Thanks Masato, since thta sounds more like an issue in the kernel you refer to I have added a bug task for `linux-oem-5.13` to be triaged from the kernel POV as well.
** Also affects: linux-oem-5.13 (Ubuntu) Importance: Undecided Status: New ** Changed in: qemu (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-oem-5.13 in Ubuntu. https://bugs.launchpad.net/bugs/1944104 Title: nested vm on vm not running Status in linux-oem-5.13 package in Ubuntu: New Status in qemu package in Ubuntu: Incomplete Bug description: The host machine ubuntu 20.04 kernel is 5.13.0-1012-oem, When the kernel of the guest machine is ubuntu 20.04 kernel 5.4.0-84-generic, vm cannot be started on the guest machine. ------------------------------------- KVM: entry failed, hardware error 0x7 EAX=00000000 EBX=00000000 ECX=00000000 EDX=000a0671 ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000 EIP=0000fff0 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300 CS =f000 ffff0000 0000ffff 00009b00 SS =0000 00000000 0000ffff 00009300 DS =0000 00000000 0000ffff 00009300 FS =0000 00000000 0000ffff 00009300 GS =0000 00000000 0000ffff 00009300 LDT=0000 00000000 0000ffff 00008200 TR =0000 00000000 0000ffff 00008b00 GDT= 00000000 0000ffff IDT= 00000000 0000ffff CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000 Code=90 90 90 90 eb c3 90 90 90 90 90 90 00 00 00 00 56 54 46 00 <90> 90 eb ac 90 90 90 90 90 90 90 90 90 90 90 90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ------------------------------------- host kernel 5.4.0-84-generic gust kernel 5.4.0-84-generic: OK gust kernel 5.13.0-1012-oem : OK host kernel 5.13.0-1012-oem gust kernel 5.4.0-84-generic: NG gust kernel 5.13.0-1012-oem : OK ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: qemu-system-x86 1:4.2-3ubuntu6.17 ProcVersionSignature: Ubuntu 5.4.0-84.94-generic 5.4.133 Uname: Linux 5.4.0-84-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.20 Architecture: amd64 CasperMD5CheckResult: pass Date: Mon Sep 20 14:05:09 2021 ExecutablePath: /usr/bin/qemu-system-x86_64 InstallationDate: Installed on 2021-09-20 (0 days ago) InstallationMedia: Ubuntu-Server 20.04.2 LTS "Focal Fossa" - Release amd64 (20210201.2) Lsusb: Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd QEMU USB Tablet Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Lsusb-t: /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/6p, 480M |__ Port 1: Dev 2, If 0, Class=Human Interface Device, Driver=usbhid, 480M MachineType: QEMU Standard PC (Q35 + ICH9, 2009) ProcEnviron: PATH=(custom, no user) ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-84-generic root=/dev/mapper/vg-lv_root ro intel_iommu=on amd_iommu=on SourcePackage: qemu UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 02/06/2015 dmi.bios.vendor: EFI Development Kit II / OVMF dmi.bios.version: 0.0.0 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-q35-4.2 dmi.modalias: dmi:bvnEFIDevelopmentKitII/OVMF:bvr0.0.0:bd02/06/2015:svnQEMU:pnStandardPC(Q35+ICH9,2009):pvrpc-q35-4.2:cvnQEMU:ct1:cvrpc-q35-4.2: dmi.product.name: Standard PC (Q35 + ICH9, 2009) dmi.product.version: pc-q35-4.2 dmi.sys.vendor: QEMU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-oem-5.13/+bug/1944104/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp