From patchwork Fri Apr 14 17:40:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Maxime Coquelin X-Patchwork-Id: 9681521 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6C17260384 for ; Fri, 14 Apr 2017 17:44:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 60B8428662 for ; Fri, 14 Apr 2017 17:44:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 54E6E286CB; Fri, 14 Apr 2017 17:44:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id A84EF28662 for ; Fri, 14 Apr 2017 17:44:33 +0000 (UTC) Received: from localhost ([::1]:54103 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cz5Gr-0006Ia-0u for patchwork-qemu-devel@patchwork.kernel.org; Fri, 14 Apr 2017 13:44:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48725) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cz5EI-0004b5-0J for qemu-devel@nongnu.org; Fri, 14 Apr 2017 13:41:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cz5ED-0005to-VR for qemu-devel@nongnu.org; Fri, 14 Apr 2017 13:41:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36322) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cz5ED-0005tI-Lf for qemu-devel@nongnu.org; Fri, 14 Apr 2017 13:41:49 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8B2FF51459; Fri, 14 Apr 2017 17:41:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8B2FF51459 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=maxime.coquelin@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 8B2FF51459 Received: from localhost.localdomain (ovpn-112-20.ams2.redhat.com [10.36.112.20]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6C87517493; Fri, 14 Apr 2017 17:41:38 +0000 (UTC) From: Maxime Coquelin To: mst@redhat.com, marcandre.lureau@gmail.com, vkaplans@redhat.com, jasowang@redhat.com, wexu@redhat.com, peterx@redhat.com, yuanhan.liu@linux.intel.com, qemu-devel@nongnu.org Date: Fri, 14 Apr 2017 19:40:55 +0200 Message-Id: <20170414174056.28946-4-maxime.coquelin@redhat.com> In-Reply-To: <20170414174056.28946-1-maxime.coquelin@redhat.com> References: <20170414174056.28946-1-maxime.coquelin@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 14 Apr 2017 17:41:48 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC v2 3/4] vhost-user: add slave-req-fd support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Maxime Coquelin Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Marc-André Lureau Learn to give a socket to the slave to let him make requests to the master. Signed-off-by: Marc-André Lureau Signed-off-by: Maxime Coquelin --- docs/specs/vhost-user.txt | 30 +++++++++++- hw/virtio/vhost-user.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 145 insertions(+), 2 deletions(-) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 036890f..49c6293 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -139,6 +139,7 @@ in the ancillary data: * VHOST_USER_SET_VRING_KICK * VHOST_USER_SET_VRING_CALL * VHOST_USER_SET_VRING_ERR + * VHOST_USER_SET_SLAVE_REQ_FD If Master is unable to send the full message or receives a wrong reply it will close the connection. An optional reconnection mechanism can be implemented. @@ -252,6 +253,18 @@ Once the source has finished migration, rings will be stopped by the source. No further update must be done before rings are restarted. +Slave communication +------------------- + +An optional communication channel is provided if the slave declares +VHOST_USER_PROTOCOL_F_SLAVE_REQ protocol feature, to allow the slave to make +requests to the master. + +The fd is provided via VHOST_USER_SET_SLAVE_REQ_FD ancillary data. + +A slave may then send VHOST_USER_SLAVE_* messages to the master +using this fd communication channel. + Protocol features ----------------- @@ -260,9 +273,10 @@ Protocol features #define VHOST_USER_PROTOCOL_F_RARP 2 #define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 #define VHOST_USER_PROTOCOL_F_MTU 4 +#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5 -Message types -------------- +Master message types +-------------------- * VHOST_USER_GET_FEATURES @@ -486,6 +500,18 @@ Message types If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond with zero in case the specified MTU is valid, or non-zero otherwise. + * VHOST_USER_SET_SLAVE_REQ_FD + + Id: 21 + Equivalent ioctl: N/A + Master payload: N/A + + Set the socket file descriptor for slave initiated requests. It is passed + in the ancillary data. + This request should be sent only when VHOST_USER_F_PROTOCOL_FEATURES + has been negotiated, and protocol feature bit VHOST_USER_PROTOCOL_F_SLAVE_REQ + bit is present in VHOST_USER_GET_PROTOCOL_FEATURES. