Relevant logs while the creation fails:

2020-02-17 19:09:09.775 4544 ERROR nova.virt.libvirt.guest [req-0d75d9bd-ff40-4d1a-b80e-1bb029cb0bc2 066d2f8824a744d5b23b783a6a0c8dfe 86289cab83454823800f8119a8dfa16c - 9d7701f7eb2c467ca7d9bded8fa273c4 9d7701f7eb2c467ca7d9bded8fa273c4] Error launching a defined domain with XML: <domain type='kvm'>
  <name>instance-000005e4</name>
  <uuid>49d37209-4f8e-45fb-ba25-816da602f2e3</uuid>
  <metadata>
    <nova:instance xmlns:nova="http://openstack.org/xmlns/libvirt/nova/1.0">
      <nova:package version="17.0.9"/>
      <nova:name>brtlvlts1169fu</nova:name>
      <nova:creationTime>2020-02-17 19:09:03</nova:creationTime>
      <nova:flavor name="8c-32768m">
        <nova:memory>32768</nova:memory>
        <nova:disk>0</nova:disk>
        <nova:swap>0</nova:swap>
        <nova:ephemeral>0</nova:ephemeral>
        <nova:vcpus>8</nova:vcpus>
      </nova:flavor>
      <nova:owner>
        <nova:user uuid="066d2f8824a744d5b23b783a6a0c8dfe">ericsson</nova:user>
        <nova:project uuid="86289cab83454823800f8119a8dfa16c">ocs-prd-pal</nova:project>
      </nova:owner>
      <nova:root type="image" uuid="59adaf6e-aaa1-4b8a-b7f0-36cab9db4e9e"/>
    </nova:instance>
  </metadata>
  <memory unit='KiB'>33554432</memory>
  <currentMemory unit='KiB'>33554432</currentMemory>
  <memoryBacking>
    <hugepages>
      <page size='1048576' unit='KiB' nodeset='0'/>
    </hugepages>
  </memoryBacking>
  <vcpu placement='static'>8</vcpu>
  <cputune>
    <shares>8192</shares>
    <vcpupin vcpu='0' cpuset='0-19,40-59'/>
    <vcpupin vcpu='1' cpuset='0-19,40-59'/>
    <vcpupin vcpu='2' cpuset='0-19,40-59'/>
    <vcpupin vcpu='3' cpuset='0-19,40-59'/>
    <vcpupin vcpu='4' cpuset='0-19,40-59'/>
    <vcpupin vcpu='5' cpuset='0-19,40-59'/>
    <vcpupin vcpu='6' cpuset='0-19,40-59'/>
    <vcpupin vcpu='7' cpuset='0-19,40-59'/>
    <emulatorpin cpuset='0-19,40-59'/>
  </cputune>
  <numatune>
    <memory mode='strict' nodeset='0'/>
    <memnode cellid='0' mode='strict' nodeset='0'/>
  </numatune>
  <sysinfo type='smbios'>
    <system>
      <entry name='manufacturer'>OpenStack Foundation</entry>
      <entry name='product'>OpenStack Nova</entry>
      <entry name='version'>17.0.9</entry>
      <entry name='serial'>6dd001ba-a38a-4bd9-b54e-52ef8ee4a10c</entry>
      <entry name='uuid'>49d37209-4f8e-45fb-ba25-816da602f2e3</entry>
      <entry name='family'>Virtual Machine</entry>
    </system>
  </sysinfo>
  <os>
    <type arch='x86_64' machine='pc-i440fx-bionic'>hvm</type>
    <boot dev='hd'/>
    <smbios mode='sysinfo'/>
  </os>
  <features>
    <acpi/>
    <apic/>
  </features>
  <cpu mode='host-model' check='partial'>
    <model fallback='allow'/>
    <topology sockets='8' cores='1' threads='1'/>
    <numa>
      <cell id='0' cpus='0-7' memory='33554432' unit='KiB' memAccess='shared'/>
    </numa>
  </cpu>
  <clock offset='utc'>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='hpet' present='no'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <devices>
    <emulator>/usr/bin/kvm-spice</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2' cache='none' discard='unmap'/>
      <source file='/var/lib/nova/instances/49d37209-4f8e-45fb-ba25-816da602f2e3/disk'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>
    <controller type='usb' index='0' model='piix3-uhci'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </controller>
    <interface type='vhostuser'>
      <mac address='fa:16:3e:77:31:c4'/>
      <source type='unix' path='/run/libvirt-vhost-user/vhu8e4bd313-3e' mode='server'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <interface type='vhostuser'>
      <mac address='fa:16:3e:b5:90:3d'/>
      <source type='unix' path='/run/libvirt-vhost-user/vhu011b57cc-b5' mode='server'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </interface>
    <serial type='pty'>
      <log file='/var/lib/nova/instances/49d37209-4f8e-45fb-ba25-816da602f2e3/console.log' append='off'/>
      <target type='isa-serial' port='0'>
        <model name='isa-serial'/>
      </target>
    </serial>
    <console type='pty'>
      <log file='/var/lib/nova/instances/49d37209-4f8e-45fb-ba25-816da602f2e3/console.log' append='off'/>
      <target type='serial' port='0'/>
    </console>
    <channel type='spicevmc'>
      <target type='virtio' name='com.redhat.spice.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='1'/>
    </channel>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <graphics type='spice' autoport='yes' listen='0.0.0.0' keymap='en-us'>
      <listen type='address' address='0.0.0.0'/>
    </graphics>
    <video>
      <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1' primary='yes'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='virtio'>
      <stats period='10'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
    </memballoon>
  </devices>
</domain>

