From patchwork Fri Jan 16 21:13:23 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 2890 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n0GLBCjd016381 for ; Fri, 16 Jan 2009 13:11:13 -0800 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763635AbZAPVPU (ORCPT ); Fri, 16 Jan 2009 16:15:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763578AbZAPVPT (ORCPT ); Fri, 16 Jan 2009 16:15:19 -0500 Received: from g4t0017.houston.hp.com ([15.201.24.20]:39974 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763245AbZAPVPQ (ORCPT ); Fri, 16 Jan 2009 16:15:16 -0500 Received: from g1t0039.austin.hp.com (g1t0039.austin.hp.com [16.236.32.45]) by g4t0017.houston.hp.com (Postfix) with ESMTP id 342BE381D5; Fri, 16 Jan 2009 21:15:16 +0000 (UTC) Received: from ldl.fc.hp.com (ldl.fc.hp.com [15.11.146.30]) by g1t0039.austin.hp.com (Postfix) with ESMTP id 0B6FE34018; Fri, 16 Jan 2009 21:15:16 +0000 (UTC) Received: from localhost (ldl.fc.hp.com [127.0.0.1]) by ldl.fc.hp.com (Postfix) with ESMTP id 8D32639C06E; Fri, 16 Jan 2009 14:15:15 -0700 (MST) X-Virus-Scanned: Debian amavisd-new at ldl.fc.hp.com Received: from ldl.fc.hp.com ([127.0.0.1]) by localhost (ldl.fc.hp.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KN1NArAIBS8q; Fri, 16 Jan 2009 14:15:15 -0700 (MST) Received: from debian.lart (lart.fc.hp.com [15.11.146.31]) by ldl.fc.hp.com (Postfix) with ESMTP id 056DD39C00D; Fri, 16 Jan 2009 14:15:14 -0700 (MST) From: Alex Williamson Subject: [PATCH 2/5] virtio_net: Add a virtqueue for outbound control commands To: netdev@vger.kernel.org Cc: rusty@rustcorp.com.au, markmc@redhat.com, kvm@vger.kernel.org Date: Fri, 16 Jan 2009 14:13:23 -0700 Message-ID: <20090116211323.22836.40477.stgit@debian.lart> In-Reply-To: <20090116211312.22836.34331.stgit@debian.lart> References: <20090116211312.22836.34331.stgit@debian.lart> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This will be used for RX mode, MAC filter table, VLAN filtering, etc... The control transaction consists of one or more "out" sg entries and one or more "in" sg entries. The first out entry contains a header defining the class and command. Additional out entries may provide data for the command. The last in entry provides a status response back from the command. Virtqueues typically run asynchronous, running a callback function when there's data in the channel. We can't readily make use of this in the command paths where we need to use this. Instead, we kick the virtqueue and spin. The kick causes an I/O write, triggering an immediate trap into the hypervisor. Signed-off-by: Alex Williamson Acked-by: Mark McLoughlin --- drivers/net/virtio_net.c | 49 +++++++++++++++++++++++++++++++++++++++++++- include/linux/virtio_net.h | 17 +++++++++++++++ 2 files changed, 65 insertions(+), 1 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index e7700de..d4be0a2 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -39,7 +39,7 @@ module_param(gso, bool, 0444); struct virtnet_info { struct virtio_device *vdev; - struct virtqueue *rvq, *svq; + struct virtqueue *rvq, *svq, *cvq; struct net_device *dev; struct napi_struct napi; @@ -603,6 +603,41 @@ static int virtnet_open(struct net_device *dev) return 0; } +static int virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, + void *data, unsigned int len) +{ + struct scatterlist sg[3]; + struct virtio_net_ctrl_hdr ctrl; + virtio_net_ctrl_ack status; + unsigned int tmp; + int i = 0; + + if (!vi->cvq) + return -EIO; + + sg_init_table(sg, len ? 3 : 2); + + sg_set_buf(&sg[i++], &ctrl, sizeof(ctrl)); + if (len) + sg_set_buf(&sg[i++], data, len); + sg_set_buf(&sg[i], &status, sizeof(status)); + + ctrl.class = class; + ctrl.cmd = cmd; + + status = ~0; + + if (vi->cvq->vq_ops->add_buf(vi->cvq, sg, i, 1, vi) != 0) + BUG(); + + vi->cvq->vq_ops->kick(vi->cvq); + + while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp)) + cpu_relax(); + + return status ? -EFAULT : 0; +} + static int virtnet_close(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); @@ -733,6 +768,14 @@ static int virtnet_probe(struct virtio_device *vdev) goto free_recv; } + /* + * Outbound control channel virtqueue. We can live without it, + * so don't go fatal if it's not there. + */ + vi->cvq = vdev->config->find_vq(vdev, 2, NULL); + if (IS_ERR(vi->cvq)) + vi->cvq = NULL; + /* Initialize our empty receive and send queues. */ skb_queue_head_init(&vi->recv); skb_queue_head_init(&vi->send); @@ -763,6 +806,8 @@ static int virtnet_probe(struct virtio_device *vdev) unregister: unregister_netdev(dev); free_send: + if (vi->cvq) + vdev->config->del_vq(vi->cvq); vdev->config->del_vq(vi->svq); free_recv: vdev->config->del_vq(vi->rvq); @@ -793,6 +838,8 @@ static void virtnet_remove(struct virtio_device *vdev) vdev->config->del_vq(vi->svq); vdev->config->del_vq(vi->rvq); + if (vi->cvq) + vdev->config->del_vq(vi->cvq); unregister_netdev(vi->dev); while (vi->pages) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 5cdd0aa..e2c1d81 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -53,4 +53,21 @@ struct virtio_net_hdr_mrg_rxbuf { __u16 num_buffers; /* Number of merged rx buffers */ }; +/* + * Control virtqueue data structures + * + * The control virtqueue expects a header in the first sg entry + * and an ack/status response in the last entry. Data for the + * command goes in between. + */ +struct virtio_net_ctrl_hdr { + __u8 class; + __u8 cmd; +}; + +typedef __u8 virtio_net_ctrl_ack; + +#define VIRTIO_NET_OK 0 +#define VIRTIO_NET_ERR 1 + #endif /* _LINUX_VIRTIO_NET_H */