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From: Jason Gunthorpe <jgg@nvidia.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	cohuck@redhat.com, iommu@lists.linux.dev,
	iommu@lists.linux-foundation.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] vfio/type1: Simplify bus_type determination
Date: Thu, 23 Jun 2022 17:50:32 -0300	[thread overview]
Message-ID: <20220623205032.GH4147@nvidia.com> (raw)
In-Reply-To: <68263bd7-4528-7acb-b11f-6b1c6c8c72ef@arm.com>

On Thu, Jun 23, 2022 at 01:23:05PM +0100, Robin Murphy wrote:

> So yes, technically we could implement an iommu_group_capable() and an
> iommu_group_domain_alloc(), which would still just internally resolve the
> IOMMU ops and instance data from a member device to perform the driver-level
> call, but once again it would be for the benefit of precisely one
> user. 

Benefit one user and come with a fairly complex locking situation to
boot.

Alex, I'd rather think about moving the type 1 code so that the iommu
attach happens during device FD creation (then we have a concrete
non-fake device), not during group FD opening.

That is the model we need for iommufd anyhow.

Jason

  reply	other threads:[~2022-06-23 20:50 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-22 12:04 [PATCH v2 1/2] vfio/type1: Simplify bus_type determination Robin Murphy
2022-06-22 12:04 ` [PATCH v2 2/2] vfio: Use device_iommu_capable() Robin Murphy
2022-06-23  1:47   ` Baolu Lu
2022-06-22 22:17 ` [PATCH v2 1/2] vfio/type1: Simplify bus_type determination Alex Williamson
2022-06-23  8:46   ` Tian, Kevin
2022-06-23 20:35     ` Alex Williamson
2022-06-23 12:23   ` Robin Murphy
2022-06-23 20:50     ` Jason Gunthorpe [this message]
2022-06-23 23:00     ` Alex Williamson
2022-06-24  1:50       ` Jason Gunthorpe
2022-06-24 14:11         ` Alex Williamson
2022-06-24 14:18           ` Jason Gunthorpe
2022-06-24 14:28             ` Alex Williamson
2022-06-24 14:56               ` Jason Gunthorpe
2022-06-24 15:12               ` Robin Murphy
2022-06-24 16:04                 ` Alex Williamson
2022-06-23  1:46 ` Baolu Lu
2022-06-23  4:32 ` kernel test robot
2022-06-24  1:52 ` Jason Gunthorpe

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