[GUIDE] Fun XML Tweaks to try

[Siwat2545]

TLDR: this is a guide I made to tweak unraid kvm libvirt xml so you might like it more

So I have been using unraid for a really long time now and I have lots to share about tweaking xml

NOTE: When your edit your vm using the gui tweak need to be reapply !

 

 

1. Adding your own pc brand and model so that It will show in msinfo

Steps:

               In Edit XML section we will add a smbios to it,

  First add <smbios mode='sysinfo'/> in os section

For example

       From

  <os>
    <type arch='x86_64' machine='pc-i440fx-2.9'>hvm</type>
    <loader readonly='yes' type='pflash'>/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd</loader>
    <nvram>/etc/libvirt/qemu/nvram/3cb86e67-5e75-1fd1-e866-b0c58d28c865_VARS-pure-efi.fd</nvram>
  </os>

        To

  <os>
    <type arch='x86_64' machine='pc-i440fx-2.9'>hvm</type>
    <loader readonly='yes' type='pflash'>/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd</loader>
    <nvram>/etc/libvirt/qemu/nvram/3cb86e67-5e75-1fd1-e866-b0c58d28c865_VARS-pure-efi.fd</nvram>
    <smbios mode='sysinfo'/>
  </os>

 

Then add the info you want

after cpu tune section add the following text (Replace [xxxx] with your own text) Not all is required

<sysinfo type='smbios'>
  <bios>
    <entry name='vendor'>[Bios Brand]</entry>
  </bios>
  <system>
    <entry name='manufacturer'>[System Manufacturer]</entry>
    <entry name='product'>[System Name]r</entry>
    <entry name='version'>[System version]</entry>
  </system>
  <baseBoard>
    <entry name='manufacturer'>[Mainboard Manufacturer]</entry>
    <entry name='product'>[Mainboard Name]</entry>
    <entry name='version'>[System Version]</entry>
    <entry name='serial'>[Mainboard Serial]</entry>
  </baseBoard>
  <chassis>
    <entry name='manufacturer'>[Case Manufacturer]</entry>
    <entry name='version'>[Case Versiom]</entry>
    <entry name='serial'>[Case Serial]</entry>
    <entry name='asset'>[Case assest code]</entry>
    <entry name='sku'>[Case sku]</entry>
  </chassis>
</sysinfo>

2. Change Number of core cpus or thread (No performance improvement)

  <cpu mode='host-passthrough' check='none'>
    <topology sockets='[Number of CPUs]' cores='[Number of Cores]' threads='[Number of Threads]'/>
  </cpu>

NOTE: Number of CPUs * Number of Cores * Number of Threads    must be equal to the number of core you assigned to the VM

3. Change the CPU model

    Change <cpu mode='host-passthrough' check='none'> to <cpu match='exact'>

     After that add  <model fallback='allow'>core2duo</model>

For example

<cpu match='exact'>
  <model fallback='allow'>[Insert the model you want here]</model>
  <topology sockets='1' cores='2' threads='1'/>
</cpu>

List of avaliable model

 - n270

 - athlon

 - pentium3

 - pentium2

 - pentium

 - 486

 - coreduo

 - core2duo

 - kvm32

 - qemu32

 - kvm64

 - qemu64

 - phenom

 - Nehalem

 - Penryn

 - Conroe

 - Opteron_G1

 - Opteron_G2

 - Opteron_G3

4. Change the Ethernet Model (Fix Linux or Windows not detecting the ethernet adapter)

change model in network adapter hostdev xml

<interface type='bridge'>
      <mac address='xx:xx:xx:xx:xx:xx'/>
      <source bridge='br(x)'/>
      <model type='[The Model you want]'/>
      <address type='pci' domain='yxyyyy' bus='yxyy' slot='yxyy' function='yxy'/>
    </interface>

List of avaliable model

 - e1000 (1000Base)

 - ne2k_pci (10 Base-T)

 - pcnet (100 Base-T)

 - rtl8139 (100 Base-T)

 - virtio (10G Base-T)

Edited March 15, 2018 by Siwat2545