Re: [PATCH 1/1] iommu/vt-d: Assign owner to the static identity domain

[Dave Jiang <dave.jiang@intel.com>]

On 4/22/25 12:54 AM, Lu Baolu wrote:
> The idxd driver attaches the default domain to a PASID of the device to
> perform kernel DMA using that PASID. The domain is attached to the
> device's PASID through iommu_attach_device_pasid(), which checks if the
> domain->owner matches the iommu_ops retrieved from the device. If they
> do not match, it returns a failure.
> 
>         if (ops != domain->owner || pasid == IOMMU_NO_PASID)
>                 return -EINVAL;
> 
> The static identity domain implemented by the intel iommu driver doesn't
> specify the domain owner. Therefore, kernel DMA with PASID doesn't work
> for the idxd driver if the device translation mode is set to passthrough.
> 
> Fix this by specifying the domain owner for the static identity domain.
> 
> Fixes: 2031c469f816 ("iommu/vt-d: Add support for static identity domain")
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220031
> Cc: stable@vger.kernel.org
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/iommu/intel/iommu.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index cb0b993bebb4..63c9c97ccf69 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4385,6 +4385,7 @@ static struct iommu_domain identity_domain = {
>  		.attach_dev	= identity_domain_attach_dev,
>  		.set_dev_pasid	= identity_domain_set_dev_pasid,
>  	},
> +	.owner = &intel_iommu_ops,
>  };
>  
>  const struct iommu_ops intel_iommu_ops = {