Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [RFC PATCH v2 00/19] virtual-bus | Date | Sat, 6 Jun 2009 00:05:46 +0930 |
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On Fri, 5 Jun 2009 09:26:48 pm Gregory Haskins wrote: > Hi Rusty, > > Rusty Russell wrote: > > On Fri, 5 Jun 2009 04:19:17 am Gregory Haskins wrote: > >> Avi Kivity wrote: > >>> Gregory Haskins wrote: > >>> One idea is similar to signalfd() or eventfd() > >> > >> And thus the "kvm-eventfd" (irqfd/iosignalfd) interface project was > >> born. ;) > > > > The lguest patch queue already has such an interface :) > > Cool! Ultimately I think it will be easier if both lguest+kvm support > the same eventfd notion so this is good you are already moving in the > same direction.
Not really; lguest doesn't do PCI.
> > And I have a partially complete in-kernel virtio_pci patch with the same > > trick. > > I thought lguest didn't use pci? Or do you just mean that you have an > in-kernel virtio-net for lguest?
No, this was for kvm. Sorry for the confusion.
> Other than the potential rcu issues that Paul already addressed, looks > good. FWIW: this looks like what we are calling "iosignalfd" on the kvm > land (unless I am misunderstanding). Do you have the equivalent of > "irqfd" going the other way?
Yes; lguest uses write() (offset indicates cpu #) rather than ioctls, but anyone can do the LHREQ_IRQ write to queue an interrupt for delivery.
So the threads just get the same /dev/lguest fd and it's simple.
Thanks! Rusty.
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