From: Jason Gunthorpe <jgg@nvidia.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Nicolin Chen <nicolinc@nvidia.com>,
kevin.tian@intel.com, tglx@linutronix.de, maz@kernel.org,
joro@8bytes.org, will@kernel.org, shuah@kernel.org,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kselftest@vger.kernel.org, eric.auger@redhat.com,
baolu.lu@linux.intel.com, yi.l.liu@intel.com,
yury.norov@gmail.com, jacob.pan@linux.microsoft.com,
patches@lists.linux.dev
Subject: Re: [PATCH v2 7/7] iommu: Turn iova_cookie to dma-iommu private pointer
Date: Fri, 21 Feb 2025 12:48:54 -0400 [thread overview]
Message-ID: <20250221164854.GO50639@nvidia.com> (raw)
In-Reply-To: <b9b4bfe3-9d2d-4009-b3d4-e179e8bccd9a@arm.com>
On Fri, Feb 21, 2025 at 03:23:22PM +0000, Robin Murphy wrote:
> Eww... What's the issue with just checking the domain type in
> iommu_put_dma_cookie()? Is is that IOMMUFD and VFIO type 1 are both doing
> their own different thing with IOMMU_DOMAIN_UNMANAGED?
Yes
> In general it seems like a bad smell to have a union in a structure with not
> enough information within that structire itself to know which union member
> is valid... :/
The concept is the opaque pointer belongs only to the caller that
allocated and owns the domain. The core iommu code should never look
at it or touch it.
The problem is with the mandatory call to dma-iommu in the free path -
dma-iommu code should never be invoked outside of VFIO and the default
domain cases.
So the little rework I sketched makes it into the caller knowing if
dma-iommu is operating that domain and then only does it call the
dma-iommu related functions, and the core code never touches the union
content.
Jason
next prev parent reply other threads:[~2025-02-21 16:50 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-20 1:31 [PATCH v2 0/7] iommu: Add MSI mapping support with nested SMMU (Part-1 core) Nicolin Chen
2025-02-20 1:31 ` [PATCH v2 1/7] genirq/msi: Store the IOMMU IOVA directly in msi_desc instead of iommu_cookie Nicolin Chen
2025-02-21 9:28 ` Thomas Gleixner
2025-02-21 11:10 ` Joerg Roedel
2025-02-21 13:41 ` Jason Gunthorpe
2025-02-21 14:00 ` Joerg Roedel
2025-02-21 14:05 ` Jason Gunthorpe
2025-02-20 1:31 ` [PATCH v2 2/7] genirq/msi: Refactor iommu_dma_compose_msi_msg() Nicolin Chen
2025-02-21 9:28 ` Thomas Gleixner
2025-02-20 1:31 ` [PATCH v2 3/7] iommu: Make iommu_dma_prepare_msi() into a generic operation Nicolin Chen
2025-02-21 15:39 ` Robin Murphy
2025-02-21 16:44 ` Jason Gunthorpe
2025-02-27 11:21 ` Robin Murphy
2025-02-27 15:32 ` Jason Gunthorpe
2025-02-27 17:46 ` Nicolin Chen
2025-02-27 19:47 ` Jason Gunthorpe
2025-02-20 1:31 ` [PATCH v2 4/7] irqchip: Have CONFIG_IRQ_MSI_IOMMU be selected by irqchips that need it Nicolin Chen
2025-02-21 9:30 ` Thomas Gleixner
2025-02-21 14:48 ` Jason Gunthorpe
2025-02-20 1:31 ` [PATCH v2 5/7] iommu: Turn fault_data to iommufd private pointer Nicolin Chen
2025-02-20 17:50 ` Jason Gunthorpe
2025-02-20 1:31 ` [PATCH v2 6/7] iommufd: Implement sw_msi support natively Nicolin Chen
2025-02-21 14:51 ` Jason Gunthorpe
2025-02-27 19:33 ` Jason Gunthorpe
2025-02-20 1:31 ` [PATCH v2 7/7] iommu: Turn iova_cookie to dma-iommu private pointer Nicolin Chen
2025-02-20 17:50 ` Jason Gunthorpe
2025-02-21 14:39 ` Jason Gunthorpe
2025-02-21 15:23 ` Robin Murphy
2025-02-21 16:48 ` Jason Gunthorpe [this message]
2025-02-26 2:25 ` Nicolin Chen
2025-02-26 17:36 ` Jason Gunthorpe
2025-02-26 18:57 ` Nicolin Chen
2025-02-26 19:18 ` Jason Gunthorpe
2025-02-21 14:59 ` [PATCH v2 0/7] iommu: Add MSI mapping support with nested SMMU (Part-1 core) Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250221164854.GO50639@nvidia.com \
--to=jgg@nvidia.com \
--cc=baolu.lu@linux.intel.com \
--cc=eric.auger@redhat.com \
--cc=iommu@lists.linux.dev \
--cc=jacob.pan@linux.microsoft.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=maz@kernel.org \
--cc=nicolinc@nvidia.com \
--cc=patches@lists.linux.dev \
--cc=robin.murphy@arm.com \
--cc=shuah@kernel.org \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
--cc=yi.l.liu@intel.com \
--cc=yury.norov@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).