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index f0e10d0..f26f11b 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -33,6 +33,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_RARP = 2, VHOST_USER_PROTOCOL_F_REPLY_ACK = 3, VHOST_USER_PROTOCOL_F_NET_MTU = 4, + VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5, VHOST_USER_PROTOCOL_F_MAX }; @@ -61,9 +62,15 @@ typedef enum VhostUserRequest { VHOST_USER_SET_VRING_ENABLE = 18, VHOST_USER_SEND_RARP = 19, VHOST_USER_NET_SET_MTU = 20, + VHOST_USER_SET_SLAVE_REQ_FD = 21, VHOST_USER_MAX } VhostUserRequest; +typedef enum VhostUserSlaveRequest { + VHOST_USER_SLAVE_NONE = 0, + VHOST_USER_SLAVE_MAX +} VhostUserSlaveRequest; + typedef struct VhostUserMemoryRegion { uint64_t guest_phys_addr; uint64_t memory_size; @@ -113,6 +120,7 @@ static VhostUserMsg m __attribute__ ((unused)); struct vhost_user { CharBackend *chr; + int slave_fd; }; static bool ioeventfd_enabled(void) @@ -574,6 +582,104 @@ static int vhost_user_reset_device(struct vhost_dev *dev) return 0; } +static void slave_read(void *opaque) +{ + struct vhost_dev *dev = opaque; + struct vhost_user *u = dev->opaque; + VhostUserMsg msg = { 0, }; + int size, ret = 0; + + /* Read header */ + size = read(u->slave_fd, &msg, VHOST_USER_HDR_SIZE); + if (size != VHOST_USER_HDR_SIZE) { + error_report("Failed to read from slave."); + goto err; + } + + if (msg.size > VHOST_USER_PAYLOAD_SIZE) { + error_report("Failed to read msg header." + " Size %d exceeds the maximum %zu.", msg.size, + VHOST_USER_PAYLOAD_SIZE); + goto err; + } + + /* Read payload */ + size = read(u->slave_fd, &msg.payload, msg.size); + if (size != msg.size) { + error_report("Failed to read payload from slave."); + goto err; + } + + switch (msg.request) { + default: + error_report("Received unexpected msg type."); + ret = -EINVAL; + } + + /* + * REPLY_ACK feature handling. Other reply types has to be managed + * directly in their request handlers. + */ + if (msg.flags & VHOST_USER_NEED_REPLY_MASK) { + msg.flags &= ~VHOST_USER_NEED_REPLY_MASK; + msg.flags |= VHOST_USER_REPLY_MASK; + + msg.payload.u64 = !!ret; + msg.size = sizeof(msg.payload.u64); + + size = write(u->slave_fd, &msg, VHOST_USER_HDR_SIZE + msg.size); + if (size != VHOST_USER_HDR_SIZE + msg.size) { + error_report("Failed to send msg reply to slave."); + goto err; + } + } + + return; + +err: + qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL); + close(u->slave_fd); + u->slave_fd = -1; + return; +} + +static int vhost_setup_slave_channel(struct vhost_dev *dev) +{ + VhostUserMsg msg = { + .request = VHOST_USER_SET_SLAVE_REQ_FD, + .flags = VHOST_USER_VERSION, + }; + struct vhost_user *u = dev->opaque; + int sv[2]; + bool reply_supported = virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_REPLY_ACK); + + if (!virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_SLAVE_REQ)) { + return 0; + } + + if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { + error_report("socketpair() failed"); + return -1; + } + + u->slave_fd = sv[0]; + qemu_set_fd_handler(u->slave_fd, slave_read, NULL, dev); + + if (reply_supported) { + msg.flags |= VHOST_USER_NEED_REPLY_MASK; + } + + vhost_user_write(dev, &msg, &sv[1], 1); + + if (reply_supported) { + return process_message_reply(dev, msg.request); + } + + return 0; +} + static int vhost_user_init(struct vhost_dev *dev, void *opaque) { uint64_t features; @@ -584,6 +690,7 @@ static int vhost_user_init(struct vhost_dev *dev, void *opaque) u = g_new0(struct vhost_user, 1); u->chr = opaque; + u->slave_fd = -1; dev->opaque = u; err = vhost_user_get_features(dev, &features); @@ -624,6 +731,12 @@ static int vhost_user_init(struct vhost_dev *dev, void *opaque) "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature."); } + + err = vhost_setup_slave_channel(dev); + if (err < 0) { + return err; + } + return 0; } @@ -634,6 +747,10 @@ static int vhost_user_cleanup(struct vhost_dev *dev) assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER); u = dev->opaque; + if (u->slave_fd >= 0) { + close(u->slave_fd); + u->slave_fd = -1; + } g_free(u); dev->opaque = 0;