[PATCH v2 07/11] vfio-iommufd: Support iommufd for physical VFIO devices

[Yi Liu]

On 2022/11/8 14:10, Nicolin Chen wrote:
> On Mon, Nov 07, 2022 at 08:52:51PM -0400, Jason Gunthorpe wrote:
> 
>> @@ -795,6 +800,10 @@ static int vfio_device_first_open(struct vfio_device *device)
>>   		ret = vfio_group_use_container(device->group);
>>   		if (ret)
>>   			goto err_module_put;
>> +	} else if (device->group->iommufd) {
>> +		ret = vfio_iommufd_bind(device, device->group->iommufd);
> 
> Here we check device->group->iommufd...
> 
>> +		if (ret)
>> +			goto err_module_put;
>>   	}
>>   
>>   	device->kvm = device->group->kvm;
>> @@ -812,6 +821,7 @@ static int vfio_device_first_open(struct vfio_device *device)
>>   	device->kvm = NULL;
>>   	if (device->group->container)
>>   		vfio_group_unuse_container(device->group);
>> +	vfio_iommufd_unbind(device);
> 
> ...yet, missing here, which could result in kernel oops.
> 
> Should probably add something similar:
> +	if (device->group->iommufd)
> +		vfio_iommufd_unbind(device);
> 
> Or should check !vdev->iommufd_device inside the ->unbind.

this check was in prior version, but removed in this version. any
special reason? Jason?

> 
>>   err_module_put:
>>   	mutex_unlock(&device->group->group_lock);
>>   	module_put(device->dev->driver->owner);
>> @@ -830,6 +840,7 @@ static void vfio_device_last_close(struct vfio_device *device)
>>   	device->kvm = NULL;
>>   	if (device->group->container)
>>   		vfio_group_unuse_container(device->group);
>> +	vfio_iommufd_unbind(device);
> 
> Ditto

-- 
Regards,
Yi Liu