Messages in this thread | | | Subject | Re: [PATCH v10 2/2] kvm: Add resampling irqfds for level triggered interrupts | From | Alex Williamson <> | Date | Wed, 19 Sep 2012 07:54:32 -0600 |
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On Wed, 2012-09-19 at 12:10 +0300, Avi Kivity wrote: > On 09/19/2012 12:08 PM, Michael S. Tsirkin wrote: > > >> Whoa. Can't we put the resampler entry somewhere we don't need to > >> search for it? Like a kvm_kernel_irq_routing_entry, that's indexed by > >> gsi already (kvm_irq_routing_table::rt_entries[gsi]). > > > > I'm not sure why would we bother optimizing this, > > Not optimizing, simplifying. > > > but if we do, I guess we could look for the irq notifier > > which is already indexed by gsi. > > It's not, it's looked up in a list.
I'm not sure it's a simplification because to index by gsi we suddenly need to care how many gsis there are. I believe that currently means we have to assume an ioapic. Creating a dumb list is a little bit of overhead, but we get to stay blissfully unaware of the gsi implementation. Practically we're looking at a list of 4 entries, maybe a few times that when we expose more PCI root bridges to the guest. Thanks,
Alex
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