6 files changed, 54 insertions, 19 deletions

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index b4ee163154a6..ee418701cdee 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -882,6 +882,16 @@ s64 vsock_stream_has_space(struct vsock_sock *vsk)
 }
 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 
+void vsock_data_ready(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
+	    sock_flag(sk, SOCK_DONE))
+		sk->sk_data_ready(sk);
+}
+EXPORT_SYMBOL_GPL(vsock_data_ready);
+
 static int vsock_release(struct socket *sock)
 {
 	__vsock_release(sock->sk, 0);
@@ -1066,8 +1076,9 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
 		if (transport && transport->stream_is_active(vsk) &&
 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
 			bool data_ready_now = false;
+			int target = sock_rcvlowat(sk, 0, INT_MAX);
 			int ret = transport->notify_poll_in(
-					vsk, 1, &data_ready_now);
+					vsk, target, &data_ready_now);
 			if (ret < 0) {
 				mask |= EPOLLERR;
 			} else {
@@ -2137,6 +2148,25 @@ out:
 	return err;
 }
 
+static int vsock_set_rcvlowat(struct sock *sk, int val)
+{
+	const struct vsock_transport *transport;
+	struct vsock_sock *vsk;
+
+	vsk = vsock_sk(sk);
+
+	if (val > vsk->buffer_size)
+		return -EINVAL;
+
+	transport = vsk->transport;
+
+	if (transport && transport->set_rcvlowat)
+		return transport->set_rcvlowat(vsk, val);
+
+	WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
+	return 0;
+}
+
 static const struct proto_ops vsock_stream_ops = {
 	.family = PF_VSOCK,
 	.owner = THIS_MODULE,
@@ -2156,6 +2186,7 @@ static const struct proto_ops vsock_stream_ops = {
 	.recvmsg = vsock_connectible_recvmsg,
 	.mmap = sock_no_mmap,
 	.sendpage = sock_no_sendpage,
+	.set_rcvlowat = vsock_set_rcvlowat,
 };
 
 static const struct proto_ops vsock_seqpacket_ops = {
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index fd98229e3db3..59c3e2697069 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -815,6 +815,12 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
 	return 0;
 }
 
+static
+int hvs_set_rcvlowat(struct vsock_sock *vsk, int val)
+{
+	return -EOPNOTSUPP;
+}
+
 static struct vsock_transport hvs_transport = {
 	.module                   = THIS_MODULE,
 
@@ -850,6 +856,7 @@ static struct vsock_transport hvs_transport = {
 	.notify_send_pre_enqueue  = hvs_notify_send_pre_enqueue,
 	.notify_send_post_enqueue = hvs_notify_send_post_enqueue,
 
+	.set_rcvlowat             = hvs_set_rcvlowat
 };
 
 static bool hvs_check_transport(struct vsock_sock *vsk)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index ec2c2afbf0d0..a9980e9b9304 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -634,10 +634,7 @@ virtio_transport_notify_poll_in(struct vsock_sock *vsk,
 				size_t target,
 				bool *data_ready_now)
 {
-	if (vsock_stream_has_data(vsk))
-		*data_ready_now = true;
-	else
-		*data_ready_now = false;
+	*data_ready_now = vsock_stream_has_data(vsk) >= target;
 
 	return 0;
 }
@@ -1084,7 +1081,7 @@ virtio_transport_recv_connected(struct sock *sk,
 	switch (le16_to_cpu(pkt->hdr.op)) {
 	case VIRTIO_VSOCK_OP_RW:
 		virtio_transport_recv_enqueue(vsk, pkt);
-		sk->sk_data_ready(sk);
+		vsock_data_ready(sk);
 		return err;
 	case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
 		virtio_transport_send_credit_update(vsk);
@@ -1342,7 +1339,7 @@ EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
 
 void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
 {
-	kfree(pkt->buf);
+	kvfree(pkt->buf);
 	kfree(pkt);
 }
 EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index b14f0ed7427b..842c94286d31 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -951,7 +951,7 @@ static int vmci_transport_recv_listen(struct sock *sk,
 	 * for ourself or any previous connection requests that we received.
 	 * If it's the latter, we try to find a socket in our list of pending
 	 * connections and, if we do, call the appropriate handler for the
-	 * state that that socket is in.  Otherwise we try to service the
+	 * state that socket is in.  Otherwise we try to service the
 	 * connection request.
 	 */
 	pending = vmci_transport_get_pending(sk, pkt);
diff --git a/net/vmw_vsock/vmci_transport_notify.c b/net/vmw_vsock/vmci_transport_notify.c
index d69fc4b595ad..7c3a7db134b2 100644
--- a/net/vmw_vsock/vmci_transport_notify.c
+++ b/net/vmw_vsock/vmci_transport_notify.c
@@ -307,7 +307,7 @@ vmci_transport_handle_wrote(struct sock *sk,
 	struct vsock_sock *vsk = vsock_sk(sk);
 	PKT_FIELD(vsk, sent_waiting_read) = false;
 #endif
-	sk->sk_data_ready(sk);
+	vsock_data_ready(sk);
 }
 
 static void vmci_transport_notify_pkt_socket_init(struct sock *sk)
@@ -340,12 +340,12 @@ vmci_transport_notify_pkt_poll_in(struct sock *sk,
 {
 	struct vsock_sock *vsk = vsock_sk(sk);
 
-	if (vsock_stream_has_data(vsk)) {
+	if (vsock_stream_has_data(vsk) >= target) {
 		*data_ready_now = true;
 	} else {
-		/* We can't read right now because there is nothing in the
-		 * queue. Ask for notifications when there is something to
-		 * read.
+		/* We can't read right now because there is not enough data
+		 * in the queue. Ask for notifications when there is something
+		 * to read.
 		 */
 		if (sk->sk_state == TCP_ESTABLISHED) {
 			if (!send_waiting_read(sk, 1))
diff --git a/net/vmw_vsock/vmci_transport_notify_qstate.c b/net/vmw_vsock/vmci_transport_notify_qstate.c
index 0f36d7c45db3..e96a88d850a8 100644
--- a/net/vmw_vsock/vmci_transport_notify_qstate.c
+++ b/net/vmw_vsock/vmci_transport_notify_qstate.c
@@ -84,7 +84,7 @@ vmci_transport_handle_wrote(struct sock *sk,
 			    bool bottom_half,
 			    struct sockaddr_vm *dst, struct sockaddr_vm *src)
 {
-	sk->sk_data_ready(sk);
+	vsock_data_ready(sk);
 }
 
 static void vsock_block_update_write_window(struct sock *sk)
@@ -161,12 +161,12 @@ vmci_transport_notify_pkt_poll_in(struct sock *sk,
 {
 	struct vsock_sock *vsk = vsock_sk(sk);
 
-	if (vsock_stream_has_data(vsk)) {
+	if (vsock_stream_has_data(vsk) >= target) {
 		*data_ready_now = true;
 	} else {
-		/* We can't read right now because there is nothing in the
-		 * queue. Ask for notifications when there is something to
-		 * read.
+		/* We can't read right now because there is not enough data
+		 * in the queue. Ask for notifications when there is something
+		 * to read.
 		 */
 		if (sk->sk_state == TCP_ESTABLISHED)
 			vsock_block_update_write_window(sk);
@@ -282,7 +282,7 @@ vmci_transport_notify_pkt_recv_post_dequeue(
 		/* See the comment in
 		 * vmci_transport_notify_pkt_send_post_enqueue().
 		 */
-		sk->sk_data_ready(sk);
+		vsock_data_ready(sk);
 	}
 
 	return err;