1 files changed, 37 insertions, 34 deletions

diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index e719af8bdf56..588930a0ced1 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -374,45 +374,48 @@ static irqreturn_t vu_req_read_message(struct virtio_uml_device *vu_dev,
 		u8 extra_payload[512];
 	} msg;
 	int rc;
+	irqreturn_t irq_rc = IRQ_NONE;
 
-	rc = vhost_user_recv_req(vu_dev, &msg.msg,
-				 sizeof(msg.msg.payload) +
-				 sizeof(msg.extra_payload));
-
-	vu_dev->recv_rc = rc;
-	if (rc)
-		return IRQ_NONE;
-
-	switch (msg.msg.header.request) {
-	case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG:
-		vu_dev->config_changed_irq = true;
-		response = 0;
-		break;
-	case VHOST_USER_SLAVE_VRING_CALL:
-		virtio_device_for_each_vq((&vu_dev->vdev), vq) {
-			if (vq->index == msg.msg.payload.vring_state.index) {
-				response = 0;
-				vu_dev->vq_irq_vq_map |= BIT_ULL(vq->index);
-				break;
+	while (1) {
+		rc = vhost_user_recv_req(vu_dev, &msg.msg,
+					 sizeof(msg.msg.payload) +
+					 sizeof(msg.extra_payload));
+		if (rc)
+			break;
+
+		switch (msg.msg.header.request) {
+		case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG:
+			vu_dev->config_changed_irq = true;
+			response = 0;
+			break;
+		case VHOST_USER_SLAVE_VRING_CALL:
+			virtio_device_for_each_vq((&vu_dev->vdev), vq) {
+				if (vq->index == msg.msg.payload.vring_state.index) {
+					response = 0;
+					vu_dev->vq_irq_vq_map |= BIT_ULL(vq->index);
+					break;
+				}
 			}
+			break;
+		case VHOST_USER_SLAVE_IOTLB_MSG:
+			/* not supported - VIRTIO_F_ACCESS_PLATFORM */
+		case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
+			/* not supported - VHOST_USER_PROTOCOL_F_HOST_NOTIFIER */
+		default:
+			vu_err(vu_dev, "unexpected slave request %d\n",
+			       msg.msg.header.request);
 		}
-		break;
-	case VHOST_USER_SLAVE_IOTLB_MSG:
-		/* not supported - VIRTIO_F_ACCESS_PLATFORM */
-	case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
-		/* not supported - VHOST_USER_PROTOCOL_F_HOST_NOTIFIER */
-	default:
-		vu_err(vu_dev, "unexpected slave request %d\n",
-		       msg.msg.header.request);
-	}
-
-	if (ev && !vu_dev->suspended)
-		time_travel_add_irq_event(ev);
 
-	if (msg.msg.header.flags & VHOST_USER_FLAG_NEED_REPLY)
-		vhost_user_reply(vu_dev, &msg.msg, response);
+		if (ev && !vu_dev->suspended)
+			time_travel_add_irq_event(ev);
 
-	return IRQ_HANDLED;
+		if (msg.msg.header.flags & VHOST_USER_FLAG_NEED_REPLY)
+			vhost_user_reply(vu_dev, &msg.msg, response);
+		irq_rc = IRQ_HANDLED;
+	};
+	/* mask EAGAIN as we try non-blocking read until socket is empty */
+	vu_dev->recv_rc = (rc == -EAGAIN) ? 0 : rc;
+	return irq_rc;
 }
 
 static irqreturn_t vu_req_interrupt(int irq, void *data)