From nobody Mon Feb 9 12:09:36 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1631106830285722.2735733857099; Wed, 8 Sep 2021 06:13:50 -0700 (PDT) Received: from localhost ([::1]:35434 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mNxOf-0008WV-69 for importer@patchew.org; Wed, 08 Sep 2021 09:13:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52790) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNxLf-0002eW-GS for qemu-devel@nongnu.org; Wed, 08 Sep 2021 09:10:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:42459) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNxLX-0007j4-RW for qemu-devel@nongnu.org; Wed, 08 Sep 2021 09:10:43 -0400 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-267-PgdqMjuZPbuhoHgmIMGv6A-1; Wed, 08 Sep 2021 09:10:32 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7F4021006AA2; Wed, 8 Sep 2021 13:10:31 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 61C006B55B; Wed, 8 Sep 2021 13:10:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631106635; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TZamHiXO8rIULwZCUJLUmlWN9ZcqMHvojlRGZLLM6OA=; b=IfL6HDPDgRIVrHRRnupIVZLJerkj0BUi20Q2DXwqiHneu9IBtNNyDAki+5WUvgeIxZnMTw ZiD1jAxTa4aqoz6+N2SgGm/zEx67Q61tWmnu5kluUjZ4qWGmQ2dm77I1IMk7qCVDPpWpaa YMo+gOjXQXGrwgLAsWb6XTSr0bXeFj4= X-MC-Unique: PgdqMjuZPbuhoHgmIMGv6A-1 From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [RFC PATCH 1/4] main-loop.h: introduce qemu_in_main_thread() Date: Wed, 8 Sep 2021 09:10:18 -0400 Message-Id: <20210908131021.774533-2-eesposit@redhat.com> In-Reply-To: <20210908131021.774533-1-eesposit@redhat.com> References: <20210908131021.774533-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=216.205.24.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.393, 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: , Cc: Kevin Wolf , Fam Zheng , Vladimir Sementsov-Ogievskiy , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Eduardo Habkost , Juan Quintela , John Snow , Emanuele Giuseppe Esposito , Richard Henderson , "Dr. David Alan Gilbert" , qemu-devel@nongnu.org, Hanna Reitz , Stefan Hajnoczi , Paolo Bonzini , Eric Blake Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1631106831539100001 Content-Type: text/plain; charset="utf-8" When invoked from the main loop, this function is the same as qemu_mutex_iothread_locked, and returns true if the BQL is held. When invoked from iothreads or tests, it returns true only if the current AioContext is the Main Loop. This essentially just extends qemu_mutex_iothread_locked to work also in unit tests or other users like storage-daemon, that run in the Main Loop but end up using the implementation in stubs/iothread-lock.c. Using qemu_mutex_iothread_locked in unit tests defaults to false because they use the implementation in stubs/iothread-lock, making all assertions added in next patches fail despite the AioContext is still the main loop. Signed-off-by: Emanuele Giuseppe Esposito --- include/qemu/main-loop.h | 13 +++++++++++++ softmmu/cpus.c | 5 +++++ stubs/iothread-lock.c | 5 +++++ 3 files changed, 23 insertions(+) diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h index 8dbc6fcb89..c6547207f7 100644 --- a/include/qemu/main-loop.h +++ b/include/qemu/main-loop.h @@ -245,6 +245,19 @@ AioContext *iohandler_get_aio_context(void); */ bool qemu_mutex_iothread_locked(void); =20 +/** + * qemu_in_main_thread: Return true if the function runs with BQL + * or in the main loop AioContext. + * + * This function falls back to qemu_mutex_iothread_locked() if + * called from the main loop, otherwise it checks if the current + * AioContext is the main loop. This is useful to check that the BQL + * is held, and not make it return false when invoked by unit + * tests or other users like storage-daemon that end up using + * stubs/iothread-lock.c implementation. + */ +bool qemu_in_main_thread(void); + /** * qemu_mutex_lock_iothread: Lock the main loop mutex. * diff --git a/softmmu/cpus.c b/softmmu/cpus.c index 071085f840..3f61a3c31d 100644 --- a/softmmu/cpus.c +++ b/softmmu/cpus.c @@ -481,6 +481,11 @@ bool qemu_mutex_iothread_locked(void) return iothread_locked; } =20 +bool qemu_in_main_thread(void) +{ + return qemu_mutex_iothread_locked(); +} + /* * The BQL is taken from so many places that it is worth profiling the * callers directly, instead of funneling them all through a single functi= on. diff --git a/stubs/iothread-lock.c b/stubs/iothread-lock.c index 5b45b7fc8b..ff7386e42c 100644 --- a/stubs/iothread-lock.c +++ b/stubs/iothread-lock.c @@ -6,6 +6,11 @@ bool qemu_mutex_iothread_locked(void) return false; } =20 +bool qemu_in_main_thread(void) +{ + return qemu_get_current_aio_context() =3D=3D qemu_get_aio_context(); +} + void qemu_mutex_lock_iothread_impl(const char *file, int line) { } --=20 2.27.0