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    SubjectRe: [PATCH RFC] kvm: enable irq injection from interrupt context
      On 09/16/2010 02:57 PM, Michael S. Tsirkin wrote:
    > >
    > > > > If you want to split parts that asserts irq and de-asserts it then we
    > > > > should have irqfd that tracks line status and knows interrupt line
    > > > > polarity.
    > > >
    > > > Yes, it can know about polarity even though I think it's cleaner to do this
    > > > per gsi. But it can not track line status as line is shared with
    > > > other devices.
    > > It should track only device's line status.
    >
    > There is no such thing as device's line status on real hardware, either.
    > Devices do not drive INT# high: they drive it low (all the time)
    > or do not drive it at all.
    >

    That's just an implementation detail. Devices either assert INT# or
    they do not. Tying the wires together constitutes an AND gate. This
    gate has to be modelled somewhere, currently it's in qemu's pci emulation.

    --
    error compiling committee.c: too many arguments to function



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