I have realized that if I set the CPU to coreDuo in QEMU rather than core2Duo, my run/bomb program would not give any output at all.
My real CPU is a dual core. But the BIOS does not enable virtualization per default. I believe I have a CPU with vmx flag, that does not have IOMMU (dmidecode does not show a DMAR (DMA relocalistion) table).
Here is my /proc/cpuinfo: processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz stepping : 6 microcode : 0xd0 cpu MHz : 1821.338 cache size : 2048 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 10 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 lm constant_tsc arch_perfmon pebs bts nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm pti tpr_shadow dtherm bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass bogomips : 3721.03 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management:
I had the idea to test run/bomb in QEMU with my host CPU, but after installing a KVM linux kernel, it was not booting (if BIOS have virtualization enabled, would hang on loading boot image kind of message).
I do remember that a few years ago, the author of Nova, had it modified so that it booted on my Pentium 4. But I guess something went wrong with the years. He sure did not really happy back then to know that people where still using CPU that does not support IOMMU.
I tried with Pentium3 emulation and QEMU after 3 to 5 mins, said that the program had try to write outside memory, and that it probably means I was running an image not compatible with my machine.
Now, I suppose that the fact QEMU cannot handle some older CPUs on Nova well... that there is some way to debug it in an easier way than on real hardware? I am still trying to figure how ... however.