On 8 July 2013 13:59, Alexander Graf <agraf@xxxxxxx> wrote: > On 08.07.2013, at 14:57, Alexander Graf wrote: >> On 27.06.2013, at 15:04, Peter Maydell wrote: >>> The basic idea is that the board instantiates some transports, >> >> I really dislike that idea. Couldn't you also create a new >> bus for your vexpress platform and add a virtio-mmio-vexpress >> device that automatically allocates an interrupt from the main >> PIC on instantiation? That way you could create transports >> using -device. This doesn't seem to gain anything except that the user has to use -device twice rather than once. >> Combine that with automatic fdt generation and you get fully >> command line scaling device creation. > > Ah, you already have the fdt generation bit. So you're really > only missing the automatic irq allocation to make it actually > user friendly and flexible. It's not clear to me how you can automatically allocate an IRQ: there just aren't that many available, and I'm already a bit nervous about stealing 4, because we might run into issues if newer versions of h/w use those IRQs for something else. One approach would be to have all virtio transports share an IRQ line (the spec currently forbids this; I need to test if it would actually work in practice...) As far as I know there's no way to find out at board construction how many virtio devices you might want. thanks -- PMM _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
