Hello,
tried on a test environment where I have 3.6.0 on single CentOS 7.1 hypervisor configured with SelfHostedEngine
I have a CentOS 7.1 vm running.

On hypervisor I shutdown VM, put maintenance global and shutdown engine VM.
Then
[root@ractor ~]# yum --enablerepo=cr update libvirt*
Loaded plugins: fastestmirror, langpacks
cr                                                                           | 3.4 kB  00:00:00    
cr/7/x86_64/primary_db                                                       | 3.7 MB  00:00:02    
Loading mirror speeds from cached hostfile
 * base: centos.fastbull.org
 * extras: centos.fastbull.org
 * ovirt-3.6: ftp.nluug.nl
 * ovirt-3.6-epel: epel.besthosting.ua
 * updates: centos.copahost.com
Resolving Dependencies
--> Running transaction check
---> Package libvirt-client.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-client.x86_64 0:1.2.17-13.el7_2.2 will be an update
--> Processing Dependency: libsystemd.so.0(LIBSYSTEMD_209)(64bit) for package: libvirt-client-1.2.17-13.el7_2.2.x86_64
--> Processing Dependency: libsystemd.so.0()(64bit) for package: libvirt-client-1.2.17-13.el7_2.2.x86_64
---> Package libvirt-daemon.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-config-nwfilter.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-config-nwfilter.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-interface.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-interface.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-network.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-network.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-nodedev.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-nodedev.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-nwfilter.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-nwfilter.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-qemu.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-qemu.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-secret.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-secret.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-daemon-driver-storage.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-driver-storage.x86_64 0:1.2.17-13.el7_2.2 will be an update
--> Processing Dependency: libdevmapper.so.1.02(DM_1_02_97)(64bit) for package: libvirt-daemon-driver-storage-1.2.17-13.el7_2.2.x86_64
---> Package libvirt-daemon-kvm.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-daemon-kvm.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-lock-sanlock.x86_64 0:1.2.8-16.el7_1.5 will be updated
---> Package libvirt-lock-sanlock.x86_64 0:1.2.17-13.el7_2.2 will be an update
---> Package libvirt-python.x86_64 0:1.2.8-7.el7_1.1 will be updated
---> Package libvirt-python.x86_64 0:1.2.17-2.el7 will be an update
--> Running transaction check
---> Package device-mapper-libs.x86_64 7:1.02.93-3.el7_1.1 will be updated
--> Processing Dependency: device-mapper-libs = 7:1.02.93-3.el7_1.1 for package: 7:device-mapper-1.02.93-3.el7_1.1.x86_64
---> Package device-mapper-libs.x86_64 7:1.02.107-5.el7 will be an update
---> Package systemd-libs.x86_64 0:208-20.el7_1.6 will be updated
--> Processing Dependency: systemd-libs = 208-20.el7_1.6 for package: systemd-208-20.el7_1.6.x86_64
---> Package systemd-libs.x86_64 0:219-19.el7 will be an update
--> Running transaction check
---> Package device-mapper.x86_64 7:1.02.93-3.el7_1.1 will be updated
--> Processing Dependency: device-mapper = 7:1.02.93-3.el7_1.1 for package: 7:device-mapper-event-1.02.93-3.el7_1.1.x86_64
---> Package device-mapper.x86_64 7:1.02.107-5.el7 will be an update
---> Package systemd.x86_64 0:208-20.el7_1.6 will be updated
--> Processing Dependency: systemd = 208-20.el7_1.6 for package: systemd-sysv-208-20.el7_1.6.x86_64
--> Processing Dependency: systemd = 208-20.el7_1.6 for package: systemd-python-208-20.el7_1.6.x86_64
--> Processing Dependency: systemd = 208-20.el7_1.6 for package: libgudev1-208-20.el7_1.6.x86_64
---> Package systemd.x86_64 0:219-19.el7 will be an update
--> Processing Dependency: kmod >= 18-4 for package: systemd-219-19.el7.x86_64
--> Running transaction check
---> Package device-mapper-event.x86_64 7:1.02.93-3.el7_1.1 will be updated
--> Processing Dependency: device-mapper-event = 7:1.02.93-3.el7_1.1 for package: 7:lvm2-libs-2.02.115-3.el7_1.1.x86_64
---> Package device-mapper-event.x86_64 7:1.02.107-5.el7 will be an update
--> Processing Dependency: device-mapper-event-libs = 7:1.02.107-5.el7 for package: 7:device-mapper-event-1.02.107-5.el7.x86_64
---> Package kmod.x86_64 0:14-10.el7 will be updated
---> Package kmod.x86_64 0:20-5.el7 will be an update
---> Package libgudev1.x86_64 0:208-20.el7_1.6 will be updated
---> Package libgudev1.x86_64 0:219-19.el7 will be an update
---> Package systemd-python.x86_64 0:208-20.el7_1.6 will be updated
---> Package systemd-python.x86_64 0:219-19.el7 will be an update
---> Package systemd-sysv.x86_64 0:208-20.el7_1.6 will be updated
---> Package systemd-sysv.x86_64 0:219-19.el7 will be an update
--> Running transaction check
---> Package device-mapper-event-libs.x86_64 7:1.02.93-3.el7_1.1 will be updated
---> Package device-mapper-event-libs.x86_64 7:1.02.107-5.el7 will be an update
---> Package lvm2-libs.x86_64 7:2.02.115-3.el7_1.1 will be updated
--> Processing Dependency: lvm2-libs = 7:2.02.115-3.el7_1.1 for package: 7:lvm2-2.02.115-3.el7_1.1.x86_64
---> Package lvm2-libs.x86_64 7:2.02.130-5.el7 will be an update
--> Running transaction check
---> Package lvm2.x86_64 7:2.02.115-3.el7_1.1 will be updated
---> Package lvm2.x86_64 7:2.02.130-5.el7 will be an update
--> Processing Dependency: device-mapper-persistent-data >= 0.5.5-1 for package: 7:lvm2-2.02.130-5.el7.x86_64
--> Running transaction check
---> Package device-mapper-persistent-data.x86_64 0:0.4.1-2.el7 will be updated
---> Package device-mapper-persistent-data.x86_64 0:0.5.5-1.el7 will be an update
--> Processing Conflict: systemd-219-19.el7.x86_64 conflicts initscripts < 9.49.28-1
--> Restarting Dependency Resolution with new changes.
--> Running transaction check
---> Package initscripts.x86_64 0:9.49.24-1.el7 will be updated
---> Package initscripts.x86_64 0:9.49.30-1.el7 will be an update
--> Processing Conflict: systemd-219-19.el7.x86_64 conflicts dracut < 033-243
--> Restarting Dependency Resolution with new changes.
--> Running transaction check
---> Package dracut.x86_64 0:033-241.el7_1.5 will be updated
--> Processing Dependency: dracut = 033-241.el7_1.5 for package: dracut-config-rescue-033-241.el7_1.5.x86_64
--> Processing Dependency: dracut = 033-241.el7_1.5 for package: dracut-network-033-241.el7_1.5.x86_64
---> Package dracut.x86_64 0:033-360.el7_2 will be an update
--> Running transaction check
---> Package dracut-config-rescue.x86_64 0:033-241.el7_1.5 will be updated
---> Package dracut-config-rescue.x86_64 0:033-360.el7_2 will be an update
---> Package dracut-network.x86_64 0:033-241.el7_1.5 will be updated
---> Package dracut-network.x86_64 0:033-360.el7_2 will be an update
--> Finished Dependency Resolution

