Re: [PATCH 4/6] iommufd/hw_pagetable: Support allocating nested parent domain

Yi Liu
2023-09-25T06:37:40Z

On 2023/9/20 13:05, Baolu Lu wrote:
> On 9/19/23 5:25 PM, Yi Liu wrote:
>> This extends IOMMU_HWPT_ALLOC to allocate domains used as parent (stage-2)
>> in nested translation.
>>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>> ---
>>   drivers/iommu/iommufd/hw_pagetable.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/iommu/iommufd/hw_pagetable.c
>> b/drivers/iommu/iommufd/hw_pagetable.c
>> index 5be7a31cbd9c..26a8a818ffa3 100644
>> --- a/drivers/iommu/iommufd/hw_pagetable.c
>> +++ b/drivers/iommu/iommufd/hw_pagetable.c
>> @@ -83,6 +83,9 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx,
>> struct iommufd_ioas *ioas,
>>       lockdep_assert_held(&ioas->mutex);
>> +    if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ops->domain_alloc_user)
>> +        return ERR_PTR(-EOPNOTSUPP);
>> +
>>       hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE);
>>       if (IS_ERR(hwpt))
>>           return hwpt;
>> @@ -154,7 +157,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
>>       struct iommufd_ioas *ioas;
>>       int rc;
>> -    if (cmd->flags || cmd->__reserved)
>> +    if (cmd->flags & ~IOMMU_HWPT_ALLOC_NEST_PARENT || cmd->__reserved)
>>           return -EOPNOTSUPP;
>
> Need a parenthesis here, otherwise the compiler will interpret it as a
> different condition.
>
>     if ((cmd->flags & ~IOMMU_HWPT_ALLOC_NEST_PARENT) || cmd->__reserved)
>         return -EOPNOTSUPP;

ok.

--
Regards,
Yi Liu