Re: Remaining passthrough/VT-d tasks list

[Avi Kivity <avi@redhat.com>]

Tian, Kevin wrote:
>>
>> No. Maybe the Neocleus polarity trick (which also reduces performance).
>>     
>
> To my knowledge, Neocleus polarity trick can't solve this isolation
> issue, which just provides one effecient way to track assertion/deassertion
> transition on the irq line. For example, reverse polarity when receiving an
> instance, and then a new irq instance would occur when all devices de-
> assert on shared irq line, and then recover the polarity. In your concerned
> case where guest driver misbehaves, this polarity trick can't work neither
> as one device always asserts the line.
>   

You're right, I didn't think it through.

If there was a standard way to mask pci irqs, it might have worked, but
there isn't, unfortunately.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.