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From: Jason Gunthorpe <jgg@nvidia.com>
To: Baolu Lu <baolu.lu@linux.intel.com>
Cc: Yi Liu <yi.l.liu@intel.com>,
	joro@8bytes.org, alex.williamson@redhat.com,
	kevin.tian@intel.com, robin.murphy@arm.com, cohuck@redhat.com,
	eric.auger@redhat.com, nicolinc@nvidia.com, kvm@vger.kernel.org,
	mjrosato@linux.ibm.com, chao.p.peng@linux.intel.com,
	yi.y.sun@linux.intel.com, peterx@redhat.com, jasowang@redhat.com,
	shameerali.kolothum.thodi@huawei.com, lulu@redhat.com,
	suravee.suthikulpanit@amd.com, iommu@lists.linux.dev,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v2 3/4] iommufd: Add IOMMU_DEVICE_GET_HW_INFO
Date: Thu, 9 Mar 2023 13:20:58 -0400	[thread overview]
Message-ID: <ZAoVemZoGpx16P9E@nvidia.com> (raw)
In-Reply-To: <6c1b221e-df8d-4b82-10e5-aa3027819d45@linux.intel.com>

On Thu, Mar 09, 2023 at 09:50:18PM +0800, Baolu Lu wrote:

> > +	if (cmd->flags || cmd->__reserved || !cmd->data_len)
> > +		return -EOPNOTSUPP;
> > +
> > +	idev = iommufd_get_device(ucmd, cmd->dev_id);
> > +	if (IS_ERR(idev))
> > +		return PTR_ERR(idev);
> > +
> > +	ops = dev_iommu_ops(idev->dev);
> > +	if (!ops || !ops->hw_info) {
> 
> dev_iommu_ops() will never return a NULL.
> 
> Need below check
> 
> 	dev->iommu && dev->iommu->iommu_dev
> 
> before dev_iommu_ops(). Perhaps something like below?
> 
> 	if (!dev->iommu || !dev->iommu->iommu_dev)
> 		return -EINVAL;

At this point the device has become owned through the ownership API,
it absolutely has to have an iommu and an ops. No need to check
anything.

Jason

  reply	other threads:[~2023-03-09 17:21 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-09  7:53 [PATCH v2 0/4] iommufd: Add iommu hardware info reporting Yi Liu
2023-03-09  7:53 ` [PATCH v2 1/4] iommu: Move dev_iommu_ops() to private header Yi Liu
2023-03-09 12:58   ` Baolu Lu
2023-03-09  7:53 ` [PATCH v2 2/4] iommu: Add new iommu op to get iommu hardware information Yi Liu
2023-03-16  8:16   ` Tian, Kevin
2023-03-16  8:30     ` Baolu Lu
2023-03-17  0:08       ` Tian, Kevin
2023-03-29  9:46     ` Liu, Yi L
2023-03-09  7:53 ` [PATCH v2 3/4] iommufd: Add IOMMU_DEVICE_GET_HW_INFO Yi Liu
2023-03-09 13:50   ` Baolu Lu
2023-03-09 17:20     ` Jason Gunthorpe [this message]
2023-03-10  8:06       ` Liu, Yi L
2023-03-16  8:23   ` Tian, Kevin
2023-03-09  7:53 ` [PATCH v2 4/4] iommufd/selftest: Add coverage for IOMMU_DEVICE_GET_HW_INFO ioctl Yi Liu
2023-03-20 12:43   ` Jason Gunthorpe
2023-03-20 12:43 ` [PATCH v2 0/4] iommufd: Add iommu hardware info reporting Jason Gunthorpe

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