Reducing idle CPU usage of Windows Server 2019 Datacenter Core VM

I'm moving a few installations to Windows Server Datacenter Core 2019 running in KVM VMs on Linux hosts.

My first Windows VM has, when it's idle, a bit more than 32000 VM exits per second, half of them are MSR writes and the other half HLT instructions. For comparison, an idle Linux VM has around 20 per second each.

As the VM has 16 threads, I get some nice round numbers here: each CPU sets a timer and goes to sleep exactly 1000 times per second, so my suspicion (which may be wrong) is that there is a 1kHz timer on every CPU. That causes somewhere around 1-5% of load across all CPUs, and I'd like to reduce that.

Does that timer always exist on Windows, and if so, is there a setting to adjust it? If not, is there a tool to find out why Windows believes such a timer is needed?

Virtual hardware is virtio-net and viostor, an EHCI USB controller with a HID tablet for the mouse interface, PS/2 keyboard and mouse and a QXL graphics card. I have exposed only HPET and Hyper-V timers, but it seems to make no difference if I also offer RTC and PIT:

<domain type='kvm'>
  <name>test-win2019</name>
  <uuid>56f23fbd-9173-4f8e-b63a-59b7eb667fc0</uuid>
  <memory unit='KiB'>16777216</memory>
  <currentMemory unit='KiB'>16777216</currentMemory>
  <memoryBacking>
    <hugepages/>
  </memoryBacking>
  <vcpu placement='static' cpuset='8-15,24-31'>16</vcpu>
  <numatune>
    <memory mode='strict' nodeset='1'/>
  </numatune>
  <os>
    <type arch='x86_64' machine='pc-q35-2.8'>hvm</type>
    <loader readonly='yes' secure='no' type='pflash'>/usr/share/OVMF/OVMF_CODE.fd</loader>
    <nvram template='/usr/share/OVMF/OVMF_VARS.fd'>/var/lib/libvirt/nvram/test-win2019_VARS.fd</nvram>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
    </hyperv>
  </features>
  <cpu mode='custom' match='exact' check='full'>
    <model fallback='forbid'>Skylake-Client-IBRS</model>
    <vendor>Intel</vendor>
    <topology sockets='1' cores='8' threads='2'/>
    <feature policy='require' name='ss'/>
    <feature policy='require' name='hypervisor'/>
    <feature policy='require' name='tsc_adjust'/>
    <feature policy='require' name='umip'/>
    <feature policy='require' name='md-clear'/>
    <feature policy='require' name='ssbd'/>
    <feature policy='require' name='pdpe1gb'/>
    <feature policy='disable' name='mpx'/>
    <feature policy='disable' name='xsavec'/>
    <feature policy='disable' name='xgetbv1'/>
    <numa>
      <cell id='0' cpus='0-15' memory='16777216' unit='KiB'/>
    </numa>
  </cpu>
  <clock offset='localtime'>
    <timer name='hpet' present='yes'/>
    <timer name='hypervclock' present='yes'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <pm>
    <suspend-to-mem enabled='no'/>
    <suspend-to-disk enabled='no'/>
  </pm>
  <devices>
    <emulator>/usr/bin/kvm</emulator>
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source dev='/dev/darine/test-win2019'/>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <boot order='1'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/srv/WindowsServer2019.iso'/>
      <backingStore/>
      <target dev='sda' bus='sata'/>
      <readonly/>
      <boot order='2'/>
      <alias name='sata0-0-0'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/srv/virtio-win_amd64.iso'/>
      <backingStore/>
      <target dev='sdb' bus='sata'/>
      <readonly/>
      <alias name='sata0-0-1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    </disk>
    <controller type='usb' index='0' model='ich9-ehci1'>
      <alias name='usb'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
    </controller>
    <controller type='pci' index='0' model='pcie-root'>
      <alias name='pcie.0'/>
    </controller>
    <controller type='pci' index='1' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='1' port='0x8'/>
      <alias name='pci.1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' multifunction='on'/>
    </controller>
    <controller type='pci' index='2' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='2' port='0x9'/>
      <alias name='pci.2'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <controller type='pci' index='3' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='3' port='0xa'/>
      <alias name='pci.3'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='sata' index='0'>
      <alias name='ide'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
    </controller>
    <interface type='network'>
      <mac address='52:54:00:1e:46:45'/>
      <source network='default' bridge='virbr0'/>
      <target dev='vnet3'/>
      <model type='virtio'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    </interface>
    <input type='tablet' bus='usb'>
      <alias name='input0'/>
      <address type='usb' bus='0' port='1'/>
    </input>
    <input type='mouse' bus='ps2'>
      <alias name='input1'/>
    </input>
    <input type='keyboard' bus='ps2'>
      <alias name='input2'/>
    </input>
    <graphics type='vnc' port='5909' autoport='no' listen='127.0.0.1'>
      <listen type='address' address='127.0.0.1'/>
    </graphics>
    <video>
      <model type='qxl' ram='65536' vram='16384' vgamem='16384' heads='1' primary='yes'/>
      <alias name='video0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='none'/>
  </devices>
  <seclabel type='dynamic' model='apparmor' relabel='yes'>
    <label>libvirt-56f23fbd-9173-4f8e-b63a-59b7eb667fc0</label>
    <imagelabel>libvirt-56f23fbd-9173-4f8e-b63a-59b7eb667fc0</imagelabel>
  </seclabel>
  <seclabel type='dynamic' model='dac' relabel='yes'>
    <label>+64055:+64055</label>
    <imagelabel>+64055:+64055</imagelabel>
  </seclabel>
</domain>