[vioscsi] - Windows 10 "Optimize drive"/Trim/Discard causes all data to be rewritten

[milsav92]

I'm using the virtio-win-0.1.208.iso version of vioscsi on Windows 10 x64 21H1 in a libvirt+KVM+QEMU combo.

Running the trim command causes a high cpu load, runs for an absurd time (bare metal installation runs for ~5 sec vs 10-15 min for the vioscsi version) and it causes all the data to be rewritten again instead of just trimming the drive (can be seen in iotop, iostat and in S.M.A.R.T. Lifetime writes) which is less than ideal for a ssd.
Linux guests do not suffer from this problem.

Passing the device.scsi0-0-0-0.rotation_rate=1 aka. SSD emulation argument to QEMU doesn't have an impact.

A similar problem can be seen here https://forum.level1techs.com/t/win10-optimize-drives-makes-underlying-sparse-storage-grow-not-shrink/172803

Is this perhaps a Windows defrag.exe issue?

[milsav92]

Forgot to say that when defrag.exe is running it uses one core and 2,170MB of memory, and Task Manager shows that there is a lot of disk write activity.

Resource Monitor shows a lot of write activity to C:$LogFile by defragsvc and Registry.

[vrozenfe]

@milsav92

Thanks a lot for reporting this issue.
Can you please post the qemu command line along with qemu version?
Hopefully this this information will help us to reproduce the problem.

Just for the record, virtio-scsi driver for Windows is fully relying on qemu
code and doesn't intercept (unlike virtio-blk viostor driver) SCSIOP_UNMAP
request. In this term it is quite interesting if virtio-blk has the same problem.

Best,
Vadim.

[milsav92]

PC:

QEMU emulator version 6.1.0 (openSUSE Tumbleweed)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

/usr/bin/qemu-system-x86_64 -name guest=win10,debug-threads=on -S -object {"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain-12-win10/master-key.aes"} -machine pc-q35-6.1,accel=kvm,usb=off,vmport=off,dump-guest-core=off,memory-backend=pc.ram -cpu EPYC-Milan,x2apic=on,tsc-deadline=on,hypervisor=on,tsc-adjust=on,vaes=on,vpclmulqdq=on,spec-ctrl=on,stibp=on,arch-capabilities=on,ssbd=on,cmp-legacy=on,virt-ssbd=on,rdctl-no=on,skip-l1dfl-vmentry=on,mds-no=on,pschange-mc-no=on,pcid=off,hv-time,hv-relaxed,hv-vapic,hv-spinlocks=0x1fff -m 16384 -object {"qom-type":"memory-backend-ram","id":"pc.ram","size":17179869184} -overcommit mem-lock=off -smp 8,sockets=8,cores=1,threads=1 -uuid 3f5b5ce9-4fab-40b9-bee9-84bb2f8c26c0 -no-user-config -nodefaults -chardev socket,id=charmonitor,fd=31,server=on,wait=off -mon chardev=charmonitor,id=monitor,mode=control -rtc base=localtime,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -device pcie-root-port,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x2 -device pcie-root-port,port=0x11,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 -device pcie-root-port,port=0x12,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 -device pcie-root-port,port=0x13,chassis=4,id=pci.4,bus=pcie.0,addr=0x2.0x3 -device pcie-root-port,port=0x14,chassis=5,id=pci.5,bus=pcie.0,addr=0x2.0x4 -device pcie-root-port,port=0x15,chassis=6,id=pci.6,bus=pcie.0,addr=0x2.0x5 -device qemu-xhci,p2=15,p3=15,id=usb,bus=pci.2,addr=0x0 -device virtio-scsi-pci,id=scsi0,bus=pci.3,addr=0x0 -device virtio-serial-pci,id=virtio-serial0,bus=pci.4,addr=0x0 -blockdev {"driver":"file","filename":"/mnt/vms/images/win10.img","node-name":"libvirt-3-storage","cache":{"direct":true,"no-flush":false},"auto-read-only":true,"discard":"unmap"} -blockdev {"node-name":"libvirt-3-format","read-only":false,"discard":"unmap","detect-zeroes":"unmap","cache":{"direct":true,"no-flush":false},"driver":"raw","file":"libvirt-3-storage"} -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,device_id=drive-scsi0-0-0-0,drive=libvirt-3-format,id=scsi0-0-0-0,bootindex=1,write-cache=on -blockdev {"driver":"file","filename":"/mnt/vms/images/win10-1.img","node-name":"libvirt-2-storage","cache":{"direct":false,"no-flush":false},"auto-read-only":true,"discard":"unmap"} -blockdev {"node-name":"libvirt-2-format","read-only":false,"discard":"unmap","detect-zeroes":"unmap","cache":{"direct":false,"no-flush":false},"driver":"raw","file":"libvirt-2-storage"} -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=2,device_id=drive-scsi0-0-0-2,drive=libvirt-2-format,id=scsi0-0-0-2,write-cache=on -device ide-cd,bus=ide.1,id=sata0-0-1 -netdev tap,fd=33,id=hostnet0 -device e1000e,netdev=hostnet0,id=net0,mac=52:54:00:70:cc:72,bus=pci.1,addr=0x0 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev spicevmc,id=charchannel0,name=vdagent -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0 -device usb-tablet,id=input0,bus=usb.0,port=1 -audiodev id=audio1,driver=spice -spice port=5900,addr=127.0.0.1,disable-ticketing=on,image-compression=off,seamless-migration=on -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pcie.0,addr=0x1 -device ich9-intel-hda,id=sound0,bus=pcie.0,addr=0x1b -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0,audiodev=audio1 -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0,bus=usb.0,port=2 -chardev spicevmc,id=charredir1,name=usbredir -device usb-redir,chardev=charredir1,id=redir1,bus=usb.0,port=3 -device virtio-balloon-pci,id=balloon0,bus=pci.5,addr=0x0 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny -msg timestamp=on

