That is awesome David, qemu64 is like a very low common denominator with only very basic CPU features. While "copy host" means "enable all you can".
We can surely work with that a bit, but until I get access to the same HW I need you to do it. If you run in a console `$virsh domcapabilities` it will spew some XML at you. One of the sections will be for "host-model". In my case that looks like <mode name='host-model' supported='yes'> <model fallback='forbid'>Skylake-Client-IBRS</model> <vendor>Intel</vendor> <feature policy='require' name='ss'/> <feature policy='require' name='vmx'/> <feature policy='require' name='hypervisor'/> ... </mode> That means a names CPU type (the one that is closest to what you have) and some feature additionally enabled/disabled. If you could please post the full output you have, that can be useful. >From there you could go two steps. 1. as you see in my example it will list some cpu features on top of the named type. If you remove them one by one you might be able to identify the single-cpu featute that breaks in your case. 2. The named CPU that you have also has a representation, it can be found in /usr/share/libvirt/cpu_map... That ill list all the CPU features that make up the named type. If #1 wasn't sufficient, you can now add those to your guest definition one by one in disabled state, example <feature policy='disable' name='ss'/> A description of the underlying mechanism is here https://libvirt.org/formatdomain.html#cpu-model-and-topology -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1915063 Title: Windows 10 wil not install using qemu-system-x86_64 Status in QEMU: New Status in qemu package in Ubuntu: Confirmed Bug description: Steps to reproduce install virt-manager and ovmf if nopt already there copy windows and virtio iso files to /var/lib/libvirt/images Use virt-manager from local machine to create your VMs with the disk, CPUs and memory required Select customize configuration then select OVMF(UEFI) instead of seabios set first CDROM to the windows installation iso (enable in boot options) add a second CDROM and load with the virtio iso change spice display to VNC Always get a security error from windows and it fails to launch the installer (works on RHEL and Fedora) I tried updating the qemu version from Focals 4.2 to Groovy 5.0 which was of no help --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu27.14 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME DistributionChannelDescriptor: # This is the distribution channel descriptor for the OEM CDs # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-sutton-focal-amd64-20201030-422+pc-sutton-bachman-focal-amd64+X00 DistroRelease: Ubuntu 20.04 InstallationDate: Installed on 2021-01-20 (19 days ago) InstallationMedia: Ubuntu 20.04 "Focal" - Build amd64 LIVE Binary 20201030-14:39 MachineType: LENOVO 30E102Z NonfreeKernelModules: nvidia_modeset nvidia Package: linux (not installed) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.6.0-1042-oem root=UUID=389cd165-fc52-4814-b837-a1090b9c2387 ro locale=en_US quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 5.6.0-1042.46-oem 5.6.19 RelatedPackageVersions: linux-restricted-modules-5.6.0-1042-oem N/A linux-backports-modules-5.6.0-1042-oem N/A linux-firmware 1.187.8 RfKill: Tags: focal Uname: Linux 5.6.0-1042-oem x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip docker kvm libvirt lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 07/29/2020 dmi.bios.vendor: LENOVO dmi.bios.version: S07KT08A dmi.board.name: 1046 dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.type: 3 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrS07KT08A:bd07/29/2020:svnLENOVO:pn30E102Z:pvrThinkStationP620:rvnLENOVO:rn1046:rvrNotDefined:cvnLENOVO:ct3:cvrNone: dmi.product.family: INVALID dmi.product.name: 30E102Z dmi.product.sku: LENOVO_MT_30E1_BU_Think_FM_ThinkStation P620 dmi.product.version: ThinkStation P620 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1915063/+subscriptions