On Sun, Aug 09, 2009 at 06:01:15PM +0300, Avi Kivity wrote: > On 08/09/2009 05:52 PM, Gleb Natapov wrote: >> On Sun, Aug 09, 2009 at 05:56:30PM +0300, Avi Kivity wrote: >> >>> On 08/09/2009 03:41 PM, Gleb Natapov wrote: >>> >>>> Sending of MSI using IRQ routing is an artificial concept and potentially >>>> big number of MSIs (2048 per device) make it also inefficient. This >>>> patch adds an interface to inject MSI messages from userspace to lapic >>>> logic directly. The patch also reduces the maximum number of IRQ routing >>>> entries to 128 since MSIs will no longer go there and 128 entries cover >>>> 5 ioapics and this ought to be enough for anybody. >>>> >>> In the future many MSIs will be triggered via irqfds, and those >>> require irq routing. >>> >>> >> Why? My plan is to change irqfd to use the MSI functions. >> >> > > It's still an "install handle, call handle" interface. Maybe it would > have been better to start off with your new interface, but having both > is too much for too little gain. > Is it not too late to change interface? There was no released kernel with irqfd yet. And this just adds another level of indirection and one more point of false cache sharing. -- 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