• Sebastian Andrzej Siewior's avatar
    rcutorture: Tweak kvm options · a6fda6da
    Sebastian Andrzej Siewior authored
    In one of my rcutorture tests the TSC clocksource got marked unstable
    due to a large difference in the TSC value. I'm not sure if the guest
    run for a long time with disabled interrupts or if the host was very
    busy and didn't schedule the guest for some time.
    
    I took a look on the qemu/KVM options and decided to update the options:
    
    - Use kvm{32|64} as CPU. We could probably use `host' (like ARM does)
      for maximum available features but since we don't run any userland I'm
      not sure if it makes any difference.
    
    - Drop the "noapic" option. There is no history why the APIC was disabled,
      I see no reason for it.  Once old qemu versions fade away, we can add
      "x2apic=on,tsc-deadline=on,hypervisor=on,tsc_adjust=on".
    
    - Additional config options. It ensures that the kernel knowns that it
      runs as a kvm guest and can use virt devices like the kvm-clock as
      clocksource. The kvm-clock was the main motivation here.
    
    - I didn't add a random HW device. It would make the random device ready
      earlier (not it doesn't complete the initialisation at all) but I
      doubt that there is any need for this.
    Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
    [ paulmck: The world is not quite ready for CONFIG_PARAVIRT_SPINLOCKS=y
      and x2apic, so they are omitted for the time being. ]
    Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
    a6fda6da
functions.sh 6.25 KB