我将 Ubuntu 17.10 作为在 Windows 7 主机上运行的 Virtualbox 5.2.8 中的来宾。我使用的是 Xorg，而不是 Wayland。这之前一直工作正常，但几天前我重新启动了系统，Xorg 不再找到 virtualbox 显示驱动程序，因此只能使用常规帧缓冲区（这意味着自动调整大小不起作用，它只是使用两个配置的监视器之一）。
我尝试从 CD 映像重新安装来宾添加项，显然成功了，但重新启动后没有任何变化。我似乎确实安装了适当的内核模块，表明dmesg它们正在正确加载：
[ 9.311374] vboxguest: loading out-of-tree module taints kernel.
[ 9.311745] vboxguest: module verification failed: signature and/or required key missing - tainting kernel
[ 9.325936] vgdrvHeartbeatInit: Setting up heartbeat to trigger every 2000 milliseconds
[ 9.326122] input: Unspecified device as /devices/pci0000:00/0000:00:04.0/input/input7
[ 9.327069] vboxguest: misc device minor 55, IRQ 20, I/O port d040, MMIO at 00000000f0000000 (size 0x400000)
[ 9.327072] vboxguest: Successfully loaded version 5.2.8 (interface 0x00010004)
[ 10.199552] MCE: In-kernel MCE decoding enabled.
[ 10.456176] [drm] VRAM 01800000
[ 10.461989] [TTM] Zone kernel: Available graphics memory: 2019822 kiB
[ 10.461991] [TTM] Initializing pool allocator
[ 10.462001] [TTM] Initializing DMA pool allocator
[ 10.486730] fbcon: vboxdrmfb (fb0) is primary device
[ 10.535460] Console: switching to colour frame buffer device 100x37
[ 10.537908] vboxvideo 0000:00:02.0: fb0: vboxdrmfb frame buffer device
[ 10.552475] [drm] Initialized vboxvideo 1.0.0 20130823 for 0000:00:02.0 on minor 0
...
[ 14.148062] vboxsf: Successfully loaded version 5.2.8 (interface 0x00010004)
[ 17.380413] VBoxService 5.2.8 r121009 (verbosity: 0) linux.amd64 (Feb 26 2018 15:59:51) release log
00:00:00.000341 main Log opened 2018-09-15T06:01:13.461172000Z
[ 17.380506] 00:00:00.000496 main OS Product: Linux
[ 17.380570] 00:00:00.000563 main OS Release: 4.13.0-38-generic
[ 17.380640] 00:00:00.000627 main OS Version: #43-Ubuntu SMP Wed Mar 14 15:20:44 UTC 2018
[ 17.380715] 00:00:00.000696 main Executable: /opt/VBoxGuestAdditions-5.2.8/sbin/VBoxService
00:00:00.000697 main Process ID: 538
00:00:00.000698 main Package type: LINUX_64BITS_GENERIC
[ 17.382905] 00:00:00.002833 main 5.2.8 r121009 started. Verbose level = 0
[ 17.395666] 00:00:00.015607 automount vbsvcAutoMountWorker: Shared folder 'E_DRIVE' was mounted to '/media/sf_E_DRIVE'
然而，当我启动 Xorg 时，它抱怨缺少驱动程序：
X.Org X Server 1.19.5
Release Date: 2017-10-12
[ 740.609] X Protocol Version 11, Revision 0
[ 740.609] Build Operating System: Linux 4.4.0-97-generic x86_64 Ubuntu
[ 740.610] Current Operating System: Linux ubuntu17 4.13.0-38-generic #43-Ubuntu SMP Wed Mar 14 15:20:44 UTC 2018 x86_64
[ 740.610] Kernel command line: BOOT_IMAGE=/@/boot/vmlinuz-4.13.0-38-generic root=UUID=b01e5b7f-6cdc-44b6-b718-06a7ecf06177 ro rootflags=subvol=@ splash quiet
[ 740.610] Build Date: 15 October 2017 05:51:19PM
[ 740.610] xorg-server 2:1.19.5-0ubuntu2 (For technical support please see http://www.ubuntu.com/support)
[ 740.610] Current version of pixman: 0.34.0
[ 740.610] Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
[ 740.610] Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
...
[ 740.696] (==) Matched vboxvideo as autoconfigured driver 0
[ 740.696] (==) Matched vboxvideo as autoconfigured driver 1
[ 740.696] (==) Matched modesetting as autoconfigured driver 2
[ 740.696] (==) Matched fbdev as autoconfigured driver 3
[ 740.696] (==) Matched vesa as autoconfigured driver 4
[ 740.697] (==) Assigned the driver to the xf86ConfigLayout
[ 740.697] (II) LoadModule: "vboxvideo"
[ 740.698] (WW) Warning, couldn't open module vboxvideo
[ 740.698] (II) UnloadModule: "vboxvideo"
[ 740.698] (II) Unloading vboxvideo
[ 740.698] (EE) Failed to load module "vboxvideo" (module does not exist, 0)
查看/usr/lib/xorg/modules/drivers，确实没有vboxvideo安装驱动程序模块，这很奇怪，因为它一定是在我上次重新启动时就在那里，因为它一切正常。
这个司机应该来自哪里？ virtualbox 来宾添加安装脚本未安装吗？或者我是否需要从其他地方安装它（请注意，我使用的是 Virtualbox 5.2，而 Ubuntu 使用的 virtualbox 版本是 5.1，因此 Ubuntu 提供的来宾添加功能不适用于该主机，因此不能使用它一个选项）？