Am 18.04.2013 um 10:30 schrieb Peter Maydell <peter.maydell@xxxxxxxxxx>: > On 18 April 2013 07:49, Marc Zyngier <maz@xxxxxxxxxxxxxxx> wrote: >> If you need an early console, why not simply wire the 8250 emulation in >> kvmtool to be useable from the MMIO bus? I reckon this would solve your >> problem in a more elegant way... > > The other approach I thought of would be something involving > defining a hypercall interface for console I/O, in the same > way that we have hypercalls for "start cpu"/"stop cpu"/etc. > Is there any mileage in considering that approach, or is it > a non-starter? It's exactly what we had for the s390-virtio machine. Virtio-console as console device plus a hypercall for early printk. It was a mess. Trying to inject character output that lands in machine context, where hypercalls get handled, inside of a specific virtio-console device, which owns the char output, is hard. We haven't found any good solution in qemu to layer this properly. The closest approach to something workable was to create 2 char outputs and mux them together, like you usually would mus monitor and serial. Good luck muxing that one again with the monitor :). I'd rather spare you guys from going through the same pain. Alex _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
