[PATCH net] VSOCK: handle VIRTIO_VSOCK_OP_CREDIT_REQUEST

From: Harshavardhan Unnibhavi <harshanavkis@gmail.com>
To: stefanha@redhat.com, sgarzare@redhat.com, davem@davemloft.net,
	kuba@kernel.org, asias@redhat.com, mst@redhat.com,
	imbrenda@linux.vnet.ibm.com, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Harshavardhan Unnibhavi <harshanavkis@gmail.com>
Subject: [PATCH net] VSOCK: handle VIRTIO_VSOCK_OP_CREDIT_REQUEST
Date: Mon,  2 Aug 2021 19:35:06 +0200	[thread overview]
Message-ID: <20210802173506.2383-1-harshanavkis@gmail.com> (raw)

The original implementation of the virtio-vsock driver does not
handle a VIRTIO_VSOCK_OP_CREDIT_REQUEST as required by the
virtio-vsock specification. The vsock device emulated by
vhost-vsock and the virtio-vsock driver never uses this request,
which was probably why nobody noticed it. However, another
implementation of the device may use this request type.

Hence, this commit introduces a way to handle an explicit credit
request by responding with a corresponding credit update as
required by the virtio-vsock specification.

Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko")

Signed-off-by: Harshavardhan Unnibhavi <harshanavkis@gmail.com>
---
 net/vmw_vsock/virtio_transport_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 169ba8b72a63..081e7ae93cb1 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1079,6 +1079,9 @@ virtio_transport_recv_connected(struct sock *sk,
 		virtio_transport_recv_enqueue(vsk, pkt);
 		sk->sk_data_ready(sk);
 		return err;
+	case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
+		virtio_transport_send_credit_update(vsk);
+		break;
 	case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 		sk->sk_write_space(sk);
 		break;
-- 
2.17.1

