From patchwork Wed Mar 2 18:03:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergio Lopez X-Patchwork-Id: 12766527 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 4AAEDC433EF for ; Wed, 2 Mar 2022 18:16:34 +0000 (UTC) Received: from localhost ([::1]:52118 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nPTWb-0005aR-9H for qemu-devel@archiver.kernel.org; Wed, 02 Mar 2022 13:16:33 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57996) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nPTLb-0001D5-GU for qemu-devel@nongnu.org; Wed, 02 Mar 2022 13:05:11 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:52769) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nPTLZ-0006st-Lh for qemu-devel@nongnu.org; Wed, 02 Mar 2022 13:05:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646244308; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KdMdqEWeBP2boGVGfeEr3E5hnozpl+T46v4UlfqVOqc=; b=VuHJRyZrKM5x6wbkCR8i5+xlKd0c3IUtZzA4pP4iGg6sOP3pbfUXsMYGCEJG7JGS8PndH7 mgW9dd2ILMekoc3ZSzLZTHOOXXt9wGTDA4QJJ1vGj0ZrVTL+3h+zET12654DSDRFFeMT6e jutIEbYRT4m2ROSCn2lxQhSYcQhs36U= 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-385-p_rODWPJMeeITqszFUTRsg-1; Wed, 02 Mar 2022 13:05:05 -0500 X-MC-Unique: p_rODWPJMeeITqszFUTRsg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EA3CF1006AA6; Wed, 2 Mar 2022 18:05:02 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.33.36.14]) by smtp.corp.redhat.com (Postfix) with ESMTP id 754BB838D1; Wed, 2 Mar 2022 18:04:13 +0000 (UTC) From: Sergio Lopez To: qemu-devel@nongnu.org Subject: [PATCH v2 1/3] event_notifier: add event_notifier_get_wfd() Date: Wed, 2 Mar 2022 19:03:16 +0100 Message-Id: <20220302180318.28893-2-slp@redhat.com> In-Reply-To: <20220302180318.28893-1-slp@redhat.com> References: <20220302180318.28893-1-slp@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Received-SPF: pass client-ip=170.10.129.124; envelope-from=slp@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: Elena Ufimtseva , John G Johnson , kvm@vger.kernel.org, David Hildenbrand , Eric Farman , Alex Williamson , Matthew Rosato , qemu-block@nongnu.org, "Michael S. Tsirkin" , Halil Pasic , Christian Borntraeger , vgoyal@redhat.com, Thomas Huth , Sergio Lopez , Richard Henderson , qemu-s390x@nongnu.org, Stefan Hajnoczi , Jagannathan Raman , Kevin Wolf , Cornelia Huck , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Hanna Reitz , Paolo Bonzini , Fam Zheng Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" event_notifier_get_fd(const EventNotifier *e) always returns EventNotifier's read file descriptor (rfd). This is not a problem when the EventNotifier is backed by a an eventfd, as a single file descriptor is used both for reading and triggering events (rfd == wfd). But, when EventNotifier is backed by a pipe pair, we have two file descriptors, one that can only be used for reads (rfd), and the other only for writes (wfd). There's, at least, one known situation in which we need to obtain wfd instead of rfd, which is when setting up the file that's going to be sent to the peer in vhost's SET_VRING_CALL. Add a new event_notifier_get_wfd(const EventNotifier *e) that can be used to obtain wfd where needed. Signed-off-by: Sergio Lopez --- include/qemu/event_notifier.h | 1 + util/event_notifier-posix.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/qemu/event_notifier.h b/include/qemu/event_notifier.h index b79add035d..8a4ff308e1 100644 --- a/include/qemu/event_notifier.h +++ b/include/qemu/event_notifier.h @@ -38,6 +38,7 @@ int event_notifier_test_and_clear(EventNotifier *); #ifdef CONFIG_POSIX void event_notifier_init_fd(EventNotifier *, int fd); int event_notifier_get_fd(const EventNotifier *); +int event_notifier_get_wfd(const EventNotifier *); #else HANDLE event_notifier_get_handle(EventNotifier *); #endif diff --git a/util/event_notifier-posix.c b/util/event_notifier-posix.c index 8307013c5d..16294e98d4 100644 --- a/util/event_notifier-posix.c +++ b/util/event_notifier-posix.c @@ -99,6 +99,11 @@ int event_notifier_get_fd(const EventNotifier *e) return e->rfd; } +int event_notifier_get_wfd(const EventNotifier *e) +{ + return e->wfd; +} + int event_notifier_set(EventNotifier *e) { static const uint64_t value = 1;