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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 47866C07E96 for ; Thu, 15 Jul 2021 13:34:50 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0835B61167 for ; Thu, 15 Jul 2021 13:34:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0835B61167 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57260 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m41Vp-0003mf-2k for qemu-devel@archiver.kernel.org; Thu, 15 Jul 2021 09:34:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43036) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m41TL-0000ad-4k for qemu-devel@nongnu.org; Thu, 15 Jul 2021 09:32:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:31534) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m41TJ-0008F0-91 for qemu-devel@nongnu.org; Thu, 15 Jul 2021 09:32:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626355932; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type; bh=n3GlTYNmJoyDR8WFc2J6QaEdaIOZ5W4hodzWgv6HC1o=; b=SweXoDbp2E9rkeMAH/qYvZVpc8OiDK86AkKJschZ/R2/Kb0RPGcKKiBwIosB/7DhxGSy8+ 0NOsvvQ1IN2EDpsU6IgYmMz+6WzUGpA4tgOm5CoDnDHEs6Ql/rdw6CRIjx6HYMVXSvXCP/ BpH1/tHQ5xwht2nIoOcAf3fSFGv8rQs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-95-hHWoyilfNpWv3Gxj0YHuDA-1; Thu, 15 Jul 2021 09:32:09 -0400 X-MC-Unique: hHWoyilfNpWv3Gxj0YHuDA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 35C62800D62; Thu, 15 Jul 2021 13:32:08 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-81.ams2.redhat.com [10.36.112.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E00D869CB7; Thu, 15 Jul 2021 13:32:07 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 68296113865F; Thu, 15 Jul 2021 15:32:06 +0200 (CEST) From: Markus Armbruster To: Aravinda Prasad , Ganesh Goudar , David Gibson , qemu-devel@nongnu.org Subject: spapr_events: Sure we may ignore migrate_add_blocker() failure? Date: Thu, 15 Jul 2021 15:32:06 +0200 Message-ID: <87tukvaejt.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.698, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Commit 2500fb423a "migration: Include migration support for machine check handling" adds this: ret = migrate_add_blocker(spapr->fwnmi_migration_blocker, &local_err); if (ret == -EBUSY) { /* * We don't want to abort so we let the migration to continue. * In a rare case, the machine check handler will run on the target. * Though this is not preferable, it is better than aborting * the migration or killing the VM. */ warn_report("Received a fwnmi while migration was in progress"); } migrate_add_blocker() can fail in two ways: 1. -EBUSY: migration is already in progress Ignoring this one is clearly intentional. The comment explains why. I'm taking it at face value (I'm a spapr ignoramus). Aside: I doubt the warning is going to help users. 2. -EACCES: we're running with -only-migratable Why may we ignore -only-migratable here? By the way, we leak @local_err on failure. I'll post a patch, but I'd like my question answered first.