[milsav92]

Proxmox:

QEMU emulator version 6.0.0 (pve-qemu-kvm_6.0.0)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

/usr/bin/kvm -id 100 -name win10 -no-shutdown -chardev socket,id=qmp,path=/var/run/qemu-server/100.qmp,server=on,wait=off -mon chardev=qmp,mode=control -chardev socket,id=qmp-event,path=/var/run/qmeventd.sock,reconnect=5 -mon chardev=qmp-event,mode=control -pidfile /var/run/qemu-server/100.pid -daemonize -smbios type=1,uuid=f0085f4a-19a2-411a-8934-0452afcb16b0 -smp 2,sockets=1,cores=2,maxcpus=2 -nodefaults -boot menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg -vnc unix:/var/run/qemu-server/100.vnc,password=on -no-hpet -cpu host,hv_ipi,hv_relaxed,hv_reset,hv_runtime,hv_spinlocks=0x1fff,hv_stimer,hv_synic,hv_time,hv_vapic,hv_vpindex,+kvm_pv_eoi,+kvm_pv_unhalt -m 8192 -object iothread,id=iothread-virtioscsi0 -object iothread,id=iothread-virtioscsi1 -readconfig /usr/share/qemu-server/pve-q35-4.0.cfg -device vmgenid,guid=96814a7f-f7ea-470a-894a-500177c6bf00 -device qxl-vga,id=vga,bus=pcie.0,addr=0x1 -chardev socket,path=/var/run/qemu-server/100.qga,server=on,wait=off,id=qga0 -device virtio-serial,id=qga0,bus=pci.0,addr=0x8 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0 -object rng-random,filename=/dev/urandom,id=rng0 -device virtio-rng-pci,rng=rng0,max-bytes=1024,period=1000,bus=pci.1,addr=0x1d -device virtio-serial,id=spice,bus=pci.0,addr=0x9 -chardev spicevmc,id=vdagent,name=vdagent -device virtserialport,chardev=vdagent,name=com.redhat.spice.0 -spice tls-port=61000,addr=127.0.0.1,tls-ciphers=HIGH,seamless-migration=on -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -iscsi initiator-name=iqn.1993-08.org.debian:01:22d334eb194 -drive if=none,id=drive-ide2,media=cdrom,aio=io_uring -device ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=101 -device virtio-scsi-pci,id=virtioscsi0,bus=pci.3,addr=0x1,iothread=iothread-virtioscsi0 -drive file=/images/100/vm-100-disk-0.qcow2,if=none,id=drive-scsi0,cache=none,werror=stop,discard=on,format=qcow2,aio=io_uring,detect-zeroes=unmap -device scsi-hd,bus=virtioscsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0,id=scsi0,bootindex=100 -device virtio-scsi-pci,id=virtioscsi1,bus=pci.3,addr=0x2,iothread=iothread-virtioscsi1 -drive file=/images/100/vm-100-disk-1.qcow2,if=none,id=drive-scsi1,cache=writeback,werror=stop,discard=on,format=qcow2,aio=io_uring,detect-zeroes=unmap -device scsi-hd,bus=virtioscsi1.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi1,id=scsi1 -netdev type=tap,id=net0,ifname=tap100i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on -device virtio-net-pci,mac=DE:3A:FE:C8:D1:B5,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=102 -rtc driftfix=slew,base=localtime -machine type=pc-q35-6.0+pve0 -global kvm-pit.lost_tick_policy=discard

