Re: [PATCH V1] accel/amdxdna: Block running when IOMMU is off

[Lizhi Hou <lizhi.hou@amd.com>]

On 5/20/26 17:57, Mario Limonciello wrote:
>
>
> On 5/20/26 17:35, Lizhi Hou wrote:
>> The AIE2 device firmware requires IOMMU on.
>>
>> Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5319
>> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
>> ---
>>   drivers/accel/amdxdna/aie2_pci.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/accel/amdxdna/aie2_pci.c 
>> b/drivers/accel/amdxdna/aie2_pci.c
>> index c4d345d4c76b..22f66c7f534d 100644
>> --- a/drivers/accel/amdxdna/aie2_pci.c
>> +++ b/drivers/accel/amdxdna/aie2_pci.c
>> @@ -490,6 +490,11 @@ static int aie2_init(struct amdxdna_dev *xdna)
>>           return -EINVAL;
>>       }
>>   +    if (!xdna->group) {
>> +        XDNA_ERR(xdna, "Running without IOMMU not supported");
>> +        return -EINVAL;
>> +    }
>> +
>>       ndev = drmm_kzalloc(&xdna->ddev, sizeof(*ndev), GFP_KERNEL);
>>       if (!ndev)
>>           return -ENOMEM;
>
> I think it would be better to change the return for amdxdna_iommu_init().

amdxdna_iommu_init() is common code for all kinds of hardware. I would 
keep the check only for AIE2 now, which is known to require IOMMU on.


Lizhi

>
> This has a check that lets !xdna->group pass; which can be turned into 
> an error code instead.