From: Joerg Roedel <joro@8bytes.org>
To: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>,
Will Deacon <will.deacon@arm.com>,
iommu@lists.linux-foundation.org,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH RFC 0/4] iommu: Add support to change default domain of a group
Date: Mon, 22 Jul 2019 16:41:02 +0200 [thread overview]
Message-ID: <20190722144102.GC12009@8bytes.org> (raw)
In-Reply-To: <cover.1562116655.git.sai.praneeth.prakhya@intel.com>
On Tue, Jul 02, 2019 at 06:53:58PM -0700, Sai Praneeth Prakhya wrote:
> Assume a use case where-in the priviliged user would want to use the device in
> pass-through mode when the device is used for host but would want to switch to
> dma protected mode when switching for VFIO in user space. Presently, this is not
> supported and hence add support to change default domain of a group dynamically.
VFIO does it's own iommu magic with the device and moves the group out
of the default domain, so that doesn't sound like a valid use-case. More
valid would be something like putting a device into passthrough mode to
improve performance, or do you have other valid use-cases in mind?
Regards,
Joerg
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next prev parent reply other threads:[~2019-07-22 14:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-03 1:53 [PATCH RFC 0/4] iommu: Add support to change default domain of a group Sai Praneeth Prakhya
2019-07-03 1:53 ` [PATCH RFC 1/4] iommu/vt-d: Modify device_def_domain_type() to use at runtime Sai Praneeth Prakhya
2019-07-22 15:11 ` Joerg Roedel
2019-07-26 6:47 ` Prakhya, Sai Praneeth
2019-07-03 1:54 ` [PATCH RFC 2/4] iommu: Add device_def_domain_type() call back function to iommu_ops Sai Praneeth Prakhya
2019-07-03 1:54 ` [PATCH RFC 3/4] iommu: Add support to change default domain of a group Sai Praneeth Prakhya
2019-07-03 1:54 ` [PATCH RFC 4/4] iommu: Document usage of "/sys/kernel/iommu_groups/<grp_id>/type" file Sai Praneeth Prakhya
2019-07-22 14:41 ` Joerg Roedel [this message]
2019-07-26 6:44 ` [PATCH RFC 0/4] iommu: Add support to change default domain of a group Prakhya, Sai Praneeth
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