From patchwork Fri Jan 21 17:05:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1582672 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=XYbaWjPW; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4JgQxZ3Zw5z9t2p for ; Sat, 22 Jan 2022 04:15:28 +1100 (AEDT) Received: from localhost ([::1]:40990 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nAxUz-0008Ex-LF for incoming@patchwork.ozlabs.org; Fri, 21 Jan 2022 12:14:53 -0500 Received: from eggs.gnu.org ([209.51.188.92]:39748) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nAxMc-0007Fk-EG for qemu-devel@nongnu.org; Fri, 21 Jan 2022 12:06:14 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:55612) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nAxMW-0007iW-7X for qemu-devel@nongnu.org; Fri, 21 Jan 2022 12:06:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1642784767; 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=0lKET/CHADYOxeK1L9ugGUmIiq6t005bX20fB6EPZDQ=; b=XYbaWjPW1oWIr7CqvqQktrXLWrwYGH8zx+FkREsL+8AQxTb1ymLj73BqQDVxU1lB02vOag Q2YVqAQes/kVbgo7wPidrexEHCVWsx4s27GRmZp1Ah6Y/gGI5cEliTGQtkuIA++gZQPdTt kRBCgZgn3r+bY6Nw8hlimZEjnHCA3tM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-641-1jE_0TpoO8G7Nmq52N0gaw-1; Fri, 21 Jan 2022 12:06:04 -0500 X-MC-Unique: 1jE_0TpoO8G7Nmq52N0gaw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AC43C64083; Fri, 21 Jan 2022 17:06:00 +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 EE31E7EBCA; Fri, 21 Jan 2022 17:05:58 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v6 01/33] main-loop.h: introduce qemu_in_main_thread() Date: Fri, 21 Jan 2022 12:05:12 -0500 Message-Id: <20220121170544.2049944-2-eesposit@redhat.com> In-Reply-To: <20220121170544.2049944-1-eesposit@redhat.com> References: <20220121170544.2049944-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eesposit@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=-0.699, 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_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , qemu-devel@nongnu.org, "Denis V. Lunev" , Eric Blake , Emanuele Giuseppe Esposito , Juan Quintela , Daniel Henrique Barboza , Markus Armbruster , Eduardo Habkost , Richard Henderson , Greg Kurz , "Dr. David Alan Gilbert" , =?utf-8?q?C=C3=A9dric_Le_Go?= =?utf-8?q?ater?= , Stefan Hajnoczi , John Snow , David Gibson , Kevin Wolf , Vladimir Sementsov-Ogievskiy , =?utf-8?q?Daniel_P?= =?utf-8?q?=2E_Berrang=C3=A9?= , =?utf-8?q?Philippe_Mat?= =?utf-8?q?hieu-Daud=C3=A9?= , Hanna Reitz , qemu-ppc@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 Reviewed-by: Stefan Hajnoczi --- 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..6b8fa57c5d 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); +/** + * qemu_in_main_thread: same as qemu_mutex_iothread_locked when + * softmmu/cpus.c implementation is linked. Otherwise this function + * checks that the current AioContext is the global AioContext + * (main loop). + * + * This is useful when checking that the BQL is held, to avoid + * returning 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 23bca46b07..fd4e139289 100644 --- a/softmmu/cpus.c +++ b/softmmu/cpus.c @@ -485,6 +485,11 @@ bool qemu_mutex_iothread_locked(void) return iothread_locked; } +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 function. 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; } +bool qemu_in_main_thread(void) +{ + return qemu_get_current_aio_context() == qemu_get_aio_context(); +} + void qemu_mutex_lock_iothread_impl(const char *file, int line) { }