um: virtio: Implement VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS
Implement in-band notifications that are necessary for running vhost-user devices under externally synchronized time-travel mode (which is in a follow-up patch). This feature makes what usually should be eventfd notifications in-band messages. We'll prefer this feature, under the assumption that only a few (simulation) devices will ever support it, since it's not very efficient. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Johannes Berg
Richard Weinberger
Родитель
4b786e24ca
Коммит
dd9ada5627
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@ -10,9 +10,10 @@
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/* Feature bits */
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#define VHOST_USER_F_PROTOCOL_FEATURES 30
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/* Protocol feature bits */
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#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3
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#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
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#define VHOST_USER_PROTOCOL_F_CONFIG 9
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#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3
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#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
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#define VHOST_USER_PROTOCOL_F_CONFIG 9
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#define VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS 14
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/* Vring state index masks */
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#define VHOST_USER_VRING_INDEX_MASK 0xff
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#define VHOST_USER_VRING_POLL_MASK BIT(8)
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@ -24,7 +25,8 @@
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/* Supported protocol features */
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#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK) | \
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BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
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BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG))
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BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG) | \
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BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS))
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enum vhost_user_request {
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VHOST_USER_GET_FEATURES = 1,
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@ -52,12 +54,14 @@ enum vhost_user_request {
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VHOST_USER_SET_VRING_ENDIAN = 23,
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VHOST_USER_GET_CONFIG = 24,
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VHOST_USER_SET_CONFIG = 25,
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VHOST_USER_VRING_KICK = 35,
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};
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enum vhost_user_slave_request {
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VHOST_USER_SLAVE_IOTLB_MSG = 1,
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VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
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VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
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VHOST_USER_SLAVE_VRING_CALL = 4,
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};
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struct vhost_user_header {
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@ -53,6 +53,7 @@ struct virtio_uml_device {
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struct virtio_device vdev;
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struct platform_device *pdev;
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spinlock_t sock_lock;
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int sock, req_fd;
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u64 features;
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u64 protocol_features;
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@ -189,6 +190,7 @@ static int vhost_user_send(struct virtio_uml_device *vu_dev,
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int *fds, size_t num_fds)
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{
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size_t size = sizeof(msg->header) + msg->header.size;
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unsigned long flags;
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bool request_ack;
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int rc;
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@ -207,24 +209,28 @@ static int vhost_user_send(struct virtio_uml_device *vu_dev,
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if (request_ack)
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msg->header.flags |= VHOST_USER_FLAG_NEED_REPLY;
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spin_lock_irqsave(&vu_dev->sock_lock, flags);
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rc = full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds);
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if (rc < 0)
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return rc;
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goto out;
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if (request_ack) {
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uint64_t status;
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rc = vhost_user_recv_u64(vu_dev, &status);
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if (rc)
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return rc;
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goto out;
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if (status) {
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vu_err(vu_dev, "slave reports error: %llu\n", status);
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return -EIO;
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rc = -EIO;
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goto out;
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}
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}
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return 0;
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out:
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spin_unlock_irqrestore(&vu_dev->sock_lock, flags);
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return rc;
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}
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static int vhost_user_send_no_payload(struct virtio_uml_device *vu_dev,
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@ -324,6 +330,7 @@ static void vhost_user_reply(struct virtio_uml_device *vu_dev,
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static irqreturn_t vu_req_interrupt(int irq, void *data)
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{
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struct virtio_uml_device *vu_dev = data;
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struct virtqueue *vq;
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int response = 1;
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struct {
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struct vhost_user_msg msg;
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@ -343,6 +350,15 @@ static irqreturn_t vu_req_interrupt(int irq, void *data)
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virtio_config_changed(&vu_dev->vdev);
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response = 0;
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break;
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case VHOST_USER_SLAVE_VRING_CALL:
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virtio_device_for_each_vq((&vu_dev->vdev), vq) {
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if (vq->index == msg.msg.payload.vring_state.index) {
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response = 0;