[milsav92]

Configurations:

• PC - libvirt:
  <domain type="kvm"> <name>win10</name> <uuid>3f5b5ce9-4fab-40b9-bee9-84bb2f8c26c0</uuid> <metadata> <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0"> <libosinfo:os id="http://microsoft.com/win/10"/> </libosinfo:libosinfo> </metadata> <memory unit="KiB">16777216</memory> <currentMemory unit="KiB">16777216</currentMemory> <vcpu placement="static">8</vcpu> <os> <type arch="x86_64" machine="pc-q35-6.1">hvm</type> <boot dev="hd"/> </os> <features> <acpi/> <apic/> <hyperv> <relaxed state="on"/> <vapic state="on"/> <spinlocks state="on" retries="8191"/> </hyperv> <vmport state="off"/> </features> <cpu mode="host-model" check="partial"/> <clock offset="localtime"> <timer name="rtc" tickpolicy="catchup"/> <timer name="pit" tickpolicy="delay"/> <timer name="hpet" present="no"/> <timer name="hypervclock" present="yes"/> </clock> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <pm> <suspend-to-mem enabled="no"/> <suspend-to-disk enabled="no"/> </pm> <devices> <emulator>/usr/bin/qemu-system-x86_64</emulator> <disk type="file" device="disk"> <driver name="qemu" type="raw" cache="none" discard="unmap" detect_zeroes="unmap"/> <source file="/mnt/vms/images/win10.img"/> <target dev="sda" bus="scsi"/> <address type="drive" controller="0" bus="0" target="0" unit="0"/> </disk> <disk type="file" device="disk"> <driver name="qemu" type="raw" cache="writeback" discard="unmap" detect_zeroes="unmap"/> <source file="/mnt/vms/images/win10-1.img"/> <target dev="sdc" bus="scsi"/> <address type="drive" controller="0" bus="0" target="0" unit="2"/> </disk> <disk type="file" device="cdrom"> <driver name="qemu" type="raw"/> <target dev="sdb" bus="sata"/> <readonly/> <address type="drive" controller="0" bus="0" target="0" unit="1"/> </disk> <controller type="usb" index="0" model="qemu-xhci" ports="15"> <address type="pci" domain="0x0000" bus="0x02" slot="0x00" function="0x0"/> </controller> <controller type="scsi" index="0" model="virtio-scsi"> <address type="pci" domain="0x0000" bus="0x03" slot="0x00" function="0x0"/> </controller> <controller type="sata" index="0"> <address type="pci" domain="0x0000" bus="0x00" slot="0x1f" function="0x2"/> </controller> <controller type="pci" index="0" model="pcie-root"/> <controller type="pci" index="1" model="pcie-root-port"> <model name="pcie-root-port"/> <target chassis="1" port="0x10"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x0" multifunction="on"/> </controller> <controller type="pci" index="2" model="pcie-root-port"> <model name="pcie-root-port"/> <target chassis="2" port="0x11"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x1"/> </controller> <controller type="pci" index="3" model="pcie-root-port"> <model name="pcie-root-port"/> <target chassis="3" port="0x12"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x2"/> </controller> <controller type="pci" index="4" model="pcie-root-port"> <model name="pcie-root-port"/> <target chassis="4" port="0x13"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x3"/> </controller> <controller type="pci" index="5" model="pcie-root-port"> <model name="pcie-root-port"/> <target chassis="5" port="0x14"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x4"/> </controller> <controller type="pci" index="6" model="pcie-root-port"> <model name="pcie-root-port"/> <target chassis="6" port="0x15"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x5"/> </controller> <controller type="virtio-serial" index="0"> <address type="pci" domain="0x0000" bus="0x04" slot="0x00" function="0x0"/> </controller> <interface type="network"> <mac address="52:54:00:70:cc:72"/> <source network="default"/> <model type="e1000e"/> <address type="pci" domain="0x0000" bus="0x01" slot="0x00" function="0x0"/> </interface> <serial type="pty"> <target type="isa-serial" port="0"> <model name="isa-serial"/> </target> </serial> <console type="pty"> <target type="serial" port="0"/> </console> <channel type="spicevmc"> <target type="virtio" name="com.redhat.spice.0"/> <address type="virtio-serial" controller="0" bus="0" port="1"/> </channel> <input type="tablet" bus="usb"> <address type="usb" bus="0" port="1"/> </input> <input type="mouse" bus="ps2"/> <input type="keyboard" bus="ps2"/> <graphics type="spice" autoport="yes"> <listen type="address"/> <image compression="off"/> </graphics> <sound model="ich9"> <address type="pci" domain="0x0000" bus="0x00" slot="0x1b" function="0x0"/> </sound> <audio id="1" type="spice"/> <video> <model type="qxl" ram="65536" vram="65536" vgamem="16384" heads="1" primary="yes"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x01" function="0x0"/> </video> <redirdev bus="usb" type="spicevmc"> <address type="usb" bus="0" port="2"/> </redirdev> <redirdev bus="usb" type="spicevmc"> <address type="usb" bus="0" port="3"/> </redirdev> <memballoon model="virtio"> <address type="pci" domain="0x0000" bus="0x05" slot="0x00" function="0x0"/> </memballoon> </devices> </domain>

