On Friday 01 October 2010 00:44:51 Marcelo Tosatti wrote: > On Tue, Sep 28, 2010 at 05:44:09PM +0800, Sheng Yang wrote: > > Hi Avi & Marcelo > > > > This patchset would add emulation of MSI-X mask bit for assigned devices > > in QEmu. > > > > BTW: We are also purposed an acceleration of MSI-X mask bit for KVM - to > > get it done in kernel. That's because sometime MSI-X mask bit was > > accessed very frequently by guest and emulation in QEmu cost a lot(tens > > to hundreds percent CPU utilization sometime), e.g. guest using Linux > > 2.6.18 or under some heavy workload. The method has been proved > > efficient in Xen, but it would require VMM to handle MSI-X table. Is > > that OK with you? > > It would be good to understand where that cost is, before. Eg. do you > commit kvm irq route frequently when guest unmasks? I don't think it would cause performance issue, but maybe need another bulk of codes in kernel. I would post the in-kernel patch later, which is easier for discuss. :) -- regards Yang, Sheng -- 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
