From patchwork Mon Sep 8 09:17:50 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Marchand X-Patchwork-Id: 386836 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 5A0E614012C for ; Mon, 8 Sep 2014 19:18:54 +1000 (EST) Received: from localhost ([::1]:41820 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQv64-000386-7O for incoming@patchwork.ozlabs.org; Mon, 08 Sep 2014 05:18:52 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49002) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQv5O-00024E-Al for qemu-devel@nongnu.org; Mon, 08 Sep 2014 05:18:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XQv5I-0004vX-Mn for qemu-devel@nongnu.org; Mon, 08 Sep 2014 05:18:10 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:35966) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQv5I-0004vH-FD for qemu-devel@nongnu.org; Mon, 08 Sep 2014 05:18:04 -0400 Received: by mail-wi0-f170.google.com with SMTP id cc10so2284819wib.3 for ; Mon, 08 Sep 2014 02:18:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=pQfZmP+gH7Jvevv9e06G0GBCog2aOZmIM8GyM57xnRs=; b=QPi4pkpNI3qUPexBf/5YUyrLJ0l+QLb+zQyMwJf+k+5JjUYqXG4nfHPCCo4Od98Z5z odw3OyPDKGqyrX8yhEh9fni7XSSAjuFtJ7TfeAZ0zIRAwGkqbsz3cEFMVBu63etzZECR k7xIurOXz2Qw7sy9yVXvIUXvan00B0xP1RqMtullFih77aGOU8W5td9r/DraGXNkUgXb vtDzy7jljCV9I1saqj6BAAMv1FGpmCL1hq0aw8mApMght+PXIxD61JOrZMu2gmi2IcrM 6Xp06TXMrxv8HRbGTN+xNku4MNJNweSmdmtZvvu4Fmd5xRbn0lQlNmiCHXJTyiRupP+r EgBw== X-Gm-Message-State: ALoCoQlHgwStsKC3Dl6jcftcRiaYEVGST2i1non9n+vwc/k4gW9xsuZ8EMEO9vBqNtXWJH0jDg1d X-Received: by 10.180.103.234 with SMTP id fz10mr21445181wib.76.1410167883771; Mon, 08 Sep 2014 02:18:03 -0700 (PDT) Received: from alcyon.dev.6wind.com (guy78-3-82-239-227-177.fbx.proxad.net. [82.239.227.177]) by mx.google.com with ESMTPSA id wr10sm10420808wjc.10.2014.09.08.02.18.02 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Sep 2014 02:18:03 -0700 (PDT) From: David Marchand To: qemu-devel@nongnu.org Date: Mon, 8 Sep 2014 11:17:50 +0200 Message-Id: <1410167870-680-4-git-send-email-david.marchand@6wind.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1410167870-680-1-git-send-email-david.marchand@6wind.com> References: <1410167870-680-1-git-send-email-david.marchand@6wind.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.85.212.170 Cc: kvm@vger.kernel.org, mst@redhat.com, stefanha@gmail.com, claudio.fontana@huawei.com, armbru@redhat.com, arei.gonglei@huawei.com, mkletzan@redhat.com, pbonzini@redhat.com, jani.kokkonen@huawei.com, cam@cs.ualberta.ca Subject: [Qemu-devel] [PATCH v6 3/3] ivshmem: add check on protocol version in QEMU 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 Send a protocol version as the first message from server, clients must close communication if they don't support this protocol version. Older QEMUs should be fine with this change in the protocol since they overrides their own vm_id on reception of an id associated to no eventfd. Signed-off-by: David Marchand --- contrib/ivshmem-client/ivshmem-client.c | 13 ++++++++++--- contrib/ivshmem-client/ivshmem-client.h | 1 + contrib/ivshmem-server/ivshmem-server.c | 9 +++++++++ contrib/ivshmem-server/ivshmem-server.h | 1 + docs/specs/ivshmem_device_spec.txt | 9 ++++++--- hw/misc/ivshmem.c | 27 +++++++++++++++++++++++++-- include/hw/misc/ivshmem.h | 17 +++++++++++++++++ 7 files changed, 69 insertions(+), 8 deletions(-) create mode 100644 include/hw/misc/ivshmem.h diff --git a/contrib/ivshmem-client/ivshmem-client.c b/contrib/ivshmem-client/ivshmem-client.c index 11c805c..4413e26 100644 --- a/contrib/ivshmem-client/ivshmem-client.c +++ b/contrib/ivshmem-client/ivshmem-client.c @@ -201,10 +201,17 @@ ivshmem_client_connect(IvshmemClient *client) goto err_close; } - /* first, we expect our index + a fd == -1 */ + /* first, we expect a protocol version */ + if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 || + (tmp != IVSHMEM_PROTOCOL_VERSION) || fd != -1) { + IVSHMEM_CLIENT_DEBUG(client, "cannot read from server\n"); + goto err_close; + } + + /* then, we expect our index + a fd == -1 */ if (ivshmem_client_read_one_msg(client, &client->local.id, &fd) < 0 || client->local.id < 0 || fd != -1) { - IVSHMEM_CLIENT_DEBUG(client, "cannot read from server\n"); + IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n"); goto err_close; } IVSHMEM_CLIENT_DEBUG(client, "our_id=%ld\n", client->local.id); @@ -216,7 +223,7 @@ ivshmem_client_connect(IvshmemClient *client) if (fd >= 0) { close(fd); } - IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n"); + IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (3)\n"); goto err_close; } client->shm_fd = fd; diff --git a/contrib/ivshmem-client/ivshmem-client.h b/contrib/ivshmem-client/ivshmem-client.h index 284c4a3..9215f34 100644 --- a/contrib/ivshmem-client/ivshmem-client.h +++ b/contrib/ivshmem-client/ivshmem-client.h @@ -23,6 +23,7 @@ #include #include "qemu/queue.h" +#include "hw/misc/ivshmem.h" /** * Maximum number of notification vectors supported by the client diff --git a/contrib/ivshmem-server/ivshmem-server.c b/contrib/ivshmem-server/ivshmem-server.c index 91dc208..ea290f6 100644 --- a/contrib/ivshmem-server/ivshmem-server.c +++ b/contrib/ivshmem-server/ivshmem-server.c @@ -99,6 +99,15 @@ ivshmem_server_send_initial_info(IvshmemServer *server, IvshmemServerPeer *peer) { int ret; + /* send our protocol version first */ + ret = ivshmem_server_send_one_msg(peer->sock_fd, IVSHMEM_PROTOCOL_VERSION, + -1); + if (ret < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot send version: %s\n", + strerror(errno)); + return -1; + } + /* send the peer id to the client */ ret = ivshmem_server_send_one_msg(peer->sock_fd, peer->id, -1); if (ret < 0) { diff --git a/contrib/ivshmem-server/ivshmem-server.h b/contrib/ivshmem-server/ivshmem-server.h index f85dcd2..38df7bb 100644 --- a/contrib/ivshmem-server/ivshmem-server.h +++ b/contrib/ivshmem-server/ivshmem-server.h @@ -30,6 +30,7 @@ #include #include "qemu/queue.h" +#include "hw/misc/ivshmem.h" /** * Maximum number of notification vectors supported by the server diff --git a/docs/specs/ivshmem_device_spec.txt b/docs/specs/ivshmem_device_spec.txt index 12f338e..3435116 100644 --- a/docs/specs/ivshmem_device_spec.txt +++ b/docs/specs/ivshmem_device_spec.txt @@ -64,6 +64,8 @@ It creates a shared memory object then waits for clients to connect on a unix socket. For each client (QEMU process) that connects to the server: +- the server sends a protocol version, if client does not support it, the client + closes the communication, - the server assigns an ID for this client and sends this ID to him as the first message, - the server sends a fd to the shared memory object to this client, @@ -86,9 +88,10 @@ been provided in qemu.git/contrib/ivshmem-client for debug. *QEMU as an ivshmem client* -At initialisation, when creating the ivshmem device, QEMU gets its ID from the -server then makes it available through BAR0 IVPosition register for the VM to -use (see 'PCI device registers' subsection). +At initialisation, when creating the ivshmem device, QEMU first receives a +protocol version and closes communication with server if it does not match. +Then, QEMU gets its ID from the server then makes it available through BAR0 +IVPosition register for the VM to use (see 'PCI device registers' subsection). QEMU then uses the fd to the shared memory to map it to BAR2. eventfds for all other clients received from the server are stored to implement BAR0 Doorbell register (see 'PCI device registers' subsection). diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index bd9d718..e08632b 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -26,6 +26,8 @@ #include "qemu/event_notifier.h" #include "sysemu/char.h" +#include "hw/misc/ivshmem.h" + #include #include @@ -528,6 +530,27 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags) } } +static void ivshmem_check_version(void *opaque, const uint8_t * buf, int flags) +{ + IVShmemState *s = opaque; + int tmp; + long version; + + memcpy(&version, buf, sizeof(long)); + tmp = qemu_chr_fe_get_msgfd(s->server_chr); + if (tmp != -1 || version != IVSHMEM_PROTOCOL_VERSION) { + fprintf(stderr, "incompatible version, you are connecting to a ivshmem-" + "server using a different protocol please check your setup\n"); + qemu_chr_delete(s->server_chr); + s->server_chr = NULL; + return; + } + + IVSHMEM_DPRINTF("version check ok, switch to real chardev handler\n"); + qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read, + ivshmem_event, s); +} + /* Select the MSI-X vectors used by device. * ivshmem maps events to vectors statically, so * we just enable all vectors on init and after reset. */ @@ -742,8 +765,8 @@ static int pci_ivshmem_init(PCIDevice *dev) s->eventfd_chr = g_malloc0(s->vectors * sizeof(CharDriverState *)); - qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read, - ivshmem_event, s); + qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, + ivshmem_check_version, ivshmem_event, s); } else { /* just map the file immediately, we're not using a server */ int fd; diff --git a/include/hw/misc/ivshmem.h b/include/hw/misc/ivshmem.h new file mode 100644 index 0000000..22c9f1f --- /dev/null +++ b/include/hw/misc/ivshmem.h @@ -0,0 +1,17 @@ +/* + * Copyright 6WIND S.A., 2014 + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * (at your option) any later version. See the COPYING file in the + * top-level directory. + */ + +#ifndef _IVSHMEM_H_ +#define _IVSHMEM_H_ + +/** + * Protocol version + */ +#define IVSHMEM_PROTOCOL_VERSION 0x0 + +#endif