Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751404AbdFBTcm (ORCPT ); Fri, 2 Jun 2017 15:32:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:55996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751218AbdFBTcD (ORCPT ); Fri, 2 Jun 2017 15:32:03 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA85323A31 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=sstabellini@kernel.org From: Stefano Stabellini To: xen-devel@lists.xen.org Cc: linux-kernel@vger.kernel.org, sstabellini@kernel.org, jgross@suse.com, boris.ostrovsky@oracle.com, Stefano Stabellini Subject: [PATCH v3 17/18] xen/pvcalls: implement write Date: Fri, 2 Jun 2017 12:31:54 -0700 Message-Id: <1496431915-20774-17-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1496431915-20774-1-git-send-email-sstabellini@kernel.org> References: <1496431915-20774-1-git-send-email-sstabellini@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3126 Lines: 110 When the other end notifies us that there is data to be written (pvcalls_back_conn_event), increment the io and write counters, and schedule the ioworker. Implement the write function called by ioworker by reading the data from the data ring, writing it to the socket by calling inet_sendmsg. Set out_error on error. Signed-off-by: Stefano Stabellini CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-back.c | 74 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 73 insertions(+), 1 deletion(-) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index e7d2b85..fe3e70f 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -180,7 +180,66 @@ static void pvcalls_conn_back_read(unsigned long opaque) static int pvcalls_conn_back_write(struct sock_mapping *map) { - return 0; + struct pvcalls_data_intf *intf = map->ring; + struct pvcalls_data *data = &map->data; + struct msghdr msg; + struct kvec vec[2]; + RING_IDX cons, prod, size, ring_size; + int ret; + + cons = intf->out_cons; + prod = intf->out_prod; + /* read the indexes before dealing with the data */ + virt_mb(); + + ring_size = XEN_FLEX_RING_SIZE(map->ring_order); + size = pvcalls_queued(prod, cons, ring_size); + if (size == 0) + return 0; + + memset(&msg, 0, sizeof(msg)); + msg.msg_flags |= MSG_DONTWAIT; + msg.msg_iter.type = ITER_KVEC|READ; + msg.msg_iter.count = size; + if (pvcalls_mask(prod, ring_size) > pvcalls_mask(cons, ring_size)) { + vec[0].iov_base = data->out + pvcalls_mask(cons, ring_size); + vec[0].iov_len = size; + msg.msg_iter.kvec = vec; + msg.msg_iter.nr_segs = 1; + } else { + vec[0].iov_base = data->out + pvcalls_mask(cons, ring_size); + vec[0].iov_len = ring_size - pvcalls_mask(cons, ring_size); + vec[1].iov_base = data->out; + vec[1].iov_len = size - vec[0].iov_len; + msg.msg_iter.kvec = vec; + msg.msg_iter.nr_segs = 2; + } + + atomic_set(&map->write, 0); + ret = inet_sendmsg(map->sock, &msg, size); + if (ret == -EAGAIN || ret < size) { + atomic_inc(&map->write); + atomic_inc(&map->io); + } + if (ret == -EAGAIN) + return ret; + + /* write the data, then update the indexes */ + virt_wmb(); + if (ret < 0) { + intf->out_error = ret; + } else { + intf->out_error = 0; + intf->out_cons = cons + ret; + prod = intf->out_prod; + } + /* update the indexes, then notify the other end */ + virt_wmb(); + if (prod != cons + ret) + atomic_inc(&map->write); + notify_remote_via_irq(map->irq); + + return ret; } static void pvcalls_back_ioworker(struct work_struct *work) @@ -837,6 +896,19 @@ static irqreturn_t pvcalls_back_event(int irq, void *dev_id) static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map) { + struct sock_mapping *map = sock_map; + struct pvcalls_ioworker *iow; + + if (map == NULL || map->sock == NULL || map->sock->sk == NULL || + map->sock->sk->sk_user_data != map) + return IRQ_HANDLED; + + iow = &map->ioworker; + + atomic_inc(&map->write); + atomic_inc(&map->io); + queue_work_on(iow->cpu, iow->wq, &iow->register_work); + return IRQ_HANDLED; } -- 1.9.1