CONFIG_DMAR and CONFIG_INTR_REMAP for KVM PCI Pass through

[Tim Gardner]

On 04/29/2010 02:57 PM, Andrew Mason wrote:
> Hello All,
> I was attempting to restore a previously working (with Karmic) KVM guest
> which had a PCI device passed through to it and noticed that the
> 64-server kernel has the following config.
>
>> From /boot/config-2.6.32-21-server:
>
> # CONFIG_DMAR is not set
> # CONFIG_INTR_REMAP is not set
>
>
> It is my understanding that both this options are required in order for
> PCI passthrough to work with VTd capable KVM hosts.
>
> http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM
>
> Is my understanding correct? If so was this option specifically not set
> or is it just that it hadn't been turned on since migrating to the new
> kernel ?
>
>
> Thanks in advance
> Andrew
>
>
>

We have not had CONFIG_DMAR enabled in either Karmic or Lucid because 
its still marked as being experimental.

rtg
-- 
Tim Gardner tim.gardner at canonical.com