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Re: [Xen-devel] HVM windows - PCI IRQ firing on both CPU's

To: James Harper <james.harper@xxxxxxxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] HVM windows - PCI IRQ firing on both CPU's
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Mon, 18 Aug 2008 13:26:50 +0100
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On 18/8/08 13:19, "James Harper" <james.harper@xxxxxxxxxxxxxxxx> wrote:

> Just so I understand, even if I see the IRQ on CPU1, I should always
> treat it as if it came in on CPU0?

Yes. Only vcpu0's event-channel logic is wired into the virtual PIC/IOAPIC.
Even if the IOAPIC then forwards the interrupt to a different VCPU, it's
still vcpu0's event-channel status that initiated the interrupt. Other
vcpus' event-channel statuses do not cause interrupts in HVM.

> The lack of that would explain what I'm seeing.

It sure would.

 -- Keir

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