On Mon, Feb 17, 2014 at 02:38:09PM -0500, Gabriel L. Somlo wrote: > Oh, I think I'm starting to comprehend the problem here. The bits of > "*irq_state" are indexed by "irq_source_id", which is dynamically > assigned by kvm_request_irq_source_id(). > > So, doing the OR thing when assuming always-active-high makes > sense. Doing AND based on an active-low assumption doesn't make > sense, because there could ALWAYS be 0 bits that just weren't > allocated (yet), and I'm having trouble imagining how I'd keep > track of where the current allocation boundary is in a sane way :)
Hmm, I thought maybe I could use kvm->arch.irq_sources_bitmap, but that's global across the whole VM, whereas irq_state belongs to one given GSI. So, the per-GSI bitmap is sparse, so it's at least as bad as I thought earlier, if not worse :) Am I missing anything that would put this in a better light ? Thanks, --Gabriel
