libvirt users - Jul 2022 - Why can not get the expected cpu topology after setting the maxcpu in xml?

Hello all,

I hit a issue that I'm not able to see the expected cpu topology in VM after
setting the maxcpu arrtribute in domain.

the xml look like below:
<vcpu placement='static' current='4'>8</vcpu>
  <cpu mode='host-passthrough' check='none'
migratable='on'>
    <topology sockets='2' dies='1' cores='4'
threads='1'/>
  </cpu>

I notice that the cpu topoloy looked like below capture output from
'lscpu' tool which is totally different with my setting.

CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    1
Core(s) per socket:    4
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 63
Model name:            Intel(R) Xeon(R) CPU E5-2699 v3 @ 2.30GHz

Besides i found it looked correct if i relpace 'vcpu' line with
"<vcpu placement='static'>8</vcpu>" that remove
maxcpu value.

Could you give me some information? Any comments are appreciated.

Thanks
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