Re: [PATCH 2/2] iommu/amd: Force identity mode for selected GPUs only

On 7/24/2026 8:41 PM, Jason Gunthorpe wrote:
> On Thu, Jul 23, 2026 at 04:02:46PM -0500, Bjorn Helgaas wrote:
>> I don't think the Root Port is always passed into the guest.  From
>> 1ae8c4ce1570 ("PCI: Enable AtomicOps only if Root Port supports
>> them"):
> 
> If this device has broken support for iommu translation entirely then
> vfio is unsuably broken too. The right answer is to refuse to attach a
> paging domain to such a device, I think this patch series should be
> enhanced to include this.
> > Like a qurik that says translation is broken and then def domain is
> changed and paging attach will fail

Yeah. We can add check i domain allocation path as well.

-Vasant



> 
> Jason