Dependencies Resolved

====================================================================================================
 Package                                 Arch           Version                    Repository  Size
====================================================================================================
Updating:
 dracut                                  x86_64         033-360.el7_2              cr         311 k
 initscripts                             x86_64         9.49.30-1.el7              cr         429 k
 libvirt-client                          x86_64         1.2.17-13.el7_2.2          cr         4.3 M
 libvirt-daemon                          x86_64         1.2.17-13.el7_2.2          cr         584 k
 libvirt-daemon-config-nwfilter          x86_64         1.2.17-13.el7_2.2          cr         121 k
 libvirt-daemon-driver-interface         x86_64         1.2.17-13.el7_2.2          cr         161 k
 libvirt-daemon-driver-network           x86_64         1.2.17-13.el7_2.2          cr         301 k
 libvirt-daemon-driver-nodedev           x86_64         1.2.17-13.el7_2.2          cr         160 k
 libvirt-daemon-driver-nwfilter          x86_64         1.2.17-13.el7_2.2          cr         184 k
 libvirt-daemon-driver-qemu              x86_64         1.2.17-13.el7_2.2          cr         569 k
 libvirt-daemon-driver-secret            x86_64         1.2.17-13.el7_2.2          cr         154 k
 libvirt-daemon-driver-storage           x86_64         1.2.17-13.el7_2.2          cr         327 k
 libvirt-daemon-kvm                      x86_64         1.2.17-13.el7_2.2          cr         117 k
 libvirt-lock-sanlock                    x86_64         1.2.17-13.el7_2.2          cr         166 k
 libvirt-python                          x86_64         1.2.17-2.el7               cr         309 k
Updating for dependencies:
 device-mapper                           x86_64         7:1.02.107-5.el7           cr         251 k
 device-mapper-event                     x86_64         7:1.02.107-5.el7           cr         167 k
 device-mapper-event-libs                x86_64         7:1.02.107-5.el7           cr         169 k
 device-mapper-libs                      x86_64         7:1.02.107-5.el7           cr         304 k
 device-mapper-persistent-data           x86_64         0.5.5-1.el7                cr         350 k
 dracut-config-rescue                    x86_64         033-360.el7_2              cr          49 k
 dracut-network                          x86_64         033-360.el7_2              cr          90 k
 kmod                                    x86_64         20-5.el7                   cr         114 k
 libgudev1                               x86_64         219-19.el7                 cr          64 k
 lvm2                                    x86_64         7:2.02.130-5.el7           cr         1.0 M
 lvm2-libs                               x86_64         7:2.02.130-5.el7           cr         872 k
 systemd                                 x86_64         219-19.el7                 cr         5.1 M
 systemd-libs                            x86_64         219-19.el7                 cr         356 k
 systemd-python                          x86_64         219-19.el7                 cr          97 k
 systemd-sysv                            x86_64         219-19.el7                 cr          52 k

