this one for better readability] Signed-off-by: Anchal Agarwal Signed-off-by: Munehisa Kamata --- drivers/xen/manage.c | 73 +++++++++++++++++++++++++++++++++++++++++++ include/xen/xen-ops.h | 3 ++ 2 files changed, 76 insertions(+) diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index cd046684e0d1..0b30ab522b77 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -40,6 +41,31 @@ enum shutdown_state { /* Ignore multiple shutdown requests. */ static enum shutdown_state shutting_down = SHUTDOWN_INVALID; +enum suspend_modes { + NO_SUSPEND = 0, + XEN_SUSPEND, + PM_SUSPEND, + PM_HIBERNATION, +}; + +/* Protected by pm_mutex */ +static enum suspend_modes suspend_mode = NO_SUSPEND; + +bool xen_suspend_mode_is_xen_suspend(void) +{ + return suspend_mode == XEN_SUSPEND; +} + +bool xen_suspend_mode_is_pm_suspend(void) +{ + return suspend_mode == PM_SUSPEND; +} + +bool xen_suspend_mode_is_pm_hibernation(void) +{ + return suspend_mode == PM_HIBERNATION; +} + struct suspend_info { int cancelled; }; @@ -99,6 +125,10 @@ static void do_suspend(void) int err; struct suspend_info si; + lock_system_sleep(); + + suspend_mode = XEN_SUSPEND; + shutting_down = SHUTDOWN_SUSPEND; err = freeze_processes(); @@ -162,6 +192,10 @@ static void do_suspend(void) thaw_processes(); out: shutting_down = SHUTDOWN_INVALID; + + suspend_mode = NO_SUSPEND; + + unlock_system_sleep(); } #endif /* CONFIG_HIBERNATE_CALLBACKS */ @@ -387,3 +421,42 @@ int xen_setup_shutdown_event(void) EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); subsys_initcall(xen_setup_shutdown_event); + +static int xen_pm_notifier(struct notifier_block *notifier, + unsigned long pm_event, void *unused) +{ + switch (pm_event) { + case PM_SUSPEND_PREPARE: + suspend_mode = PM_SUSPEND; + break; + case PM_HIBERNATION_PREPARE: + case PM_RESTORE_PREPARE: + suspend_mode = PM_HIBERNATION; + break; + case PM_POST_SUSPEND: + case PM_POST_RESTORE: + case PM_POST_HIBERNATION: + /* Set back to the default */ + suspend_mode = NO_SUSPEND; + break; + default: + pr_warn("Receive unknown PM event 0x%lx\n", pm_event); + return -EINVAL; + } + + return 0; +}; + +static struct notifier_block xen_pm_notifier_block = { + .notifier_call = xen_pm_notifier +}; + +static int xen_setup_pm_notifier(void) +{ + if (!xen_hvm_domain()) + return -ENODEV; + + return register_pm_notifier(&xen_pm_notifier_block); +} + +subsys_initcall(xen_setup_pm_notifier); diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index d89969aa9942..6c36e161dfd1 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -40,6 +40,9 @@ u64 xen_steal_clock(int cpu); int xen_setup_shutdown_event(void); +bool xen_suspend_mode_is_xen_suspend(void); +bool xen_suspend_mode_is_pm_suspend(void); +bool xen_suspend_mode_is_pm_hibernation(void); extern unsigned long *xen_contiguous_bitmap; #if defined(CONFIG_XEN_PV) || defined(CONFIG_ARM) || defined(CONFIG_ARM64) -- 2.24.1.AMZN