From patchwork Mon Feb 29 18:40:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 590107 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id D37E1140324 for ; Tue, 1 Mar 2016 05:53:39 +1100 (AEDT) Received: from localhost ([::1]:38487 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aaSws-0007RJ-1A for incoming@patchwork.ozlabs.org; Mon, 29 Feb 2016 13:53:38 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59736) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aaSki-00022Q-Fp for qemu-devel@nongnu.org; Mon, 29 Feb 2016 13:41:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aaSkh-0007qy-0r for qemu-devel@nongnu.org; Mon, 29 Feb 2016 13:41:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53698) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aaSkg-0007qF-Q3 for qemu-devel@nongnu.org; Mon, 29 Feb 2016 13:41:02 -0500 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 67ECEC0B78A2; Mon, 29 Feb 2016 18:41:02 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-22.ams2.redhat.com [10.36.116.22]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u1TIf0Ti006574 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 29 Feb 2016 13:41:01 -0500 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id ACAF530052F1; Mon, 29 Feb 2016 19:40:55 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Mon, 29 Feb 2016 19:40:41 +0100 Message-Id: <1456771254-17511-26-git-send-email-armbru@redhat.com> In-Reply-To: <1456771254-17511-1-git-send-email-armbru@redhat.com> References: <1456771254-17511-1-git-send-email-armbru@redhat.com> 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 Cc: claudio.fontana@huawei.com, cam@cs.ualberta.ca, mlureau@redhat.com, david.marchand@6wind.com, pbonzini@redhat.com Subject: [Qemu-devel] [PATCH 25/38] 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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 --- 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 831da53..8f976ca 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); } @@ -723,6 +721,30 @@ 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 { @@ -953,7 +975,6 @@ 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);