Windows 10 + WSL2 not booting under Proxmox VE 7.3


New Member
Feb 7, 2023
I am trying to migrate my VMs from libvirt to proxmox, and ran into this issue.
  1. Set cpu type to host
  2. Add `-hypervisor` cpu flag by using custom cpu type
  3. Install fresh win10
  4. Confirm windows task manager shows host CPU
  5. VM is working fine
  6. Install WSL2
  7. VM no longer boots - hangs on windows splash screen
  8. Change cpu type to kvm
  9. VM boots again, but without nested virtualization support, so WSL2 does not work
  10. :mad:
The same VM image works fine on a similar host using libvirt. The only apparent difference is QEMU version (7.1 in proxmox vs 7.2 on the libvirt host).

Any ideas?

References / things already tried:
The usual system config outputs:
  • qm config
agent: 1
boot: order=sata0
cores: 20
cpu: custom-nvmtest,flags=+pdpe1gb;+hv-tlbflush;+hv-evmcs;+aes
ide2: local:iso/Win10_22H2_English_x64.iso,media=cdrom,size=5971862K
machine: pc-q35-7.1
memory: 16348
meta: creation-qemu=7.1.0,ctime=1675662131
name: win10-fresh-tmp
net0: e1000=8A:45:1E:DA:10:19,bridge=vmbr0,firewall=1
numa: 0
ostype: win10
sata0: local-lvm:vm-103-disk-0,cache=writeback,discard=on,size=100G,ssd=1
scsihw: virtio-scsi-single
smbios1: uuid=93521e68-6ee0-40cb-a93f-919d45122bd8
sockets: 1
vmgenid: 9c38ffeb-a53d-4e47-837d-c50826b8df9a
  • qm showcmd
/usr/bin/kvm -id 103 -name 'win10-fresh-tmp,debug-threads=on' -no-shutdown -chardev 'socket,id=qmp,path=/var/run/qemu-server/103.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/ -daemonize -smbios 'type=1,uuid=93521e68-6ee0-40cb-a93f-919d45122bd8' -smp '20,sockets=1,cores=20,maxcpus=20' -nodefaults -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' -vnc 'unix:/var/run/qemu-server/103.vnc,password=on' -no-hpet -cpu 'host,+aes,+hv-evmcs,+hv-tlbflush,hv_ipi,hv_relaxed,hv_reset,hv_runtime,hv_spinlocks=0x1fff,hv_stimer,hv_synic,hv_time,hv_vapic,hv_vendor_id=GenuineIntel,hv_vpindex,-hypervisor,kvm=off,+kvm_pv_eoi,+kvm_pv_unhalt,+pdpe1gb,host-phys-bits=true' -m 16348 -readconfig /usr/share/qemu-server/pve-q35-4.0.cfg -device 'vmgenid,guid=9c38ffeb-a53d-4e47-837d-c50826b8df9a' -device 'usb-tablet,id=tablet,bus=ehci.0,port=1' -device 'VGA,id=vga,bus=pcie.0,addr=0x1,edid=off' -chardev 'socket,path=/var/run/qemu-server/103.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' -device 'virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3,free-page-reporting=on' -iscsi '' -drive 'file=/var/lib/vz/template/iso/Win10_22H2_English_x64.iso,if=none,id=drive-ide2,media=cdrom,aio=io_uring' -device 'ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2' -device 'ahci,id=ahci0,multifunction=on,bus=pci.0,addr=0x7' -drive 'file=/dev/pve/vm-103-disk-0,if=none,id=drive-sata0,cache=writeback,discard=on,format=raw,aio=io_uring,detect-zeroes=unmap' -device 'ide-hd,bus=ahci0.0,drive=drive-sata0,id=sata0,rotation_rate=1,bootindex=100' -netdev 'type=tap,id=net0,ifname=tap103i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown' -device 'e1000,mac=8A:45:1E:DA:10:19,netdev=net0,bus=pci.0,addr=0x12,id=net0' -rtc 'driftfix=slew,base=localtime' -machine 'type=pc-q35-7.1+pve0' -global 'kvm-pit.lost_tick_policy=discard'