[...]

2020-02-17T19:09:05.663074Z qemu-system-x86_64: -chardev socket,id=charnet1,path=/run/libvirt-vhost-user/vhu011b57cc-b5,server: info: QEMU waiting for connection on: disconnected:unix:/run/libvirt-vhost-user/vhu011b57cc-b5,server
2020-02-17T19:09:09.588888Z qemu-system-x86_64: -object memory-backend-file,id=ram-node0,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu/14-instance-000005e4,share=yes,size=34359738368,host-nodes=0,policy=bind: os_mem_prealloc: Insufficient free host memory pages available to allocate guest RAM
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] Traceback (most recent call last):
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2252, in _build_resources
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     yield resources
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2032, in _build_and_run_instance
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     block_device_info=block_device_info)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 3113, in spawn
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     destroy_disks_on_failure=True)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 5622, in _create_domain_and_network
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     destroy_disks_on_failure)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     self.force_reraise()
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     six.reraise(self.type_, self.value, self.tb)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 5591, in _create_domain_and_network
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     post_xml_callback=post_xml_callback)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 5526, in _create_domain
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     guest.launch(pause=pause)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/guest.py", line 144, in launch
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     self._encoded_xml, errors='ignore')
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     self.force_reraise()
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     six.reraise(self.type_, self.value, self.tb)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/guest.py", line 139, in launch
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     return self._domain.createWithFlags(flags)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 186, in doit
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     result = proxy_call(self._autowrap, f, *args, **kwargs)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 144, in proxy_call
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     rv = execute(f, *args, **kwargs)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 125, in execute
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     six.reraise(c, e, tb)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 83, in tworker
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     rv = meth(*args, **kwargs)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]   File "/usr/lib/python2.7/dist-packages/libvirt.py", line 1092, in createWithFlags
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3]     if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self)
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] libvirtError: internal error: process exited while connecting to monitor: 2020-02-17T19:09:05.386869Z qemu-system-x86_64: -chardev socket,id=charnet0,path=/run/libvirt-vhost-user/vhu8e4bd313-3e,server: info: QEMU waiting for connection on: disconnected:unix:/run/libvirt-vhost-user/vhu8e4bd313-3e,server
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] 2020-02-17T19:09:05.663074Z qemu-system-x86_64: -chardev socket,id=charnet1,path=/run/libvirt-vhost-user/vhu011b57cc-b5,server: info: QEMU waiting for connection on: disconnected:unix:/run/libvirt-vhost-user/vhu011b57cc-b5,server
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] 2020-02-17T19:09:09.588888Z qemu-system-x86_64: -object memory-backend-file,id=ram-node0,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu/14-instance-000005e4,share=yes,size=34359738368,host-nodes=0,policy=bind: os_mem_prealloc: Insufficient free host memory pages available to allocate guest RAM
2020-02-17 19:09:10.616 4544 ERROR nova.compute.manager [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] 
2020-02-17 19:09:10.618 4544 INFO nova.compute.manager [req-0d75d9bd-ff40-4d1a-b80e-1bb029cb0bc2 066d2f8824a744d5b23b783a6a0c8dfe 86289cab83454823800f8119a8dfa16c - 9d7701f7eb2c467ca7d9bded8fa273c4 9d7701f7eb2c467ca7d9bded8fa273c4] [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] Terminating instance
2020-02-17 19:09:10.866 4544 INFO nova.virt.libvirt.driver [-] [instance: 49d37209-4f8e-45fb-ba25-816da602f2e3] Instance destroyed successfully.