From nobody Tue May 13 04:35:14 2025 Delivered-To: importer2@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+importer2=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1673656842821545.5241076300952; Fri, 13 Jan 2023 16:40:42 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pGUa6-0004iy-HG; Fri, 13 Jan 2023 19:39:35 -0500 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 1pGUa0-0004gv-DF for qemu-devel@nongnu.org; Fri, 13 Jan 2023 19:39:28 -0500 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pGUZy-0005NN-EC for qemu-devel@nongnu.org; Fri, 13 Jan 2023 19:39:28 -0500 Received: from i7.infradead.org ([2001:8b0:10b:1:21e:67ff:fecb:7a92]) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pGUZf-004X3u-2C; Sat, 14 Jan 2023 00:39:10 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGUZk-001C2O-Up; Sat, 14 Jan 2023 00:39:12 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=0BzRiPtT6Te/hfyx5tNsli16NvieteYxvnY7I5GXBoo=; b=GzhQbxnyhJiYcaVfOJ8utxNMPj x5ISbUeNB3Hd/qjf8102Z/e2QObt/0qPNoo6BAg+Sj+YP2FhS4pcQd/qd7SXM1xIjO3J/bUQxbQFb CYRZIGUwbOQIieXuwqQvDIsYPa/S3BKPpCdsEhPGyGwH/4POC0z4dCNWsz4TvuXrRHSgfsBvVlcKy nLE/URkJR5Fp0CyPkJZFMO5KTjUfBlQXYA6BBdHf9fr1CWi86SbGfqYyAYDADYYjlSJX0Jd/HeQ++ tI6E0jdz/ZQz/Dnhivxu2YqJbje5BgfZ4XvrJ71u3fcIhzEwbe1N5ArKp9oYvGo5SV79yvK5h2If3 Pmm26gIQ==; From: David Woodhouse To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Paul Durrant , Joao Martins , Ankur Arora , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Thomas Huth , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Juan Quintela , "Dr . David Alan Gilbert" , Claudio Fontana , Julien Grall , "Michael S. Tsirkin" , arcel Apfelbaum Subject: [RFC PATCH 4/5] hw/xen: [FIXME] Avoid deadlock in xen_evtchn_set_gsi() Date: Sat, 14 Jan 2023 00:39:08 +0000 Message-Id: <20230114003909.284331-5-dwmw2@infradead.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230114003909.284331-1-dwmw2@infradead.org> References: <20230114003909.284331-1-dwmw2@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html 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+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=2001:8b0:10b:1:d65d:64ff:fe57:4e05; envelope-from=BATV+3a1a5416dcf0d1877a74+7083+infradead.org+dwmw2@desiato.srs.infradead.org; helo=desiato.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+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1673656843602100001 Content-Type: text/plain; charset="utf-8" From: David Woodhouse Signed-off-by: David Woodhouse --- hw/i386/kvm/xen_evtchn.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c index 18c88229ab..c4103ee98b 100644 --- a/hw/i386/kvm/xen_evtchn.c +++ b/hw/i386/kvm/xen_evtchn.c @@ -1436,6 +1436,14 @@ bool xen_evtchn_set_gsi(int gsi, int level) return false; } =20 + /* + * XXX: We access this without locking. Because we'd deadlock + * if it was the callback_gsi. Do something cleverer. + */ + if (gsi && gsi =3D=3D s->callback_gsi) { + return false; + } + QEMU_LOCK_GUARD(&s->port_lock); =20 pirq =3D s->gsi_pirq[gsi]; --=20 2.35.3