On 2011-01-12 11:31, Jan Kiszka wrote: > Am 12.01.2011 11:22, Avi Kivity wrote: >> On 01/11/2011 03:54 PM, Anthony Liguori wrote: >>> >>> Right, we should introduce a KVMBus that KVM devices are created on. >>> The devices can get at KVMState through the BusState. >> >> There is no kvm bus in a PC (I looked). We're bending the device model >> here because a device is implemented in the kernel and not in >> userspace. An implementation detail is magnified beyond all proportions. >> >> An ioapic that is implemented by kvm lives in exactly the same place >> that the qemu ioapic lives in. An assigned pci device lives on the PCI >> bus, not a KVMBus. If we need a pointer to KVMState, then we must find >> it elsewhere, not through creating imaginary buses that don't exist. >> > > Exactly. > > So we can either "infect" the whole device tree with kvm (or maybe a > more generic accelerator structure that also deals with Xen) or we need > to pull the reference inside the device's init function from some global > service (kvm_get_state). Note that this topic is still waiting for good suggestions, specifically from those who believe in kvm_state references :). This is not only blocking kvmstate merge but will affect KVM irqchips as well. It boils down to how we reasonably pass a kvm_state reference from machine init code to a sysbus device. I'm probably biased, but I don't see any way that does not work against the idea of confining access to kvm_state or breaks device instantiation from the command line or a config file. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- 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
