From patchwork Thu Apr 4 10:58:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 1077121 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44Zg1c4jBxz9ryj for ; Thu, 4 Apr 2019 21:59:16 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729753AbfDDK6w (ORCPT ); Thu, 4 Apr 2019 06:58:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38904 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729718AbfDDK6w (ORCPT ); Thu, 4 Apr 2019 06:58:52 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 091DC19D39B; Thu, 4 Apr 2019 10:58:52 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-117-25.ams2.redhat.com [10.36.117.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id B52FB1001E65; Thu, 4 Apr 2019 10:58:49 +0000 (UTC) From: Stefano Garzarella To: netdev@vger.kernel.org Cc: Jason Wang , "Michael S. Tsirkin" , Stefan Hajnoczi , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "David S. Miller" Subject: [PATCH RFC 2/4] vhost/vsock: split packets to send using multiple buffers Date: Thu, 4 Apr 2019 12:58:36 +0200 Message-Id: <20190404105838.101559-3-sgarzare@redhat.com> In-Reply-To: <20190404105838.101559-1-sgarzare@redhat.com> References: <20190404105838.101559-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 04 Apr 2019 10:58:52 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If the packets to sent to the guest are bigger than the buffer available, we can split them, using multiple buffers and fixing the length in the packet header. This is safe since virtio-vsock supports only stream sockets. Signed-off-by: Stefano Garzarella --- drivers/vhost/vsock.c | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index bb5fc0e9fbc2..9951b7e661f6 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -94,7 +94,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, struct iov_iter iov_iter; unsigned out, in; size_t nbytes; - size_t len; + size_t iov_len, payload_len; int head; spin_lock_bh(&vsock->send_pkt_list_lock); @@ -139,8 +139,18 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, break; } - len = iov_length(&vq->iov[out], in); - iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len); + payload_len = pkt->len - pkt->off; + iov_len = iov_length(&vq->iov[out], in); + iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len); + + /* If the packet is greater than the space available in the + * buffer, we split it using multiple buffers. + */ + if (payload_len > iov_len - sizeof(pkt->hdr)) + payload_len = iov_len - sizeof(pkt->hdr); + + /* Set the correct length in the header */ + pkt->hdr.len = cpu_to_le32(payload_len); nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter); if (nbytes != sizeof(pkt->hdr)) { @@ -149,16 +159,29 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, break; } - nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter); - if (nbytes != pkt->len) { + nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len, + &iov_iter); + if (nbytes != payload_len) { virtio_transport_free_pkt(pkt); vq_err(vq, "Faulted on copying pkt buf\n"); break; } - vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len); + vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len); added = true; + pkt->off += payload_len; + + /* If we didn't send all the payload we can requeue the packet + * to send it with the next available buffer. + */ + if (pkt->off < pkt->len) { + spin_lock_bh(&vsock->send_pkt_list_lock); + list_add(&pkt->list, &vsock->send_pkt_list); + spin_unlock_bh(&vsock->send_pkt_list_lock); + continue; + } + if (pkt->reply) { int val;