Re: [libvirt] [RFC] Support for CPUID masking
2009/9/2 Jiri Denemark <jdenemar(a)redhat.com>:
Hi,
We need to provide support for CPU ID masking. Xen and VMware ESX are examples
of current hypervisors which support such masking.
[...]
<domain type='xen' id='42'>
...
<features>
<pae/>
<acpi/>
<apic/>
<cpuid>
<mask level='1' register='ebx'>
xxxx:xxxx:0000:1010:xxxx:xxxx:xxxx:xxxx
</mask>
<mask level='1' register='ecx'>
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xx1x:xxxx
</mask>
<mask level='1' register='edx'>
xxx1:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx
</mask>
<mask level='80000001' register='ecx'>
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xx1x
</mask>
<mask level='80000008' register='ecx'>
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xx00:1001
</mask>
</cpuid>
</features>
...
</domain>
I like the proposed mapping for the domain XML, because it's an 1:1
mapping of what VMware uses in the VI API [1] and the VMX config.
Beside that VMware has two more possible values for the CPUID bits: H
and R. Both are used to define how to handle/interpret those bits in
the context of VMotion (migration).
For example the domain XML snippet above maps to this VMX snippet:
cpuid.1.ebx = "XXXXXXXX00001010XXXXXXXXXXXXXXXX"
cpuid.1.ecx = "XXXXXXXXXXXXXXXXXXXXXXXXXX1XXXXX"
cpuid.1.edx = "XXX1XXXXXXXXXXXXXXXXXXXXXXXXXXXX"
cpuid.80000001.ecx = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX1X"
cpuid.80000008.ecx = "XXXXXXXXXXXXXXXXXXXXXXXXXX001001"
Matthias
[1]
http://www.vmware.com/support/developer/vc-sdk/visdk400pubs/ReferenceGuid...