• Proxmox:
  agent: 1
  boot: order=scsi0;ide2;net0
  cores: 2
  cpu: host
  ide2: none,media=cdrom
  machine: pc-q35-6.0
  memory: 8192
  name: win10
  net0: virtio=DE:3A:FE:C8:D1:B5,bridge=vmbr0,firewall=1
  numa: 0
  ostype: win10
  protection: 1
  rng0: source=/dev/urandom
  scsi0: vms:100/vm-100-disk-0.qcow2,cache=none,discard=on,iothread=1,replicate=0,size=64G,werror=stop
  scsi1: vms:100/vm-100-disk-1.qcow2,cache=writeback,discard=on,iothread=1,replicate=0,size=16G,werror=stop
  scsihw: virtio-scsi-single
  smbios1: uuid=f0085f4a-19a2-411a-8934-0452afcb16b0
  sockets: 1
  vga: qxl
  vmgenid: 96814a7f-f7ea-470a-894a-500177c6bf00

[vrozenfe]

I will ask QE to reproduce and analyse this issue.
Thanks,
Vadim.

[milsav92]

It seems to be a defrag problem, Win8.1 doesn't show the same symptoms.

Win 8.1

• SMART before defrag

241 Lifetime_Writes_GiB     0x0032   000   000   000    Old_age   Always       -       7813
242 Lifetime_Reads_GiB      0x0032   000   000   000    Old_age   Always       -       11058

• Defrag
  Pay attention to the Retrim: block

PS C:\Windows\system32> defrag e: /u /v /h /o
Microsoft Drive Optimizer
Copyright (c) 2013 Microsoft Corp.

Invoking slab consolidation on SCSI (E:)...

        Slab Analysis:  100% complete.
        Retrim:  100% complete.

        Slab consolidation was skipped because there were few evictable slabs.


The operation completed successfully.

