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authorStefano Stabellini <sstabellini@kernel.org>2017-07-06 11:01:08 -0700
committerBoris Ostrovsky <boris.ostrovsky@oracle.com>2017-08-31 09:45:55 -0400
commit5ad9918ffc4157f239f2e7849b4987d3b20f917e (patch)
tree6c2a8dc4e33440b1375960a81b62fd715c3f1941 /drivers/xen
parentb3f9f773af1f925b35f73f5e946bd96728b96cca (diff)
downloadlinux-5ad9918ffc4157f239f2e7849b4987d3b20f917e.tar.bz2
xen/pvcalls: implement write
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 <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/pvcalls-back.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index 2519e46bd470..3201a0c5dbcf 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -177,6 +177,64 @@ static void pvcalls_conn_back_read(void *opaque)
static void pvcalls_conn_back_write(struct sock_mapping *map)
{
+ 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, array_size;
+ int ret;
+
+ cons = intf->out_cons;
+ prod = intf->out_prod;
+ /* read the indexes before dealing with the data */
+ virt_mb();
+
+ array_size = XEN_FLEX_RING_SIZE(map->ring_order);
+ size = pvcalls_queued(prod, cons, array_size);
+ if (size == 0)
+ return;
+
+ 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, array_size) > pvcalls_mask(cons, array_size)) {
+ vec[0].iov_base = data->out + pvcalls_mask(cons, array_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, array_size);
+ vec[0].iov_len = array_size - pvcalls_mask(cons, array_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 >= 0 && ret < size)) {
+ atomic_inc(&map->write);
+ atomic_inc(&map->io);
+ }
+ if (ret == -EAGAIN)
+ return;
+
+ /* 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);
}
static void pvcalls_back_ioworker(struct work_struct *work)
@@ -847,6 +905,19 @@ 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(iow->wq, &iow->register_work);
+
return IRQ_HANDLED;
}