Exporting PCI device

Exporting PCI device

[Lukas Hejtmanek]

Hello,

one question, if I export PCI device from Dom0 to DomU, should the device
possess the same IRQ number in both domains?

For example, I'm playing with an InfiniBand card in DomU and I can see that
lspci -v in Dom0 reports that it has IRQ #16 while in DomU it has IRQ #10
(using also lspci -v). Is this correct and possible behaviour or is it a bug
that should be fixed?

-- 
Lukáš Hejtmánek

RE: Exporting PCI device

[Tian, Kevin]

>From: Lukas Hejtmanek
>Sent: 2007年7月2日 23:16
>
>Hello,
>
>one question, if I export PCI device from Dom0 to DomU, should the
>device
>possess the same IRQ number in both domains?
>
>For example, I'm playing with an InfiniBand card in DomU and I can see
>that
>lspci -v in Dom0 reports that it has IRQ #16 while in DomU it has IRQ
>#10
>(using also lspci -v). Is this correct and possible behaviour or is it a bug
>that should be fixed?
>
>--

I think they should be same. domU doesn't have MP table and ACPI, 
and thus it then depends on information of interrupt line within PCI 
configuration space. You can see that pciback provides config field 
virtualization for interrupt line by returning dev->irq from dom0. 
Inconsistent irq number between dom0 and domU will confuse Xen 
when translating from vector into irq number.

Thanks,
Kevin