Re: [PATCH v3 3/6] vbus: add a "vbus-proxy" bus model for vbus_driverobjects

From: Avi Kivity
Date: Tue Aug 18 2009 - 15:08:25 EST


On 08/18/2009 09:20 PM, Arnd Bergmann wrote:
Well, the interrupt model to name one.
The performance aspects of your interrupt model are independent
of the vbus proxy, or at least they should be. Let's assume for
now that your event notification mechanism gives significant
performance improvements (which we can't measure independently
right now). I don't see a reason why we could not get the
same performance out of a paravirtual interrupt controller
that uses the same method, and it would be straightforward
to implement one and use that together with all the existing
emulated PCI devices and virtio devices including vhost_net.

Interesting. You could even configure those vectors using the standard MSI configuration mechanism; simply replace the address/data pair with something meaningful to the paravirt interrupt controller.

I'd have to see really hard numbers to be tempted to merge something like this though. We've merged paravirt mmu, for example, and now it underperforms both hardware two-level paging and software shadow paging.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

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