Re: [RFC v2 07/11] vfio: Swap order of vfio_device_container_register() and open_device()

From: Yi Liu <yi.l.liu@intel.com>
To: "Tian, Kevin" <kevin.tian@intel.com>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	"jgg@nvidia.com" <jgg@nvidia.com>
Cc: "eric.auger@redhat.com" <eric.auger@redhat.com>,
	"cohuck@redhat.com" <cohuck@redhat.com>,
	"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
	"yi.y.sun@linux.intel.com" <yi.y.sun@linux.intel.com>,
	"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
	"mjrosato@linux.ibm.com" <mjrosato@linux.ibm.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [RFC v2 07/11] vfio: Swap order of vfio_device_container_register() and open_device()
Date: Mon, 28 Nov 2022 17:28:22 +0800	[thread overview]
Message-ID: <f983da4e-6986-c379-0672-8d76dc72d8bf@intel.com> (raw)
In-Reply-To: <BN9PR11MB527610A799BEDD4FAD79571A8C139@BN9PR11MB5276.namprd11.prod.outlook.com>

On 2022/11/28 16:27, Tian, Kevin wrote:
>> From: Liu, Yi L <yi.l.liu@intel.com>
>> Sent: Thursday, November 24, 2022 8:27 PM
>>
>> This makes the DMA unmap callback registration to container be consistent
>> across the vfio iommufd compat mode and the legacy container mode.
>>
>> In the vfio iommufd compat mode, this registration is done in the
>> vfio_iommufd_bind() when creating access which has an unmap callback.
>> This
>> is prior to calling the open_device() op provided by mdev driver. While,
>> in the vfio legacy mode, the registration is done by
>> vfio_device_container_register() and it is after open_device(). By swapping
>> the order of vfio_device_container_register() and open_device(), the two
>> modes have the consistent order for the DMA unmap callback registration.
> 
> let's mark out that existing drivers have been converted to be OK with
> this order swap in Jason's series.

sure.

>>
>> This also prepares for further splitting group specific code.
>>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> 
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>

-- 
Regards,
Yi Liu