1 files changed, 60 insertions, 43 deletions

diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index ba562d68dc04..588930a0ced1 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -63,6 +63,7 @@ struct virtio_uml_device {
 
 	u8 config_changed_irq:1;
 	uint64_t vq_irq_vq_map;
+	int recv_rc;
 };
 
 struct virtio_uml_vq_info {
@@ -148,14 +149,6 @@ static int vhost_user_recv(struct virtio_uml_device *vu_dev,
 
 	rc = vhost_user_recv_header(fd, msg);
 
-	if (rc == -ECONNRESET && vu_dev->registered) {
-		struct virtio_uml_platform_data *pdata;
-
-		pdata = vu_dev->pdata;
-
-		virtio_break_device(&vu_dev->vdev);
-		schedule_work(&pdata->conn_broken_wk);
-	}
 	if (rc)
 		return rc;
 	size = msg->header.size;
@@ -164,6 +157,21 @@ static int vhost_user_recv(struct virtio_uml_device *vu_dev,
 	return full_read(fd, &msg->payload, size, false);
 }
 
+static void vhost_user_check_reset(struct virtio_uml_device *vu_dev,
+				   int rc)
+{
+	struct virtio_uml_platform_data *pdata = vu_dev->pdata;
+
+	if (rc != -ECONNRESET)
+		return;
+
+	if (!vu_dev->registered)
+		return;
+
+	virtio_break_device(&vu_dev->vdev);
+	schedule_work(&pdata->conn_broken_wk);
+}
+
 static int vhost_user_recv_resp(struct virtio_uml_device *vu_dev,
 				struct vhost_user_msg *msg,
 				size_t max_payload_size)
@@ -171,8 +179,10 @@ static int vhost_user_recv_resp(struct virtio_uml_device *vu_dev,
 	int rc = vhost_user_recv(vu_dev, vu_dev->sock, msg,
 				 max_payload_size, true);
 
-	if (rc)
+	if (rc) {
+		vhost_user_check_reset(vu_dev, rc);
 		return rc;
+	}
 
 	if (msg->header.flags != (VHOST_USER_FLAG_REPLY | VHOST_USER_VERSION))
 		return -EPROTO;
@@ -364,44 +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));
-
-	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 (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);
-
-	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)
@@ -412,7 +426,9 @@ static irqreturn_t vu_req_interrupt(int irq, void *data)
 	if (!um_irq_timetravel_handler_used())
 		ret = vu_req_read_message(vu_dev, NULL);
 
-	if (vu_dev->vq_irq_vq_map) {
+	if (vu_dev->recv_rc) {
+		vhost_user_check_reset(vu_dev, vu_dev->recv_rc);
+	} else if (vu_dev->vq_irq_vq_map) {
 		struct virtqueue *vq;
 
 		virtio_device_for_each_vq((&vu_dev->vdev), vq) {
@@ -945,6 +961,7 @@ static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
 		goto error_create;
 	}
 	vq->priv = info;
+	vq->num_max = num;
 	num = virtqueue_get_vring_size(vq);
 
 	if (vu_dev->protocol_features &