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vring_interrupt(0 /* ignored */, vq);
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break;
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}
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}
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break;
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case VHOST_USER_SLAVE_IOTLB_MSG:
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/* not supported - VIRTIO_F_IOMMU_PLATFORM */
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case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
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@ -684,6 +700,15 @@ static bool vu_notify(struct virtqueue *vq)
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const uint64_t n = 1;
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int rc;
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if (info->kick_fd < 0) {
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struct virtio_uml_device *vu_dev;
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vu_dev = to_virtio_uml_device(vq->vdev);
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return vhost_user_set_vring_state(vu_dev, VHOST_USER_VRING_KICK,
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vq->index, 0) == 0;
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}
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do {
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rc = os_write_file(info->kick_fd, &n, sizeof(n));
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} while (rc == -EINTR);
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@ -749,10 +774,13 @@ static void vu_del_vq(struct virtqueue *vq)
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{
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struct virtio_uml_vq_info *info = vq->priv;
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um_free_irq(VIRTIO_IRQ, vq);
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if (info->call_fd >= 0) {
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um_free_irq(VIRTIO_IRQ, vq);
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os_close_file(info->call_fd);
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}
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os_close_file(info->call_fd);
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os_close_file(info->kick_fd);
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if (info->kick_fd >= 0)
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os_close_file(info->kick_fd);
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vring_del_virtqueue(vq);
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kfree(info);
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@ -782,6 +810,15 @@ static int vu_setup_vq_call_fd(struct virtio_uml_device *vu_dev,
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int call_fds[2];
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int rc;
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/* no call FD needed/desired in this case */
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if (vu_dev->protocol_features &
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BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
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vu_dev->protocol_features &
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BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
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info->call_fd = -1;
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return 0;
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}
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/* Use a pipe for call fd, since SIGIO is not supported for eventfd */
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rc = os_pipe(call_fds, true, true);
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if (rc < 0)
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@ -838,10 +875,15 @@ static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
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vq->priv = info;
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num = virtqueue_get_vring_size(vq);
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rc = os_eventfd(0, 0);
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if (rc < 0)
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goto error_kick;
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info->kick_fd = rc;
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if (vu_dev->protocol_features &
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BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS)) {
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info->kick_fd = -1;
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} else {
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rc = os_eventfd(0, 0);
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if (rc < 0)
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goto error_kick;
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info->kick_fd = rc;
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}
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rc = vu_setup_vq_call_fd(vu_dev, vq);
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if (rc)
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@ -866,10 +908,13 @@ static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
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return vq;
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error_setup:
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um_free_irq(VIRTIO_IRQ, vq);
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os_close_file(info->call_fd);
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if (info->call_fd >= 0) {
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um_free_irq(VIRTIO_IRQ, vq);
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os_close_file(info->call_fd);
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}
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error_call:
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os_close_file(info->kick_fd);
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if (info->kick_fd >= 0)
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os_close_file(info->kick_fd);
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error_kick:
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vring_del_virtqueue(vq);
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error_create:
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@ -908,10 +953,12 @@ static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs,
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list_for_each_entry(vq, &vdev->vqs, list) {
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struct virtio_uml_vq_info *info = vq->priv;
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rc = vhost_user_set_vring_kick(vu_dev, vq->index,
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info->kick_fd);
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if (rc)
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goto error_setup;
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if (info->kick_fd >= 0) {
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rc = vhost_user_set_vring_kick(vu_dev, vq->index,
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info->kick_fd);
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if (rc)
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goto error_setup;
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}
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rc = vhost_user_set_vring_enable(vu_dev, vq->index, true);
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if (rc)
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@ -1008,6 +1055,8 @@ static int virtio_uml_probe(struct platform_device *pdev)
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return rc;
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vu_dev->sock = rc;
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spin_lock_init(&vu_dev->sock_lock);
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rc = vhost_user_init(vu_dev);
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if (rc)
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goto error_init;
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