From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir@xen.org>
Subject: Re: [PATCH] IRQ: manually EOI migrating line interrupts
Date: Tue, 30 Aug 2011 15:38:53 +0100
Message-ID: <CA82B48D.30D07%keir@xen.org>
References: <4E5CF393.10903@citrix.com>
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To: Andrew Cooper <andrew.cooper3@citrix.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
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On 30/08/2011 15:28, "Andrew Cooper" <andrew.cooper3@citrix.com> wrote:

>> @@ -1739,6 +1739,14 @@ static void end_level_ioapic_irq (unsign
>>   */
>>      i = IO_APIC_VECTOR(irq);
>>  
>> +    /* Manually EOI the old vector if we are moving to the new */
>> +    if ( vector && i != vector )
>> +    {
>> +        int ioapic;
>> +        for (ioapic = 0; ioapic < nr_ioapics; ioapic++)
>> +            io_apic_eoi(ioapic, i);
>> +    }
>> +

I don't know whether it's worth the effort, but we ought to be able to do
better than this and send EOI to exactly the correct IO-APIC. I think
irq=gsi here? And we should know the gsi_base of every IO-APIC, so we can
work out in fact which pin of which IO-APIC needs clobbering?

 -- Keir