From patchwork Tue Oct 17 18:25:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 1850353 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=u2pl0HXy; dkim-atps=neutral Authentication-Results: legolas.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=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4S92WW24Zqz20Pd for ; Wed, 18 Oct 2023 05:27:03 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qsoln-0006H6-Qo; Tue, 17 Oct 2023 14:26:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qsolV-0006F2-3j for qemu-devel@nongnu.org; Tue, 17 Oct 2023 14:26:05 -0400 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qsolQ-0001UD-H8 for qemu-devel@nongnu.org; Tue, 17 Oct 2023 14:25:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description; bh=mT1XScI7NSJ4weZ5c1NJoTEjfaqAFFggM/PoQY19qlQ=; b=u2pl0HXyBSCIO8jw1OQWFNhf2O Hj/MN1k4AK95NViqo7qIk/mSIRKYon9a3ezB59j4K+iKbmyMri//ejsICoyYSix0lyRkGFkcyL8Ou vMliReAQ0IrMARgiZES6WA1xMB9twTeVfZaMrm7HvisUfl1T8yHWWDxG1ReTokk08H8//LXKNOliM dUxj2P1UJ++Q69tUfpC1Q86upQsLUc8mxFbFAnIxev/h+kAeEKtWt0+X7iWYdUwPCLGF3kdmr5wMK 7jQS8z9M1Mx5BxrobTWp3WEr1ZawgXQ8MGh4TnVlvCyk5ih0AL87cVI0NjBGyW7h/y/UBLoyHHEI6 10GUyejw==; Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qsolL-00DrCq-Pk; Tue, 17 Oct 2023 18:25:51 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qsolI-000Par-2F; Tue, 17 Oct 2023 19:25:48 +0100 From: David Woodhouse To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Marcel Apfelbaum , Paolo Bonzini , Richard Henderson , Eduardo Habkost , Stefano Stabellini , Anthony Perard , Paul Durrant , Jason Wang , xen-devel@lists.xenproject.org Subject: [PATCH 3/4] [WTF] avoid qemu_del_nic() in xen_netdev_unrealize() on shutdown Date: Tue, 17 Oct 2023 19:25:44 +0100 Message-Id: <20231017182545.97973-4-dwmw2@infradead.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231017182545.97973-1-dwmw2@infradead.org> References: <20231017182545.97973-1-dwmw2@infradead.org> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Received-SPF: none client-ip=2001:8b0:10b:1236::1; envelope-from=BATV+e442e50539a6073fd887+7359+infradead.org+dwmw2@casper.srs.infradead.org; helo=casper.infradead.org X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham 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: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: David Woodhouse When QEMU is exiting, qemu_cleanup() calls net_cleanup(), which deletes the NIC from underneath the xen-net-device. When xen_netdev_unrealize() is later called via the xenbus exit notifier, it crashes. Signed-off-by: David Woodhouse --- hw/net/xen_nic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c index 84914c329c..8d25fb3101 100644 --- a/hw/net/xen_nic.c +++ b/hw/net/xen_nic.c @@ -25,6 +25,8 @@ #include "qapi/qmp/qdict.h" #include "qapi/error.h" +#include "sysemu/runstate.h" + #include #include #include @@ -530,7 +532,11 @@ static void xen_netdev_unrealize(XenDevice *xendev) /* Disconnect from the frontend in case this has not already happened */ xen_netdev_disconnect(xendev, NULL); - if (netdev->nic) { + /* + * WTF? In RUN_STATE_SHUTDOWN, qemu_cleanup()→net_cleanup() already deleted + * our NIC from underneath us! + */ + if (netdev->nic && !runstate_check(RUN_STATE_SHUTDOWN)) { qemu_del_nic(netdev->nic); } }