Post Defragmentation Report:

        Volume Information:
                Volume size                 = 19.99 GB
                Cluster size                = 4 KB
                Used space                  = 5.14 GB
                Free space                  = 14.84 GB

        Slab Consolidation:
                Space efficiency            = 100%
                Potential purgable slabs    = 0
                Slabs pinned unmovable      = 0
                Successfully purged slabs   = 0
                Recovered space             = 0 bytes

        Retrim:
                Backed allocations          = 19
                Allocations trimmed         = 15
                Total space trimmed         = 12.11 GB

• SMART after defrag

241 Lifetime_Writes_GiB     0x0032   000   000   000    Old_age   Always       -       7813
242 Lifetime_Reads_GiB      0x0032   000   000   000    Old_age   Always       -       11058

• Defrag runtime

PS C:\Windows\system32> Measure-Command { defrag e: /h /o }


Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 0
Milliseconds      : 665
Ticks             : 6658888
TotalDays         : 7.7070462962963E-06
TotalHours        : 0.000184969111111111
TotalMinutes      : 0.0110981466666667
TotalSeconds      : 0.6658888
TotalMilliseconds : 665.8888

• iostat

root@PC:~> iostat -mh -d 60 sda4
Linux 5.14.11-2-default (PC)       10/25/2021      _x86_64_        (32 CPU)

      tps    MB_read/s    MB_wrtn/s    MB_dscd/s    MB_read    MB_wrtn    MB_dscd Device
     1.54         4.6k       886.0k         0.0k      70.6M      13.4G       0.0k sda4


      tps    MB_read/s    MB_wrtn/s    MB_dscd/s    MB_read    MB_wrtn    MB_dscd Device
     0.83         0.0k       127.1k         0.0k       0.0k       7.4M       0.0k sda4

[milsav92]

Win 10

• SMART before defrag

241 Lifetime_Writes_GiB     0x0032   000   000   000    Old_age   Always       -       7813
242 Lifetime_Reads_GiB      0x0032   000   000   000    Old_age   Always       -       11058

• Defrag
  Pay attention to the Retrim: block

PS C:\Windows\system32> defrag e: /u /v /h /o

Invoking slab consolidation on SCSI (E:)...

        Slab Analysis:  100% complete.

Performing pass 1:
        Retrim:  0% complete...
        Slab consolidation was skipped because there were few evictable slabs.

        Retrim:  100% complete.

The operation completed successfully.

Post Defragmentation Report:

        Volume Information:
                Volume size                 = 19.99 GB
                Cluster size                = 4 KB
                Used space                  = 5.14 GB
                Free space                  = 14.85 GB

        Allocation Units:
                Slab count                  = 5242111
                Slab size                   = 4 KB
                Slab alignment              = 0 bytes
                In-use slabs                = 1347760

        Slab Consolidation:
                Space efficiency            = 100%
                Potential purgable slabs    = 0
                Slabs pinned unmovable      = 0
                Successfully purged slabs   = 0
                Recovered space             = 0 bytes

        Retrim:
                Backed allocations          = 5242111
                Allocations trimmed         = 3894341
                Total space trimmed         = 14.85 GB

• SMART after defrag

241 Lifetime_Writes_GiB     0x0032   000   000   000    Old_age   Always       -       7815
242 Lifetime_Reads_GiB      0x0032   000   000   000    Old_age   Always       -       11058

• Defrag runtime

PS C:\Windows\system32> Measure-Command { defrag e: /h /o }


Days              : 0
Hours             : 0
Minutes           : 0
Seconds           : 48
Milliseconds      : 748
Ticks             : 487484326
TotalDays         : 0.000564217969907407
TotalHours        : 0.0135412312777778
TotalMinutes      : 0.812473876666667
TotalSeconds      : 48.7484326
TotalMilliseconds : 48748.4326

• iostat

root@PC:~> sudo iostat -mh -d 60 sda4
Linux 5.14.11-2-default (PC)       10/25/2021      _x86_64_        (32 CPU)

      tps    MB_read/s    MB_wrtn/s    MB_dscd/s    MB_read    MB_wrtn    MB_dscd Device
     1.48         4.4k       849.7k         0.0k      70.7M      13.4G       0.0k sda4


      tps    MB_read/s    MB_wrtn/s    MB_dscd/s    MB_read    MB_wrtn    MB_dscd Device
    41.97         0.0k        24.4M         0.0k       0.0k       1.4G       0.0k sda4

[milsav92]

Win 11 and Windows Server 2022 display the same symptoms as Win 10 so it seem that somewhere in the transition from W8.1 to W10 Microsoft changed something in defrag.exe.

