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Date: Thu, 25 Jan 2024 11:52:57 -0400
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Cc: iommu@lists.linux.dev, linuxppc-dev@lists.ozlabs.org,
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	vaibhav@linux.ibm.com
Subject: Re: [PATCH 2/2] iommu: Fix the domain type checks when
 default_domain is set
Message-ID: <20240125155257.GX50608@ziepe.ca>
References: <170618450592.3805.8216395093813382208.stgit@ltcd48-lp2.aus.stglab.ibm.com>
 <170618452753.3805.4425669653666211728.stgit@ltcd48-lp2.aus.stglab.ibm.com>
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On Thu, Jan 25, 2024 at 06:08:52AM -0600, Shivaprasad G Bhat wrote:
> On PPC64, the iommu_ops.def_domain_type() is not defined and
> CONFIG_IOMMU_DMA not enabled. With commit 0f6a90436a57 ("iommu: Do not
> use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled"), the
> iommu_get_default_domain_type() return IOMMU_DOMAIN_IDENTITY. With
> commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove
> set_platform_dma_ops"), the defaule_domain is set wih the type being
> PLATFORM. With these two changes, iommu_group_alloc_default_domain()
> ends up returning the NULL(with recent changes, ERR_PTR(-EINVAL))
> leading to iommu_probe_device() failure and the device has no
> iommu_group set in effect. Subsequently, the bind to vfio(VFIO_IOMMU)
> fail as the iommu_group is not set for the device.
> 
> Make the iommu_get_default_domain_type() to take default_domain->type
> into consideration along with default_domain_type() and fix
> iommu_group_alloc_default_domain() to not error out if the requested
> type is same as default domain type.
> 
> Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
> Fixes: 0f6a90436a57 ("iommu: Do not use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled")
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---
>  drivers/iommu/iommu.c |   14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)

Are you OK with this version?

https://lore.kernel.org/linux-iommu/20240123174905.GS50608@ziepe.ca/

?

I think it does the same thing

Jason