Transaction Summary
====================================================================================================
Upgrade  15 Packages (+15 Dependent packages)

Total download size: 17 M
Is this ok [y/d/N]:

Then I reboot my HV, exit from maintenance, connect to engine and start VM.
VM situation
$ free
              total        used        free      shared  buff/cache   available
Mem:        8172900      147356     7875692        8480      149852     7847248
Swap:        839676           0      839676

I set memory from 8192Mb to 10240Mb

I get the same window I got with previous libvirt version.

I select OK (I don't select "Apply later" checkbox)

Inside guest there is no changed memory, but I can see this in /var/log/messages:

Dec  9 23:56:18 racclient1 kernel: init_memory_mapping: [mem 0x240000000-0x2bfffffff]

ANd output of dmesg contains:

[  219.363640] ACPI: \_SB_.MP00: ACPI_NOTIFY_DEVICE_CHECK event
[  219.364248] init_memory_mapping: [mem 0x240000000-0x2bfffffff]
[  219.364253]  [mem 0x240000000-0x2bfffffff] page 2M
[  219.366773]  [ffffea0009000000-ffffea00091fffff] PMD -> [ffff8800b7e00000-ffff8800b7ffffff] on node 0
[  219.368433]  [ffffea0009200000-ffffea00093fffff] PMD -> [ffff880231400000-ffff8802315fffff] on node 0
[  219.369838]  [ffffea0009400000-ffffea00095fffff] PMD -> [ffff880233600000-ffff8802337fffff] on node 0
[  219.371226]  [ffffea0009600000-ffffea00097fffff] PMD -> [ffff880233000000-ffff8802331fffff] on node 0
[  219.372790]  [ffffea0009800000-ffffea00099fffff] PMD -> [ffff880232c00000-ffff880232dfffff] on node 0
[  219.374185]  [ffffea0009a00000-ffffea0009bfffff] PMD -> [ffff880232200000-ffff8802323fffff] on node 0
[  219.377349]  [ffffea0009c00000-ffffea0009ffffff] PMD -> [ffff8800b7400000-ffff8800b77fffff] on node 0
[  219.378716]  [ffffea000a000000-ffffea000a1fffff] PMD -> [ffff8800b7000000-ffff8800b71fffff] on node 0
[  219.380115]  [ffffea000a200000-ffffea000a3fffff] PMD -> [ffff880230c00000-ffff880230dfffff] on node 0
[  219.388147]  [ffffea000a400000-ffffea000abfffff] PMD -> [ffff880227c00000-ffff8802283fffff] on node 0
[  219.389687]  [ffffea000ac00000-ffffea000adfffff] PMD -> [ffff8800b7200000-ffff8800b73fffff] on node 0

I then shutdown the VM and power on it again and I get the changed memory:
$ free
              total        used        free      shared  buff/cache   available
Mem:       10237276      167872     9919656        8480      149748     9891280
Swap:        839676           0      839676

BTW: When I press ok in the gui for memory increase I get these events in webadmin:
Dec 9, 2015 11:56:22 PM
VM racclient1 c71_Disk1_newtemplate disk was updated by admin@internal.
   
Dec 9, 2015 11:56:19 PM
VM racclient1 configuration was updated by admin@internal.
   
Dec 9, 2015 11:56:18 PM 
Hotset memory: changed the amount of memory on VM racclient1 from 8192 to 10240

It doesn't seem as expected, does it?

Gianluca