  • pveversion -v
proxmox-ve: 7.3-1 (running kernel: 5.15.83-1-pve)
pve-manager: 7.3-4 (running version: 7.3-4/d69b70d4)
pve-kernel-helper: 7.3-3
pve-kernel-5.15: 7.3-1
pve-kernel-5.15.83-1-pve: 5.15.83-1
pve-kernel-5.15.74-1-pve: 5.15.74-1
ceph-fuse: 15.2.17-pve1
corosync: 3.1.7-pve1
criu: 3.15-1+pve-1
glusterfs-client: 9.2-1
ifupdown2: 3.1.0-1+pmx3
ksm-control-daemon: 1.4-1
libjs-extjs: 7.0.0-1
libknet1: 1.24-pve2
libproxmox-acme-perl: 1.4.3
libproxmox-backup-qemu0: 1.3.1-1
libpve-access-control: 7.3-1
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.3-2
libpve-guest-common-perl: 4.2-3
libpve-http-server-perl: 4.1-5
libpve-storage-perl: 7.3-2
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 5.0.2-1
lxcfs: 5.0.3-pve1
novnc-pve: 1.3.0-3
proxmox-backup-client: 2.3.2-1
proxmox-backup-file-restore: 2.3.2-1
proxmox-mini-journalreader: 1.3-1
proxmox-widget-toolkit: 3.5.3
pve-cluster: 7.3-2
pve-container: 4.4-2
pve-docs: 7.3-1
pve-edk2-firmware: 3.20220526-1
pve-firewall: 4.2-7
pve-firmware: 3.6-3
pve-ha-manager: 3.5.1
pve-i18n: 2.8-2
pve-qemu-kvm: 7.1.0-4
pve-xtermjs: 4.16.0-1
qemu-server: 7.3-3
smartmontools: 7.2-pve3
spiceterm: 3.2-2
swtpm: 0.8.0~bpo11+2
vncterm: 1.7-1
zfsutils-linux: 2.1.9-pve1
  • host cpuinfo
processor : 19
vendor_id : GenuineIntel
cpu family : 6
model : 151
model name : 12th Gen Intel(R) Core(TM) i7-12700K
stepping : 2
microcode : 0xd
cpu MHz : 3600.000
cache size : 25600 KB
physical id : 0
siblings : 20
core id : 39
cpu cores : 12
apicid : 78
initial apicid : 78
fpu : yes
fpu_exception : yes
cpuid level : 32
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb cat_l2 invpcid_single cdp_l2 ssbd ibrs ibpb stibp ibrs_enhanced tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid rdt_a rdseed adx smap clflushopt clwb intel_pt sha_ni xsaveopt xsavec xgetbv1 xsaves split_lock_detect avx_vnni dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp hwp_pkg_req umip pku ospke waitpkg gfni vaes vpclmulqdq tme rdpid movdiri movdir64b fsrm md_clear serialize pconfig arch_lbr flush_l1d arch_capabilities
vmx flags : vnmi preemption_timer posted_intr invvpid ept_x_only ept_ad ept_1gb flexpriority apicv tsc_offset vtpr mtf vapic ept vpid unrestricted_guest vapic_reg vid ple shadow_vmcs ept_mode_based_exec tsc_scaling usr_wait_pause
bugs : spectre_v1 spectre_v2 spec_store_bypass swapgs eibrs_pbrsb
bogomips : 7219.20
clflush size : 64
cache_alignment : 64
address sizes : 46 bits physical, 48 bits virtual
power management:
Did you ever figure this out?

The only solution I had while using cpu type host was to boot in safe mode and uninstall the hypervisor feature (which obviously means WSL isn't working).
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