Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932510Ab0DGI6I (ORCPT ); Wed, 7 Apr 2010 04:58:08 -0400 Received: from mga03.intel.com ([143.182.124.21]:61311 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932238Ab0DGI55 (ORCPT ); Wed, 7 Apr 2010 04:57:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.51,377,1267430400"; d="scan'208";a="262910094" From: xiaohui.xin@intel.com To: mst@redhat.com Cc: netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu, jdike@linux.intel.com, Xin Xiaohui Subject: Re:[PATCH 1/3] A device for zero-copy based on KVM virtio-net. Date: Wed, 7 Apr 2010 17:00:39 +0800 Message-Id: <1270630839-19876-1-git-send-email-xiaohui.xin@intel.com> X-Mailer: git-send-email 1.5.4.4 In-Reply-To: <20100407081532.GB9550@redhat.com> References: <20100407081532.GB9550@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2303 Lines: 85 From: Xin Xiaohui --- Michael, Thanks a lot for the explanation. I have drafted a patch for the qemu write after I looked into tun driver. Does it do in right way? Thanks Xiaohui drivers/vhost/mpassthru.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 45 insertions(+), 0 deletions(-) diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c index e9449ac..1cde097 100644 --- a/drivers/vhost/mpassthru.c +++ b/drivers/vhost/mpassthru.c @@ -1065,6 +1065,49 @@ static unsigned int mp_chr_poll(struct file *file, poll_table * wait) return mask; } +static ssize_t mp_chr_aio_write(struct kiocb *iocb, const struct iovec *iov, + unsigned long count, loff_t pos) +{ + struct file *file = iocb->ki_filp; + struct mp_struct *mp = mp_get(file->private_data); + struct sock *sk = mp->socket.sk; + struct sk_buff *skb; + int len, err; + ssize_t result; + + if (!mp) + return -EBADFD; + + /* currently, async is not supported */ + if (!is_sync_kiocb(iocb)) + return -EFAULT; + + len = iov_length(iov, count); + skb = sock_alloc_send_skb(sk, len + NET_IP_ALIGN, + file->f_flags & O_NONBLOCK, &err); + + if (!skb) + return -EFAULT; + + skb_reserve(skb, NET_IP_ALIGN); + skb_put(skb, len); + + if (skb_copy_datagram_from_iovec(skb, 0, iov, 0, len)) { + kfree_skb(skb); + return -EFAULT; + } + skb_set_network_header(skb, ETH_HLEN); + skb->protocol = *((__be16 *)(skb->data) + ETH_ALEN); + skb->dev = mp->dev; + + dev_queue_xmit(skb); + mp->dev->stats.tx_packets++; + mp->dev->stats.tx_bytes += len; + + mp_put(mp); + return result; +} + static int mp_chr_close(struct inode *inode, struct file *file) { struct mp_file *mfile = file->private_data; @@ -1084,6 +1127,8 @@ static int mp_chr_close(struct inode *inode, struct file *file) static const struct file_operations mp_fops = { .owner = THIS_MODULE, .llseek = no_llseek, + .write = do_sync_write, + .aio_write = mp_chr_aio_write, .poll = mp_chr_poll, .unlocked_ioctl = mp_chr_ioctl, .open = mp_chr_open, -- 1.5.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/