If it's a defrag.ex regression do you have an idea how to report the problem to Microsoft?

[vrozenfe]

@milsav92
Thaks a lot for your update.
Our QE should be testing exactly the same platforms - Win10 21H1/Win11 and WS2022 right now.
Honestly, I don't think that this is the MS problem. I rather think that our drivers are missing some
bits required by recent Windows versions.

We will try to investigate the problem, but it might take us some time.

Best,
Vadim.

[peixiu]

Hi @vrozenfe @milsav92,

We tried some tests for this issue, We can reproduce this issue, but it seems the defrag version also will impact the trim result, details as follows:

Tested with 3 different type data disk(blk, scsi, ide):
Commands with blk data disk:
-blockdev node-name=file_stg1,driver=file,cache.direct=on,cache.no-flush=off,filename=/home/stgtest.qcow2,aio=threads,discard=unmap
-blockdev node-name=drive_stg1,driver=qcow2,cache.direct=on,cache.no-flush=off,file=file_stg1,discard=unmap
-device virtio-blk-pci,id=stg1,drive=drive_stg1,bus=pci.2
-device virtio-net-pci,mac=9a:36:83:b6:3d:05,id=idJVpmsF,netdev=id23ZUK6,bus=pci.3 \

Commands with scsi data disk:
-device virtio-scsi-pci,id=scsi1,bus=pci.4,addr=0x0
-blockdev driver=file,filename=/home/stgtest.qcow2,node-name=libvirt-1-storage,cache.direct=on,cache.no-flush=off,auto-read-only=on,discard=unmap
-blockdev node-name=libvirt-1-format,read-only=off,discard=unmap,detect-zeroes=unmap,cache.direct=on,cache.no-flush=off,driver=qcow2,file=libvirt-1-storage
-device scsi-hd,bus=scsi1.0,channel=0,scsi-id=0,lun=0,device_id=drive-scsi0-0-0-1,drive=libvirt-1-format,id=scsi0-0-0-1,write-cache=on \

Commands with ide data disk:
-blockdev driver=file,cache.direct=on,cache.no-flush=off,filename=/home/stgtest.qcow2,node-name=my_file1,aio=threads,discard=unmap
-blockdev driver=qcow2,node-name=my1,file=my_file1,cache.direct=on,cache.no-flush=off,discard=unmap
-device ide-hd,drive=my1,id=ide0-0-1,bus=ide.1,unit=0 \

Test results:

1. ide/blk system disk + blk data disk + defrag d: /u /v /h /o, we can reproduce this issue, cpu usage will up to 60%, and Retrim complete need 10-15mins.

2. ide system disk + scsi data disk + defrag d: /u /v /h /o, we can reproduce this issue, cpu usage will up to 60%, and Retrim complete need 10-15 mins.

3. ide system disk + ide data disk + defrag d: /u /v /h /o, we cannot reproduce this issue, Retrim complete fast, about a few seconds.

Change another win10 image, when tab defrag command in cmd, will auto call Defrag.exe program, so tried test with Defrag.exe, the result has some changes, as follows:
4) ide system disk + blk data disk + Defrag.exe d: /u /v /h /o, cpu usage will up to 60%, but Retrim completed in 2 mins.

5. ide system disk + scsi data disk + Defrag.exe d: /u /v /h /o, cpu usage will up to 60%, but Retrim completed in 2 mins.

6. ide system disk + ide data disk + Defrag.exe d: /u /v /h /o, Retrim complete fast, about a few seconds as well.

We downloaded the smartmontools-7.2, but hit some problems when installing it in windows, so we has not smartctl check, just record the Retrim completed time.

