boot hang at "x86: Booting SMP configuration:"

[whentojump]

Workaround

If the host supports KVM

sudo usermod -aG kvm $USER
newgrp kvm

Otherwise

Modify the script:

Change the below from "2" to "1"

linux-mcdc/scripts/q

Line 24 in 4ff8e7b

VM_NUM_CPU=${VM_NUM_CPU:-2}

or change the below from "max" to one of the named CPU models, e.g. "Haswell"

linux-mcdc/scripts/q

Line 127 in 4ff8e7b

cpu="max"

Description

Kernel log before hang

...
[    0.500260] LSM: Security Framework initializing
[    0.504057] SELinux:  Initializing.
[    0.520180] Mount-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
[    0.520772] Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
[    0.697987] smpboot: CPU0: AMD QEMU TCG CPU version 2.5+ (family: 0xf, model: 0x6b, stepping: 0x1)
[    0.720005] Performance Events: PMU not available due to virtualization, using software events only.
[    0.723203] signal: max sigframe size: 3632
[    0.725544] rcu: Hierarchical SRCU implementation.
[    0.741763] smp: Bringing up secondary CPUs ...
[    0.752852] x86: Booting SMP configuration:

On a CloudLab c6420 instance:

• -cpu max -smp 2 hang

  smpboot: CPU0: AMD QEMU TCG CPU version 2.5+ (family: 0xf, model: 0x6b, stepping: 0x1)
  

• -cpu max -smp 1 boot

  smpboot: CPU0: AMD QEMU TCG CPU version 2.5+ (family: 0xf, model: 0x6b, stepping: 0x1)
  

• -cpu Cascadelake-Server -smp 2 boot

  smpboot: CPU0: Intel Xeon Processor (Cascadelake) (family: 0x6, model: 0x55, stepping: 0x6)
  

• -cpu host -smp 2 boot

  smpboot: CPU0: Intel(R) Xeon(R) Gold 6142 CPU @ 2.60GHz (family: 0x6, model: 0x55, stepping: 0x4)
  

On an Intel i9-14900K PC:

• -cpu max -smp 2 hang

  smpboot: CPU0: AMD QEMU TCG CPU version 2.5+ (family: 0xf, model: 0x6b, stepping: 0x1)
  

• -cpu host -smp 2 boot

  smpboot: CPU0: Intel(R) Core(TM) i9-14900K (family: 0x6, model: 0xb7, stepping: 0x1)
  

On an EngIT VM (Intel Xeon Silver 4216 (2) @ 2.095GHz):

• -cpu max -smp 2 boot

  smpboot: CPU0: AMD QEMU TCG CPU version 2.5+ (family: 0xf, model: 0x6b, stepping: 0x1)