Prior to the fix starting a host-model guest on GCE:

ubuntu@nested-vm:~$ virsh start focal
error: Failed to start domain focal
error: internal error: process exited while connecting to monitor: 2020-06-23T09:54:47.062832Z qemu-system-x86_64: warning: host doesn't support requested feature: MSR(48FH).vmx-exit-load-perf-global-ctrl [bit 12]
2020-06-23T09:54:47.062847Z qemu-system-x86_64: warning: host doesn't support requested feature: MSR(490H).vmx-entry-load-perf-global-ctrl [bit 13]
2020-06-23T09:54:47.062862Z qemu-system-x86_64: warning: host doesn't support requested feature: MSR(48CH).vmx-ept-execonly [bit 0]
2020-06-23T09:54:47.062875Z qemu-system-x86_64: warning: host doesn't support requested feature: MSR(48CH).vmx-eptad [bit 21]
2020-06-23T09:54:47.062891Z qemu-system-x86_64: warning: host doesn't support requested feature: MSR(491H).vmx-eptp-switching [bit 0]
2020-06-23T09:54:47.063762Z qemu-system-x86_64: error: failed to set MSR 0x48b to 0x159ff00000000
qemu-system-x86_64: /build/qemu-FC5BvZ/qemu-4.2/target/i386/kvm.c:2680: kvm_buf_set_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.


Updating to focal-proposed worked nicely, retesting the case ...


ubuntu@nested-vm:~$ virsh start focal
Domain focal started

The guest is up and running

ubuntu@nested-vm:~$ virsh list
 Id   Name    State
-----------------------
 3    focal   running

The guest log is now without errors:
2020-06-23 09:57:29.845+0000: starting up libvirt version: 6.0.0, package: 0ubuntu8.1 (Christian Ehrhardt <email address hidden> Wed, 20 May 2020 06:59:57 +0200), qemu version: 4.2.0Debian 1:4.2-3ubuntu6.3, kernel: 5.4.0-1015-gcp, hostname: nested-vm.c.prjparide.internal
LC_ALL=C \
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin \
HOME=/var/lib/libvirt/qemu/domain-3-focal \
XDG_DATA_HOME=/var/lib/libvirt/qemu/domain-3-focal/.local/share \
XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain-3-focal/.cache \
XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain-3-focal/.config \
QEMU_AUDIO_DRV=spice \
/usr/bin/qemu-system-x86_64 \
-name guest=focal,debug-threads=on \
-S \
-object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-3-focal/master-key.aes \
-machine pc-q35-focal,accel=kvm,usb=off,dump-guest-core=off \
-cpu Broadwell-IBRS,vme=on,ss=on,vmx=on,f16c=on,rdrand=on,hypervisor=on,arat=on,tsc-adjust=on,umip=on,md-clear=on,stibp=on,arch-capabilities=on,ssbd=on,xsaveopt=on,abm=on,ibpb=on,amd-ssbd=on,rsba=on,skip-l1dfl-vmentry=on \
-m 512 \
-overcommit mem-lock=off \
-smp 1,sockets=1,cores=1,threads=1 \
-uuid 2e2a0717-613b-4f9c-91eb-59f93f5ecddb \
-no-user-config \
-nodefaults \
-chardev socket,id=charmonitor,fd=30,server,nowait \
-mon chardev=charmonitor,id=monitor,mode=control \
-rtc base=utc \
-no-shutdown \
-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 pcie-root-port,port=0x16,chassis=7,id=pci.7,bus=pcie.0,addr=0x2.0x6 \
-device qemu-xhci,id=usb,bus=pci.2,addr=0x0 \
-device virtio-serial-pci,id=virtio-serial0,bus=pci.3,addr=0x0 \
-blockdev '{"driver":"file","filename":"/var/lib/uvtool/libvirt/images/x-uvt-b64-Y29tLnVidW50dS5jbG91ZC5kYWlseTpzZXJ2ZXI6MjAuMDQ6YW1kNjQgMjAyMDA2MjI=","node-name":"libvirt-3-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-3-format","read-only":true,"driver":"qcow2","file":"libvirt-3-storage","backing":null}' \
-blockdev '{"driver":"file","filename":"/var/lib/uvtool/libvirt/images/focal.qcow","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-2-format","read-only":false,"driver":"qcow2","file":"libvirt-2-storage","backing":"libvirt-3-format"}' \
-device virtio-blk-pci,scsi=off,bus=pci.4,addr=0x0,drive=libvirt-2-format,id=virtio-disk0,bootindex=1 \
-blockdev '{"driver":"file","filename":"/var/lib/uvtool/libvirt/images/focal-ds.qcow","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"qcow2","file":"libvirt-1-storage","backing":null}' \
-device virtio-blk-pci,scsi=off,bus=pci.5,addr=0x0,drive=libvirt-1-format,id=virtio-disk1 \
-netdev tap,fd=32,id=hostnet0,vhost=on,vhostfd=33 \
-device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:d5:43:8f,bus=pci.1,addr=0x0 \
-chardev pty,id=charserial0 \
-device isa-serial,chardev=charserial0,id=serial0 \
-chardev socket,id=charchannel0,fd=34,server,nowait \
-device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0 \
-vnc 127.0.0.1:0 \
-spice port=5901,addr=127.0.0.1,disable-ticketing,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 virtio-balloon-pci,id=balloon0,bus=pci.6,addr=0x0 \
-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
-msg timestamp=on
char device redirected to /dev/pts/3 (label charserial0)


Marking as verified