17.4.

# virsh dominfo testguest
Max memory:     2097152 KiB
Used memory:    2097152 KiB

# virsh dominfo testguest
Max memory:     2097152 KiB
Used memory:    2097152 KiB

# virt-xml testguest --edit --memory memory=4096,currentMemory=4096
Domain 'testguest' defined successfully.
Changes will take effect after the domain is fully powered off.

# virsh setmem testguest --current 2048

# virsh dominfo testguest
Max memory:     4194304 KiB
Used memory:    2097152 KiB

 # virsh domstats --balloon testguest
Domain: 'testguest'
  balloon.current=365624
  balloon.maximum=4194304
  balloon.swap_in=0
  balloon.swap_out=0
  balloon.major_fault=306
  balloon.minor_fault=156117
  balloon.unused=3834448
  balloon.available=4035008
  balloon.usable=3746340
  balloon.last-update=1587971682
  balloon.disk_caches=75444
  balloon.hugetlb_pgalloc=0
  balloon.hugetlb_pgfail=0
  balloon.rss=1005456

# virsh edit testguest

<memoryBacking>
  <hugepages>
    <page size='1' unit='GiB'/>
  </hugepages>
</memoryBacking>

# cat /proc/meminfo | grep Huge

HugePages_Total:    4
HugePages_Free:     2
HugePages_Rsvd:     1
Hugepagesize:       1024000 kB