我正在运行 Windows 10 虚拟机作为我的日常驱动程序，它运行在 ubuntu 服务器 16.04 之上。 GPU 和 USB 扩展卡直通工作正常，但当来宾播放任何音频时，无论是否为提供 ich9 的虚拟机管理程序，我都会遇到主机 CPU 最大化（显示为“系统”CPU 使用率，但它位于 htop 中的 qemu 下）的情况声卡、直通板载声卡（它位于自己的 IOMMU 组中！）或 GPU 中内置的声卡。
通过的板载声卡内置于Z97芯片组中。
这是虚拟机 xml 文件：
<domain type='kvm' id='1' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
<name>Windowz</name>
<uuid>d7c7a1da-2083-49a0-a968-6f28ca9c914e</uuid>
<memory unit='KiB'>20971520</memory>
<currentMemory unit='KiB'>20971520</currentMemory>
<vcpu placement='static'>4</vcpu>
<resource>
<partition>/machine</partition>
</resource>
<os>
<type arch='x86_64' machine='pc-i440fx-xenial'>hvm</type>
</os>
<features>
<acpi/>
<apic/>
<hyperv>
<relaxed state='on'/>
<vapic state='on'/>
<spinlocks state='on' retries='8191'/>
</hyperv>
</features>
<cpu mode='host-passthrough'>
<topology sockets='1' cores='4' threads='1'/>
</cpu>
<clock offset='localtime'>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='pit' tickpolicy='delay'/>
<timer name='hpet' present='no'/>
<timer name='hypervclock' present='yes'/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<pm>
<suspend-to-mem enabled='no'/>
<suspend-to-disk enabled='no'/>
</pm>
<devices>
<emulator>/usr/bin/qemu-system-x86_64</emulator>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<backingStore/>
<target dev='sda' bus='sata'/>
<readonly/>
<boot order='2'/>
<alias name='sata0-0-0'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<backingStore/>
<target dev='sdb' bus='sata'/>
<readonly/>
<alias name='sata0-0-1'/>
<address type='drive' controller='0' bus='0' target='0' unit='1'/>
</disk>
<disk type='block' device='disk'>
<driver name='qemu' type='raw' cache='none' io='native'/>
<source dev='/dev/sdd'/>
<backingStore/>
<target dev='vdc' bus='virtio'/>
<alias name='virtio-disk2'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0e' function='0x0'/>
</disk>
<disk type='block' device='disk'>
<driver name='qemu' type='raw' cache='none' io='native'/>
<source dev='/dev/nvme0n1'/>
<backingStore/>
<target dev='vdd' bus='virtio'/>
<boot order='1'/>
<alias name='virtio-disk3'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0f' function='0x0'/>
</disk>
<disk type='block' device='disk'>
<driver name='qemu' type='raw' cache='none' io='native'/>
<source dev='/dev/sdb'/>
<backingStore/>
<target dev='vde' bus='virtio'/>
<alias name='virtio-disk4'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
</disk>
<disk type='block' device='disk'>
<driver name='qemu' type='raw' cache='none' io='native'/>
<source dev='/dev/sdc'/>
<backingStore/>
<target dev='vdf' bus='virtio'/>
<alias name='virtio-disk5'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
</disk>
<controller type='pci' index='0' model='pci-root'>
<alias name='pci.0'/>
</controller>
<controller type='sata' index='0'>
<alias name='sata0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
</controller>
<controller type='virtio-serial' index='0'>
<alias name='virtio-serial0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
</controller>
<controller type='usb' index='0' model='nec-xhci'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</controller>
<interface type='user'>
<mac address='52:54:00:5d:ea:ef'/>
<model type='virtio'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
<channel type='spicevmc'>
<target type='virtio' name='com.redhat.spice.0' state='disconnected'/>
<alias name='channel0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
<input type='mouse' bus='ps2'/>
<input type='keyboard' bus='ps2'/>
<graphics type='vnc' port='5900' autoport='no' listen='0.0.0.0'>
<listen type='address' address='0.0.0.0'/>
</graphics>
<sound model='ich9'>
<alias name='sound0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</sound>
<video>
<model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1' primary='yes'/>
<alias name='video0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</video>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x06' slot='0x00' function='0x0'/>
</source>
<alias name='hostdev0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
</hostdev>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x06' slot='0x00' function='0x1'/>
</source>
<alias name='hostdev1'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/>
</hostdev>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x07' slot='0x00' function='0x0'/>
</source>
<alias name='hostdev2'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0d' function='0x0'/>
</hostdev>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x00' slot='0x1b' function='0x0'/>
</source>
<alias name='hostdev3'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x10' function='0x0'/>
</hostdev>
<redirdev bus='usb' type='spicevmc'>
<alias name='redir0'/>
<address type='usb' bus='0' port='1'/>
</redirdev>
<redirdev bus='usb' type='spicevmc'>
<alias name='redir1'/>
<address type='usb' bus='0' port='2'/>
</redirdev>
<memballoon model='virtio'>
<alias name='balloon0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0c' function='0x0'/>
</memballoon>
</devices>
<qemu:commandline>
<qemu:arg value='-redir'/>
<qemu:arg value='tcp:1339::1337'/>
<qemu:arg value='-redir'/>
<qemu:arg value='tcp:3819::3819'/>
<qemu:arg value='-redir'/>
<qemu:arg value='tcp:29176::29176'/>
</qemu:commandline>
</domain>
答案1
设法为遇到同样问题的人找到答案。这篇关于unraid的文章解释了这一切。我从 Ubuntu 16.04 附带的库存版本更新了内核，问题得到解决。
先生们，我有一些好消息。我们已经解决了这个问题。我们必须将合并窗口内核一分为二（不好玩）才能解决这个问题，但我们做到了。它将影响在 Linux 内核的任何 4.3.x 或 4.4.x 分支上运行的 QEMU/KVM 下运行的所有 Windows 10 VM。值得庆幸的是，我们找到了一种方法来解决这个问题，而无需修改内核本身。下一个测试版将解决这个问题。