On 2021/2/2 20:58, Robin Murphy wrote:
> On 2021-02-02 08:53, Keqian Zhu wrote:
>> Signed-off-by: Keqian Zhu <[email protected]>
>> ---
>> include/linux/iommu.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 77e561ed57fd..e8f2efae212b 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -68,7 +68,7 @@ struct iommu_domain_geometry {
>> * devices
>> * IOMMU_DOMAIN_IDENTITY - DMA addresses are system physical
>> addresses
>> * IOMMU_DOMAIN_UNMANAGED - DMA mappings managed by IOMMU-API user,
>> used
>> - * for VMs
>> + * for VMs or userspace driver frameworks
>
> Given that "VMs" effectively has to mean VFIO, doesn't it effectively already
> imply other uses of VFIO anyway? Unmanaged domains are also used in other
> subsystems/drivers inside the kernel and we're not naming those, so I don't
> see that it's particularly helpful to specifically call out one more VFIO
> use-case.
>
> Perhaps the current wording could be generalised a little more, but we
> certainly don't want to start trying to maintain an exhaustive list of users
> here...
Yep, a more generalised description is better. After I have a look at all the
use cases...
Thanks,
Keqian
>
> Robin.
>
>> * IOMMU_DOMAIN_DMA - Internally used for DMA-API implementations.
>> * This flag allows IOMMU drivers to implement
>> * certain optimizations for these domains
>>
> .
>
