From patchwork Fri Mar 18 17:01:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 8622601 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E195AC0553 for ; Fri, 18 Mar 2016 17:23:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0F9422039D for ; Fri, 18 Mar 2016 17:23:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 06BE220460 for ; Fri, 18 Mar 2016 17:23:22 +0000 (UTC) Received: from localhost ([::1]:45242 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agy7N-0008O1-Ac for patchwork-qemu-devel@patchwork.kernel.org; Fri, 18 Mar 2016 13:23:21 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41940) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agxmP-0006hw-2T for qemu-devel@nongnu.org; Fri, 18 Mar 2016 13:01:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1agxmK-00087O-2H for qemu-devel@nongnu.org; Fri, 18 Mar 2016 13:01:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55299) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agxmJ-000872-PD for qemu-devel@nongnu.org; Fri, 18 Mar 2016 13:01:35 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 5E537C05005E for ; Fri, 18 Mar 2016 17:01:35 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-34.ams2.redhat.com [10.36.116.34]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2IH1Wdc006627 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Fri, 18 Mar 2016 13:01:34 -0400 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id C1EDA3006AF3; Fri, 18 Mar 2016 18:01:28 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Fri, 18 Mar 2016 18:01:14 +0100 Message-Id: <1458320487-19603-28-git-send-email-armbru@redhat.com> In-Reply-To: <1458320487-19603-1-git-send-email-armbru@redhat.com> References: <1458320487-19603-1-git-send-email-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 27/40] ivshmem: Rely on server sending the ID right after the version X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The protocol specification (ivshmem-spec.txt, formerly ivshmem_device_spec.txt) has always required the ID message to be sent right at the beginning, and ivshmem-server has always complied. The device, however, accepts it out of order. If an interrupt setup arrived before it, though, it would be misinterpreted as connect notification. Fix the latent bug by relying on the spec and ivshmem-server's actual behavior. Signed-off-by: Markus Armbruster Reviewed-by: Marc-André Lureau Message-Id: <1458066895-20632-28-git-send-email-armbru@redhat.com> --- hw/misc/ivshmem.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 7f439c3..da32a74 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -653,8 +653,6 @@ static void process_msg(IVShmemState *s, int64_t msg, int fd, Error **errp) if (fd >= 0) { process_msg_connect(s, msg, fd, errp); - } else if (s->vm_id == -1) { - s->vm_id = msg; } else { process_msg_disconnect(s, msg, errp); } @@ -722,6 +720,30 @@ static void ivshmem_recv_setup(IVShmemState *s, Error **errp) } /* + * ivshmem-server sends the remaining initial messages in a fixed + * order, but the device has always accepted them in any order. + * Stay as compatible as practical, just in case people use + * servers that behave differently. + */ + + /* + * ivshmem_device_spec.txt has always required the ID message + * right here, and ivshmem-server has always complied. However, + * older versions of the device accepted it out of order, but + * broke when an interrupt setup message arrived before it. + */ + msg = ivshmem_recv_msg(s, &fd, &err); + if (err) { + error_propagate(errp, err); + return; + } + if (fd != -1 || msg < 0 || msg > IVSHMEM_MAX_PEERS) { + error_setg(errp, "server sent invalid ID message"); + return; + } + s->vm_id = msg; + + /* * Receive more messages until we got shared memory. */ do { @@ -956,7 +978,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) /* we allocate enough space for 16 peers and grow as needed */ resize_peers(s, 16); - s->vm_id = -1; pci_register_bar(dev, 2, attr, &s->bar);