From nobody Tue Feb 10 02:00:43 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 ARC-Seal: i=1; a=rsa-sha256; t=1602318456; cv=none; d=zohomail.com; s=zohoarc; b=AfyIJgeLoCSkgdnomJxiHURwtQNyVrFaDdUvqAQElgF/Cp8ArnbB52je7GDAthWUD7o/AJxV7RMM96mohld7r2b83ULl/Fx1j8fPMGOtmcN4ZQ37rCWPMYzeD+UsiWPoCpQR60xuewH2jdX8PzVCd/rWGHTHYyaw6FSB+/1uAwc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1602318456; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=ceM7PphOnMySWLEUgFCdxPQq6ixQ0Q1whnbjS30O+vg=; b=E0xYo2tnclJmr+9cxf2gXXdhgvj5JtWM4xTm0o0Mi1ySXaQ/2IpsSp9+Uhceu3DoC5Oif9RZMRrrHdOSGj0fXav1x6C/3Rr/VaxL9HIWGEBVF2RbFXzA7HTBzutDYI8WizNJzGjCHLEGMu+tExAnKmpRMmIfFQ3R1CiFC7+c1ZU= ARC-Authentication-Results: i=1; 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 header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1602318456380618.5677453251336; Sat, 10 Oct 2020 01:27:36 -0700 (PDT) Received: from localhost ([::1]:40952 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kRAE2-0003xa-Vb for importer@patchew.org; Sat, 10 Oct 2020 04:27:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41408) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kR9la-0004et-8H for qemu-devel@nongnu.org; Sat, 10 Oct 2020 03:58:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28769) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kR9lV-0006ld-BN for qemu-devel@nongnu.org; Sat, 10 Oct 2020 03:58:09 -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-397-vlVxek2SMI6MxKDqesFufw-1; Sat, 10 Oct 2020 03:58:00 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D45AF805F06; Sat, 10 Oct 2020 07:57:59 +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 71B2C1002C01; Sat, 10 Oct 2020 07:57:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602316684; 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=ceM7PphOnMySWLEUgFCdxPQq6ixQ0Q1whnbjS30O+vg=; b=J/aoIvpu4w96NHAf+l4lLtxk0ebwGZ3QuX7qHNqVs6l2pdTmvj/H7nR5gPk3wwT5GRbyEv au+YciAKFkk5Y9uj1TNUkSFRKr3lEaxtYYCD1p4LQU0L/qTrS1k8U4w3yOJJak/j1vi9KB o02XgZjlWj/Et58qASJix+m7JkM1d3Q= X-MC-Unique: vlVxek2SMI6MxKDqesFufw-1 From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 31/39] device_core: use drain_call_rcu in in qmp_device_add Date: Sat, 10 Oct 2020 03:57:31 -0400 Message-Id: <20201010075739.951385-32-pbonzini@redhat.com> In-Reply-To: <20201010075739.951385-1-pbonzini@redhat.com> References: <20201010075739.951385-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@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=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/10 02:57:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: , Cc: Stefan Hajnoczi , Stefan Hajnoczi , Maxim Levitsky Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" From: Maxim Levitsky Soon, a device removal might only happen on RCU callback execution. This is okay for device-del which provides a DEVICE_DELETED event, but not for the failure case of device-add. To avoid changing monitor semantics, just drain all pending RCU callbacks on error. Signed-off-by: Maxim Levitsky Suggested-by: Stefan Hajnoczi Reviewed-by: Stefan Hajnoczi Message-Id: <20200913160259.32145-4-mlevitsk@redhat.com> [Don't use it in qmp_device_del. - Paolo] Signed-off-by: Paolo Bonzini --- softmmu/qdev-monitor.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c index e9b7228480..bcfb90a08f 100644 --- a/softmmu/qdev-monitor.c +++ b/softmmu/qdev-monitor.c @@ -803,6 +803,18 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, = Error **errp) return; } dev =3D qdev_device_add(opts, errp); + + /* + * Drain all pending RCU callbacks. This is done because + * some bus related operations can delay a device removal + * (in this case this can happen if device is added and then + * removed due to a configuration error) + * to a RCU callback, but user might expect that this interface + * will finish its job completely once qmp command returns result + * to the user + */ + drain_call_rcu(); + if (!dev) { qemu_opts_del(opts); return; --=20 2.26.2