417 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			417 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Virtio vsock device
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|  *
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|  * Copyright 2015 Red Hat, Inc.
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|  *
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|  * Authors:
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|  *  Stefan Hajnoczi <stefanha@redhat.com>
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|  *
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|  * This work is licensed under the terms of the GNU GPL, version 2 or
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|  * (at your option) any later version.  See the COPYING file in the
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|  * top-level directory.
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|  */
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| 
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| #include <sys/ioctl.h>
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| #include "qemu/osdep.h"
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| #include "standard-headers/linux/virtio_vsock.h"
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| #include "qapi/error.h"
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| #include "hw/virtio/virtio-bus.h"
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| #include "hw/virtio/virtio-access.h"
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| #include "qemu/error-report.h"
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| #include "hw/virtio/vhost-vsock.h"
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| #include "qemu/iov.h"
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| #include "monitor/monitor.h"
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| 
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| enum {
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|     VHOST_VSOCK_SAVEVM_VERSION = 0,
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| 
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|     VHOST_VSOCK_QUEUE_SIZE = 128,
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| };
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| 
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| static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config)
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| {
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|     VHostVSock *vsock = VHOST_VSOCK(vdev);
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|     struct virtio_vsock_config vsockcfg = {};
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| 
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|     virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid);
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|     memcpy(config, &vsockcfg, sizeof(vsockcfg));
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| }
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| 
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| static int vhost_vsock_set_guest_cid(VHostVSock *vsock)
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| {
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|     const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
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|     int ret;
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| 
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|     if (!vhost_ops->vhost_vsock_set_guest_cid) {
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|         return -ENOSYS;
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|     }
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| 
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|     ret = vhost_ops->vhost_vsock_set_guest_cid(&vsock->vhost_dev,
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|                                                vsock->conf.guest_cid);
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|     if (ret < 0) {
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|         return -errno;
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|     }
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|     return 0;
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| }
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| 
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| static int vhost_vsock_set_running(VHostVSock *vsock, int start)
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| {
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|     const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
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|     int ret;
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| 
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|     if (!vhost_ops->vhost_vsock_set_running) {
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|         return -ENOSYS;
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|     }
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| 
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|     ret = vhost_ops->vhost_vsock_set_running(&vsock->vhost_dev, start);
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|     if (ret < 0) {
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|         return -errno;
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|     }
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|     return 0;
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| }
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| 
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| static void vhost_vsock_start(VirtIODevice *vdev)
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| {
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|     VHostVSock *vsock = VHOST_VSOCK(vdev);
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|     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
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|     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
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|     int ret;
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|     int i;
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| 
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|     if (!k->set_guest_notifiers) {
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|         error_report("binding does not support guest notifiers");
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|         return;
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|     }
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| 
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|     ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev);
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|     if (ret < 0) {
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|         error_report("Error enabling host notifiers: %d", -ret);
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|         return;
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|     }
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| 
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|     ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true);
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|     if (ret < 0) {
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|         error_report("Error binding guest notifier: %d", -ret);
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|         goto err_host_notifiers;
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|     }
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| 
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|     vsock->vhost_dev.acked_features = vdev->guest_features;
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|     ret = vhost_dev_start(&vsock->vhost_dev, vdev);
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|     if (ret < 0) {
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|         error_report("Error starting vhost: %d", -ret);
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|         goto err_guest_notifiers;
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|     }
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| 
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|     ret = vhost_vsock_set_running(vsock, 1);
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|     if (ret < 0) {
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|         error_report("Error starting vhost vsock: %d", -ret);
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|         goto err_dev_start;
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|     }
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| 
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|     /* guest_notifier_mask/pending not used yet, so just unmask
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|      * everything here.  virtio-pci will do the right thing by
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|      * enabling/disabling irqfd.
