On Mon, May 25, 2009 at 02:08:26PM +0800, Sheng Yang wrote: > On Friday 22 May 2009 01:37:53 Gleb Natapov wrote: > > This is implementation of x2apic for KVM that I wrote a while ago. > > Unfortunately there is no guest that can take advantage of it since > > Linux doesn't (yet?) use x2apic if interrupt remapping is not enabled > > and I don't feel like implement interrupt remapping device :) > > > > Re-based to latest kvm tree for your viewing pleasure and feedback. > > Yeah... x2apic is for interrupt remapping, and interrupt remapping is for VT-d > engine. So if we don't want to virtualize VT-d engine and interrupt remapping, > x2apic is useless for the guest... And VT-d engine(and related things) > virtualization is far from our scope now... > Can you explain why "x2apic is for interrupt remapping"? I can understand why interrupt remapping is needed to use x2apic in certain circumstances (apic ids > 256). x2apic has better virtualizable interface and that is why we want to emulate it. Can you name one technical reason why it can't be done in a context of KVM? -- Gleb. -- 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