Used versions:
kernel-5.14.0-7.el9.x86_64
qemu-kvm-6.1.0-5.el9.x86_64
seabios-bin-1.14.0-6.el9.noarch
virtio-win-prewhql-208/214

Qemu command lines(just paste one configure):
/usr/libexec/qemu-kvm
-name 'avocado-vt-vm3'
-machine q35
-nodefaults
-vga std
-device pcie-root-port,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x3
-device pcie-root-port,port=0x11,chassis=2,id=pci.2,bus=pcie.0,addr=0x3.0x1
-device pcie-root-port,port=0x12,chassis=3,id=pci.3,bus=pcie.0,addr=0x3.0x2
-device pcie-root-port,port=0x13,chassis=4,id=pci.4,bus=pcie.0,addr=0x3.0x3
-device pcie-root-port,port=0x14,chassis=5,id=pci.5,bus=pcie.0,addr=0x3.0x4
-device pcie-root-port,port=0x15,chassis=6,id=pci.6,bus=pcie.0,addr=0x3.0x5
-device pcie-root-port,port=0x16,chassis=7,id=pci.7,bus=pcie.0,addr=0x3.0x6
-device pcie-root-port,port=0x17,chassis=8,id=pci.8,bus=pcie.0,addr=0x3.0x7
-blockdev driver=file,cache.direct=on,cache.no-flush=off,filename=/home/kvm_autotest_root/images/win10-64-virtio-scsi.qcow2,node-name=my_file,aio=threads,discard=unmap
-blockdev driver=qcow2,node-name=my,file=my_file,cache.direct=on,cache.no-flush=off,discard=unmap
-device ide-hd,drive=my,id=ide0-0-0,bus=ide.0,unit=0,bootindex=0
-device virtio-scsi-pci,id=scsi1,bus=pci.4,addr=0x0
-blockdev driver=file,filename=/home/stgtest.qcow2,node-name=libvirt-1-storage,cache.direct=on,cache.no-flush=off,auto-read-only=on,discard=unmap
-blockdev node-name=libvirt-1-format,read-only=off,discard=unmap,detect-zeroes=unmap,cache.direct=on,cache.no-flush=off,driver=qcow2,file=libvirt-1-storage
-device scsi-hd,bus=scsi1.0,channel=0,scsi-id=0,lun=0,device_id=drive-scsi0-0-0-1,drive=libvirt-1-format,id=scsi0-0-0-1,write-cache=on
-device virtio-net-pci,mac=9a:36:83:b6:3d:05,id=idJVpmsF,netdev=id23ZUK6,bus=pci.3
-netdev tap,id=id23ZUK6,vhost=on
-m 8192
-smp 2,maxcpus=4
-cpu 'Skylake-Server',hv_stimer,hv_synic,hv_vpindex,hv_reset,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time,hv-tlbflush,+kvm_pv_unhalt
-device piix3-usb-uhci,id=usb -device usb-tablet,id=input0
-vnc :10
-rtc base=localtime,clock=host,driftfix=slew
-boot order=cdn,once=c,menu=off,strict=off
-enable-kvm
-qmp tcp:0:1231,server,nowait
-monitor stdio \

Thanks~
Peixiu

[peixiu]

Tried more tests for this case, the results as follows:

We can reproduce this issue with both viostor and vioscsi, tested with virtio-win-prewhql-208 build, the high cpu usage and trim completed need 10-15 mins situations.
Tried update driver version to virtio-win-prewhql-214, also reproduce this situation both with viostor and vioscsi.

Check the used win10 image version is Edition: Windows 10 Enterprise.
Tried to re-install a new win10 image with Edition: Windows 10 Enterprise N, and create a new data image, test again, the issue cannot be reproduced, the trim completed in 2 mins, both for viostor and vioscsi.

And we also tried test on win8.1-64, the trim completed so fast, just a few seconds.
And tried with a previous Windows releases win10-1909, but installed with Windows 10 Enterprise N, also cannot reproduced this issue, the trim completed in a few seconds.

Used versions:
kernel-5.14.0-9.el9.x86_64
qemu-kvm-6.1.0-5.el9.x86_64
seabios-bin-1.14.0-7.el9.noarch
virtio-win-prewhql-208/214

Thanks~
Peixiu