From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67F52C5DF60 for ; Tue, 5 Nov 2019 21:50:49 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 29F622087E for ; Tue, 5 Nov 2019 21:50:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29F622087E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50662 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iS6it-0004os-Pz for qemu-devel@archiver.kernel.org; Tue, 05 Nov 2019 16:50:47 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59074) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iS5pj-0001Ud-Gb for qemu-devel@nongnu.org; Tue, 05 Nov 2019 15:53:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iS5pi-0002X1-92 for qemu-devel@nongnu.org; Tue, 05 Nov 2019 15:53:47 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:28960 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iS5pe-0002Bl-NJ; Tue, 05 Nov 2019 15:53:42 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xA5KpYSZ079132; Tue, 5 Nov 2019 15:53:21 -0500 Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0b-001b2d01.pphosted.com with ESMTP id 2w3dfhxm18-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 Nov 2019 15:53:21 -0500 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id xA5KnuOM005612; Tue, 5 Nov 2019 20:53:20 GMT Received: from b01cxnp23032.gho.pok.ibm.com (b01cxnp23032.gho.pok.ibm.com [9.57.198.27]) by ppma04wdc.us.ibm.com with ESMTP id 2w11e7985c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 Nov 2019 20:53:20 +0000 Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xA5KrKQx52166964 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 5 Nov 2019 20:53:20 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0C19512405E; Tue, 5 Nov 2019 20:53:20 +0000 (GMT) Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EDFA2124058; Tue, 5 Nov 2019 20:53:19 +0000 (GMT) Received: from localhost (unknown [9.53.179.218]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 5 Nov 2019 20:53:19 +0000 (GMT) From: Michael Roth To: qemu-devel@nongnu.org Subject: [PATCH 06/55] xen-bus: Fix backend state transition on device reset Date: Tue, 5 Nov 2019 14:51:54 -0600 Message-Id: <20191105205243.3766-7-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191105205243.3766-1-mdroth@linux.vnet.ibm.com> References: <20191105205243.3766-1-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-11-05_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911050170 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.158.5 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: Anthony PERARD , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Anthony PERARD When a frontend wants to reset its state and the backend one, it starts with setting "Closing", then waits for the backend (QEMU) to do the same. But when QEMU is setting "Closing" to its state, it triggers an event (xenstore watch) that re-execute xen_device_backend_changed() and set the backend state to "Closed". QEMU should wait for the frontend to set "Closed" before doing the same. Before setting "Closed" to the backend_state, we are also going to check if there is a frontend. If that the case, when the backend state is set to "Closing" the frontend should react and sets its state to "Closing" then "Closed". The backend should wait for that to happen. Fixes: b6af8926fb858c4f1426e5acb2cfc1f0580ec98a Signed-off-by: Anthony PERARD Reviewed-by: Paul Durrant Message-Id: <20190823101534.465-2-anthony.perard@citrix.com> (cherry picked from commit cb3231460747552d70af9d546dc53d8195bcb796) Signed-off-by: Michael Roth --- hw/xen/xen-bus.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 7503eea9e9..5929aa4b2e 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -516,6 +516,23 @@ static void xen_device_backend_set_online(XenDevice *xendev, bool online) xen_device_backend_printf(xendev, "online", "%u", online); } +/* + * Tell from the state whether the frontend is likely alive, + * i.e. it will react to a change of state of the backend. + */ +static bool xen_device_state_is_active(enum xenbus_state state) +{ + switch (state) { + case XenbusStateInitWait: + case XenbusStateInitialised: + case XenbusStateConnected: + case XenbusStateClosing: + return true; + default: + return false; + } +} + static void xen_device_backend_changed(void *opaque) { XenDevice *xendev = opaque; @@ -539,11 +556,11 @@ static void xen_device_backend_changed(void *opaque) /* * If the toolstack (or unplug request callback) has set the backend - * state to Closing, but there is no active frontend (i.e. the - * state is not Connected) then set the backend state to Closed. + * state to Closing, but there is no active frontend then set the + * backend state to Closed. */ if (xendev->backend_state == XenbusStateClosing && - xendev->frontend_state != XenbusStateConnected) { + !xen_device_state_is_active(state)) { xen_device_backend_set_state(xendev, XenbusStateClosed); } -- 2.17.1