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|      */
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|     for (i = 0; i < vsock->vhost_dev.nvqs; i++) {
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|         vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false);
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|     }
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| 
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|     return;
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| 
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| err_dev_start:
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|     vhost_dev_stop(&vsock->vhost_dev, vdev);
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| err_guest_notifiers:
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|     k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
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| err_host_notifiers:
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|     vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
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| }
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| 
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| static void vhost_vsock_stop(VirtIODevice *vdev)
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| {
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|     VHostVSock *vsock = VHOST_VSOCK(vdev);
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|     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
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|     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
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|     int ret;
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| 
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|     if (!k->set_guest_notifiers) {
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|         return;
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|     }
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| 
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|     ret = vhost_vsock_set_running(vsock, 0);
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|     if (ret < 0) {
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|         error_report("vhost vsock set running failed: %d", ret);
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|         return;
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|     }
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| 
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|     vhost_dev_stop(&vsock->vhost_dev, vdev);
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| 
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|     ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
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|     if (ret < 0) {
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|         error_report("vhost guest notifier cleanup failed: %d", ret);
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|         return;
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|     }
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| 
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|     vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
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| }
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| 
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| static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
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| {
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|     VHostVSock *vsock = VHOST_VSOCK(vdev);
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|     bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
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| 
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|     if (!vdev->vm_running) {
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|         should_start = false;
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|     }
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| 
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|     if (vsock->vhost_dev.started == should_start) {
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|         return;
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|     }
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| 
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|     if (should_start) {
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|         vhost_vsock_start(vdev);
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|     } else {
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|         vhost_vsock_stop(vdev);
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|     }
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| }
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| 
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| static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
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|                                          uint64_t requested_features,
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|                                          Error **errp)
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| {
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|     /* No feature bits used yet */
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|     return requested_features;
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| }
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| 
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| static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq)
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| {
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|     /* Do nothing */
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| }
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| 
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| static void vhost_vsock_guest_notifier_mask(VirtIODevice *vdev, int idx,
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|                                             bool mask)
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| {
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|     VHostVSock *vsock = VHOST_VSOCK(vdev);
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| 
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|     vhost_virtqueue_mask(&vsock->vhost_dev, vdev, idx, mask);
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| }
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| 
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| static bool vhost_vsock_guest_notifier_pending(VirtIODevice *vdev, int idx)
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| {
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|     VHostVSock *vsock = VHOST_VSOCK(vdev);
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| 
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|     return vhost_virtqueue_pending(&vsock->vhost_dev, idx);
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| }
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| 
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| static void vhost_vsock_send_transport_reset(VHostVSock *vsock)
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| {
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|     VirtQueueElement *elem;
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|     VirtQueue *vq = vsock->event_vq;
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|     struct virtio_vsock_event event = {
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|         .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
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|     };
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| 
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|     elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
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|     if (!elem) {
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|         error_report("vhost-vsock missed transport reset event");
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|         return;
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|     }
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| 
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|     if (elem->out_num) {
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|         error_report("invalid vhost-vsock event virtqueue element with "
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|                      "out buffers");
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|         goto out;
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|     }
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| 
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|     if (iov_from_buf(elem->in_sg, elem->in_num, 0,
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|                      &event, sizeof(event)) != sizeof(event)) {
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|         error_report("vhost-vsock event virtqueue element is too short");
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|         goto out;
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|     }
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| 
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|     virtqueue_push(vq, elem, sizeof(event));
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|     virtio_notify(VIRTIO_DEVICE(vsock), vq);
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| 
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| out:
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|     g_free(elem);
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| }
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| 
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| static void vhost_vsock_post_load_timer_cleanup(VHostVSock *vsock)
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| {
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|     if (!vsock->post_load_timer) {
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|         return;
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|     }
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| 
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|     timer_del(vsock->post_load_timer);
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|     timer_free(vsock->post_load_timer);
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|     vsock->post_load_timer = NULL;
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| }
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| 
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| static void vhost_vsock_post_load_timer_cb(void *opaque)
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| {
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|     VHostVSock *vsock = opaque;
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| 
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|     vhost_vsock_post_load_timer_cleanup(vsock);
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|     vhost_vsock_send_transport_reset(vsock);
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| }
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| 
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| static void vhost_vsock_pre_save(void *opaque)
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| {
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|     VHostVSock *vsock = opaque;
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| 
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|     /* At this point, backend must be stopped, otherwise
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|      * it might keep writing to memory. */
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|     assert(!vsock->vhost_dev.started);
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| }
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| 
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| static int vhost_vsock_post_load(void *opaque, int version_id)
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| {
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|     VHostVSock *vsock = opaque;
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|     VirtIODevice *vdev = VIRTIO_DEVICE(vsock);
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| 
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|     if (virtio_queue_get_addr(vdev, 2)) {
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|         /* Defer transport reset event to a vm clock timer so that virtqueue
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|          * changes happen after migration has completed.
