On 24.11.2009, at 20:25, Anthony Liguori wrote: > Alexander Graf wrote: >> On 24.11.2009, at 19:55, Anthony Liguori wrote: >> >> >>> Alexander Graf wrote: >>> >>>> On our S390x Virtio machine we don't have anywhere to display early printks >>>> on, because we don't know about VGA or serial ports. >>>> >>>> So instead we just forward everything to the virtio console that we created >>>> anyways. >>>> >>> What is this used for? >>> >> >> This is used for console output before virtio is initialized. I didn't >> invent it - that's the way it's implemented in the s390 kernels today. >> > > I don't see any code that calls this function. Am I missing something > obvious?
It gets called from target-s390x/kvm.c using a special hypercall instruction. Alex
