On Tue, 30 Oct 2012 14:43:10 +0100 Alexander Graf <agraf@xxxxxxx> wrote: > On 10/30/2012 01:59 PM, Cornelia Huck wrote: > > On Mon, 29 Oct 2012 19:14:19 +0100 > > Alexander Graf<agraf@xxxxxxx> wrote: > > > >> On 29.10.2012, at 14:07, Cornelia Huck wrote: > >> > >>> This code is transport agnostic and can be used by both the legacy > >>> virtio code and virtio_ccw. > >> Would it be possible to actually send real virtio or sclp console commands for early printk? That'd make things a lot easier on the user space end. Combining two completely separate character channels (early printk + sclp or early printk + virtio-console) is really tricky. > >> > > This code is only used if we use a virtio console device. The sclp > > code path is completely different. > > Ah, so the sclp early console works differently? sclp consoles are registered via console_initcall(). I'm not aware of 'early' handling there (although I don't really know the code well.) > > > What do you mean with "real virtio console commands"? The message is > > just put on the output queue anyway. > > For virtio-console, yes. For the early printk it is sent to the > hypervisor using a hypercall, not through the virtio queue. So it > arrives at a completely different end point that usually has no > knowledge of the virtio-console output driver. virtio setup is a core_initcall, which is done way later than the console_initcalls (including s390_virtio_console_init). According to the comments, virtio_cons_early_init is there exactly for that reason. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
