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: 13425682 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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 AF430CDB474 for ; Tue, 17 Oct 2023 18:26:23 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.618329.961842 (Exim 4.92) (envelope-from ) id 1qsolc-0005Ff-SW; Tue, 17 Oct 2023 18:26:08 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 618329.961842; Tue, 17 Oct 2023 18:26:08 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsolc-0005FY-PP; Tue, 17 Oct 2023 18:26:08 +0000 Received: by outflank-mailman (input) for mailman id 618329; Tue, 17 Oct 2023 18:26:06 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsola-0005FN-T8 for xen-devel@lists.xenproject.org; Tue, 17 Oct 2023 18:26:06 +0000 Received: from casper.infradead.org (casper.infradead.org [2001:8b0:10b:1236::1]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id a048d7a8-6d1a-11ee-98d4-6d05b1d4d9a1; Tue, 17 Oct 2023 20:26:02 +0200 (CEST) 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 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list X-Inumbo-ID: a048d7a8-6d1a-11ee-98d4-6d05b1d4d9a1 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==; 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 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html 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); } }