I tried some steps but didn't reproduce the issue by following steps:

1. Installed one rhel8.2.1 host and installed the packages and win2016 guest used by customer:

# rpm -q qemu-kvm
qemu-kvm-4.2.0-29.module+el8.2.1+9791+7d72b149.6.x86_64
# uname -r
4.18.0-193.29.1.el8_2.x86_64

2. Booted the win2016 guest for a whole night:

/usr/libexec/qemu-kvm \
-name guest=instance-00005f1d,debug-threads=on \
-S \
-machine pc-i440fx-rhel7.6.0,accel=kvm,usb=off,dump-guest-core=on \
-cpu SandyBridge-IBRS,vme=on,f16c=on,rdrand=on,hypervisor=on,arat=on,xsaveopt=on,abm=on \
-m 32768 \
-overcommit mem-lock=off \
-smp 6,sockets=6,dies=1,cores=1,threads=1 \
-uuid 773b0d15-a735-43bb-82cb-fdefcad28ea3 \
-smbios 'type=1,manufacturer=Red Hat,product=OpenStack Compute,version=20.4.1-1.20200917173450.el8ost,serial=773b0d15-a735-43bb-82cb-fdefcad28ea3,uuid=773b0d15-a735-43bb-82cb-fdefcad28ea3,family=Virtual Machine' \
-no-user-config \
-nodefaults \
-rtc base=utc,driftfix=slew \
-global kvm-pit.lost_tick_policy=delay \
-no-hpet \
-no-shutdown \
-boot strict=on \
-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
-blockdev '{"driver":"file","filename":"/home/win2016-64-virtio.raw","aio":"native","node-name":"libvirt-2-storage","cache":{"direct":true,"no-flush":false},"auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-2-format","read-only":false,"cache":{"direct":true,"no-flush":false},"driver":"raw","file":"libvirt-2-storage"}' \
-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=libvirt-2-format,id=virtio-disk0,bootindex=1,write-cache=on,serial=9b2c8658-4b54-409d-93eb-f934a8540ceb \
-netdev tap,id=hostnet0,vhost=on \
-device virtio-net-pci,rx_queue_size=512,host_mtu=9000,netdev=hostnet0,id=net0,mac=00:16:3e:09:55:49,bus=pci.0,addr=0x3 \
-device usb-tablet,id=input0,bus=usb.0,port=1 \
-vnc :0 \
-device cirrus-vga,id=video0,bus=pci.0,addr=0x2 \
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 \
-sandbox on \
-msg timestamp=on -monitor stdio

3. Then changed the guest time backwards/forwards, after that, rebooted the guest.

I ran all our windows timer device cases with the test environment on comment 5 and the same qemu cmd line as customer. 
Still can't reproduce the issue.
Summary: 
Finshed=25, PASS=25

And here is the related code, does anyone have any suggestions on how to reproduce the bug?


 190     /*                                                                           
 191      * if the periodic timer's update is due to period re-configuration,         
 192      * we should count the clock since last interrupt.                           
 193      */                                                                          
 194     if (old_period && period_change) {                                           
 195         int64_t last_periodic_clock, next_periodic_clock;                        
 196                                                                                  
 197         next_periodic_clock = muldiv64(s->next_periodic_time,                    
 198                                 RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND);         
 199         last_periodic_clock = next_periodic_clock - old_period;                  
 200         lost_clock = cur_clock - last_periodic_clock;                            
 201         assert(lost_clock >= 0);                                                                                          
 202     }

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