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|          */
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|         assert(!vsock->post_load_timer);
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|         vsock->post_load_timer =
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|             timer_new_ns(QEMU_CLOCK_VIRTUAL,
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|                          vhost_vsock_post_load_timer_cb,
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|                          vsock);
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|         timer_mod(vsock->post_load_timer, 1);
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|     }
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|     return 0;
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| }
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| 
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| static const VMStateDescription vmstate_virtio_vhost_vsock = {
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|     .name = "virtio-vhost_vsock",
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|     .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
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|     .version_id = VHOST_VSOCK_SAVEVM_VERSION,
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|     .fields = (VMStateField[]) {
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|         VMSTATE_VIRTIO_DEVICE,
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|         VMSTATE_END_OF_LIST()
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|     },
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|     .pre_save = vhost_vsock_pre_save,
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|     .post_load = vhost_vsock_post_load,
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| };
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| 
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| static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
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| {
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|     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
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|     VHostVSock *vsock = VHOST_VSOCK(dev);
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|     int vhostfd;
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|     int ret;
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| 
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|     /* Refuse to use reserved CID numbers */
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|     if (vsock->conf.guest_cid <= 2) {
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|         error_setg(errp, "guest-cid property must be greater than 2");
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|         return;
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|     }
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| 
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|     if (vsock->conf.guest_cid > UINT32_MAX) {
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|         error_setg(errp, "guest-cid property must be a 32-bit number");
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|         return;
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|     }
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| 
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|     if (vsock->conf.vhostfd) {
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|         vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp);
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|         if (vhostfd == -1) {
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|             error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
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|             return;
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|         }
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|     } else {
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|         vhostfd = open("/dev/vhost-vsock", O_RDWR);
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|         if (vhostfd < 0) {
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|             error_setg_errno(errp, -errno,
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|                              "vhost-vsock: failed to open vhost device");
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|             return;
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|         }
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|     }
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| 
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|     virtio_init(vdev, "vhost-vsock", VIRTIO_ID_VSOCK,
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|                 sizeof(struct virtio_vsock_config));
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| 
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|     /* Receive and transmit queues belong to vhost */
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|     virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
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|     virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
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| 
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|     /* The event queue belongs to QEMU */
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|     vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
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|                                        vhost_vsock_handle_output);
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| 
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|     vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs);
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|     vsock->vhost_dev.vqs = vsock->vhost_vqs;
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|     ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd,
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|                          VHOST_BACKEND_TYPE_KERNEL, 0);
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|     if (ret < 0) {
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|         error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed");
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|         goto err_virtio;
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|     }
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| 
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|     ret = vhost_vsock_set_guest_cid(vsock);
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|     if (ret < 0) {
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|         error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
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|         goto err_vhost_dev;
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|     }
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| 
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|     vsock->post_load_timer = NULL;
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|     return;
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| 
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| err_vhost_dev:
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|     vhost_dev_cleanup(&vsock->vhost_dev);
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| err_virtio:
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|     virtio_cleanup(vdev);
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|     close(vhostfd);
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|     return;
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| }
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| 
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| static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp)
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| {
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|     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
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|     VHostVSock *vsock = VHOST_VSOCK(dev);
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| 
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|     vhost_vsock_post_load_timer_cleanup(vsock);
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| 
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|     /* This will stop vhost backend if appropriate. */
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|     vhost_vsock_set_status(vdev, 0);
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| 
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|     vhost_dev_cleanup(&vsock->vhost_dev);
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|     virtio_cleanup(vdev);
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| }
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| 
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| static Property vhost_vsock_properties[] = {
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|     DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
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|     DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
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|     DEFINE_PROP_END_OF_LIST(),
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| };
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| 
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| static void vhost_vsock_class_init(ObjectClass *klass, void *data)
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| {
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|     DeviceClass *dc = DEVICE_CLASS(klass);
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|     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
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| 
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|     dc->props = vhost_vsock_properties;
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|     dc->vmsd = &vmstate_virtio_vhost_vsock;
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|     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
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|     vdc->realize = vhost_vsock_device_realize;
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|     vdc->unrealize = vhost_vsock_device_unrealize;
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|     vdc->get_features = vhost_vsock_get_features;
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|     vdc->get_config = vhost_vsock_get_config;
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|     vdc->set_status = vhost_vsock_set_status;
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|     vdc->guest_notifier_mask = vhost_vsock_guest_notifier_mask;
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|     vdc->guest_notifier_pending = vhost_vsock_guest_notifier_pending;
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| }
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| 
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| static const TypeInfo vhost_vsock_info = {
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|     .name = TYPE_VHOST_VSOCK,
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|     .parent = TYPE_VIRTIO_DEVICE,
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|     .instance_size = sizeof(VHostVSock),
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|     .class_init = vhost_vsock_class_init,
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| };
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| 
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| static void vhost_vsock_register_types(void)
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| {
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|     type_register_static(&vhost_vsock_info);
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| }
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| 
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| type_init(vhost_vsock_register_types)
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