On 2012-10-25 18:14, Paolo Bonzini wrote: > Il 24/10/2012 02:50, Paul Mackerras ha scritto: >> So we could indeed use the existing KVM_CREATE_IRQCHIP to tell KVM to >> create a presentation controller per vcpu. But then how do we tell >> KVM how many source controllers we want and how many interrupts each >> source controller should handle? The source controllers are not tied >> to any particular vcpu, and a source controller could potentially have >> 100s of interrupts or more (particularly with MSIs). Configuration of >> each source fits into 64 bits, so if we tried to use KVM_SET_IRQCHIP >> for configuring a source controller we'd be limited to 64 interrupts >> per source controller. > > As Jan said, there's more than a few similarities between the x86 and > PPC model. > > Taking inspiration from the x86 API, configuring the source controller > seems to be more of a task for KVM_SET_GSI_ROUTING (a very x86-centric > name, I must admit). For wiring things together, I agree. But the IOAPIC has a fixed number of input lines per chip, Power needs to configure them. I don't think deriving this from addressed lines is the best solution. Some lines may be configured (too) late, when the chip should have defined its configuration already. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE 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
