What were you trying to do that didn't work?
verify dommemstat show right disk cache

Please provide the package NVR for which the bug is seen:
64k Host name:   AWS Graviton4
64k Host Kernel: 6.12.0-89.el10.aarch64+64k
QEMU:  qemu-kvm-10.0.0-6.el10

libvirt_version': '11.3.0'
edk2: edk2-aarch64-20250523-1.el10.noarch
64k Guest Kernel: 6.12.0-77.670_1791517415.el10.aarch64

64k log: 
http://10.0.136.47/meghana/LIBVIRTARM-464/grav4_64k/test-results/05-type_specific.io-github-autotest-libvirt.memory_misc.dommemstat.disk_caches/

How reproducible is this bug?:
100%

Steps to reproduce
1. . prepare a guest with memballoon and set stats period

1. virsh dumpxml avocado-vt-vm1
   ...
       <memballoon model='virtio'>
         <stats period='1'/>
         <alias name='balloon0'/>
         <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
       </memballoon>

2. use dommemstat command to get disk caches:

1. virsh dommemstat avocado-vt-vm1

actual 1024000
swap_in 0
swap_out 0
major_fault 1030
minor_fault 1379325
unused 398668
available 815476
usable 534064
last_update 1559112601
disk_caches 238180
rss 739004

3. verify disk caches value in guest:

IN GUEST:

1. cat /proc/meminfo
   MemTotal: 815476 kB
   MemFree: 398712 kB
   MemAvailable: 534108 kB
   Buffers: 3164 kB
   Cached: 235016 kB
   SwapCached: 0 kB
   ...
   Expected Output:
   from kernel commit: Buffers + Cached + SwapCached = disk_caches

Observed Output:

[root@ip-10-116-1-142 ~]# virsh dommemstat avocado-vt-vm1
actual 4194304
swap_in 0
swap_out 0
major_fault 776
minor_fault 122085
unused 3797784
available 4038148
usable 3914960
last_update 1751610368
rss 1825536[root@ip-10-116-1-142 ~]#

disk_caches is not available.