qemu-kvm crashes early during boot on Intel Merom CPU

[Marc D.]

Package: seabios
Version: 1.13.0-1

In a freshly installed (approx. 7 days ago), fully updated focal system on x86_64, I tried to run a simple KVM VM with qemu-kvm, seabios and configured by libvirt. It contained an approx. 7 days old ubuntu-server install ISO for Ubuntu focal and a LV.

When starting the VM, it immediately goes into paused state. The log reveals that it has crashed:

KVM internal error. Suberror: 1
emulation failure

The host contains an Intel Merom CPU (mobile successor of Intel Conroe). Libvirt's attempt at guest CPU configuration resulted in:

-cpu Conroe,vme=on,vmx=on,cx16=on,x2apic=on,tsc-deadline=on,hypervisor=on,arat=on,tsc-adjust=on,arch-capabilities=on,skip-l1dfl-vmentry=on

No attempt at reconfiguring the guest CPU was successful.

I noticed, however, that the same software could boot the VM on a different Computer with a Sandy Bridge CPU, that was modeled by libvirt as:

-cpu SandyBridge-IBRS,vme=on,vmx=on,pcid=on,hypervisor=on,arat=on,tsc-adjust=on,umip=on,md-clear=on,stibp=on,arch-capabilities=on,ssbd=on,xsaveopt=on,ibpb=on,amd-ssbd=on,skip-l1dfl-vmentry=on

Also, with version 1.12.0-1 of seabios from Ubuntu eoan, the VM boots fine on the Merom CPU.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: seabios 1.13.0-1
ProcVersionSignature: Ubuntu 5.4.0-18.22-lowlatency 5.4.24
Uname: Linux 5.4.0-18-lowlatency x86_64
ApportVersion: 2.20.11-0ubuntu20
Architecture: amd64
CurrentDesktop: LXQt
Date: Sat Mar 14 13:50:59 2020
Dependencies:

InstallationDate: Installed on 2020-03-07 (7 days ago)
InstallationMedia: Lubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
PackageArchitecture: all
SourcePackage: seabios
UpgradeStatus: No upgrade log present (probably fresh install)