Problems with HPE Nodes after adding 2nd CPU

This Problem occured on HPE DX380 Gen10, but I thin it will be on other vendors too.

After adding 2nd CPU, the CVM will not boot as PCI devices get newly enumerated: 

[root@AHV1 ~]# virsh list --all

 Id   Name                    State

----------------------------------------

 -    NTNX-CVM   shut off

[root@sAHV1 ~]# virsh start NTNX-CVM

error: Failed to start domain 'NTNX-CVM'

error: Hook script execution failed: internal error: Child process (LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin /etc/libvirt/hooks/qemu NTNX-CVM prepare begin -) unexpected exit status 1: [Errno 2] No such file or directory: '/sys/bus/pci/devices/0000:b1:00.0/driver_override'

To resolve this, look in a not yet expanded Node from the same cluster what "b1:00.0" is:

[root@sAHV2 ~]# lspci

...

b1:00.0 Serial Attached SCSI controller: Adaptec Smart Storage PQI 12G SAS/PCIe 3 (rev 01)

...

then look in your expanded node which address  "Adaptec Smart Storage PQI..." has:

[root@sAHV1 ~]# lspci

....

5c:00.0 Serial Attached SCSI controller: Adaptec Smart Storage PQI 12G SAS/PCIe 3 (rev 01)

....

so you got 5c.00.0

then edit your CVM.xml on your expanded node:

[root@AHV1 ~]# virsh dumpxml NTNX-CVM

OLD:

.....

<video>

      <model type='cirrus' vram='16384' heads='1' primary='yes'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>

    </video>

    <hostdev mode='subsystem' type='pci' managed='yes'>

      <source>

        <address domain='0x0000' bus='0xb1' slot='0x00' function='0x0'/>

      </source>

      <rom bar='off'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>

    </hostdev>

...

NEW:

....

<video>

      <model type='cirrus' vram='16384' heads='1' primary='yes'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>

    </video>

    <hostdev mode='subsystem' type='pci' managed='yes'>

      <source>

        <address domain='0x0000' bus='0x5c' slot='0x00' function='0x0'/>

      </source>

      <rom bar='off'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>

    </hostdev>

....

Then you can start your CVM with:

[root@sAHV1 ~]# virsh start NTNX-CVM

and it will start :-)