From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: Nicolin Chen <nicolinc@nvidia.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
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Subject: Re: [PATCH v3 1/5] iommu: Lock group->mutex in iommu_deferred_attach
Date: Mon, 18 Aug 2025 11:17:51 -0300 [thread overview]
Message-ID: <20250818141751.GN802098@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB5276F543286807E05FB465F58C34A@BN9PR11MB5276.namprd11.prod.outlook.com>
On Fri, Aug 15, 2025 at 08:24:57AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@nvidia.com>
> > Sent: Tuesday, August 12, 2025 6:59 AM
> >
> > The iommu_deferred_attach() is a runtime asynchronous function called by
> > iommu-dma function, which could race against other attach functions if it
> > accesses something in the dev->iommu_group.
>
> Is there a real racing scenario being observed or more theoretical?
I think the commit message should explain the actual reason this is
being done, which AFAICT because the new lockdeps added in following
patches will fail on this path otherwise.
Jason
next prev parent reply other threads:[~2025-08-18 14:17 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-11 22:59 [PATCH v3 0/5] Disable ATS via iommu during PCI resets Nicolin Chen
2025-08-11 22:59 ` [PATCH v3 1/5] iommu: Lock group->mutex in iommu_deferred_attach Nicolin Chen
2025-08-15 5:09 ` Baolu Lu
2025-08-15 8:27 ` Tian, Kevin
2025-08-15 8:24 ` Tian, Kevin
2025-08-15 19:26 ` Nicolin Chen
2025-08-18 14:17 ` Jason Gunthorpe [this message]
2025-08-18 17:45 ` Nicolin Chen
2025-08-18 18:09 ` Jason Gunthorpe
2025-08-18 18:29 ` Nicolin Chen
2025-08-11 22:59 ` [PATCH v3 2/5] iommu: Pass in gdev to __iommu_device_set_domain Nicolin Chen
2025-08-15 5:18 ` Baolu Lu
2025-08-15 8:29 ` Tian, Kevin
2025-08-11 22:59 ` [PATCH v3 3/5] iommu: Add iommu_get_domain_for_dev_locked() helper Nicolin Chen
2025-08-15 5:28 ` Baolu Lu
2025-08-15 18:48 ` Nicolin Chen
2025-08-18 14:40 ` Jason Gunthorpe
2025-08-19 2:09 ` Baolu Lu
2025-08-15 8:55 ` Tian, Kevin
2025-08-15 18:45 ` Nicolin Chen
2025-08-21 8:07 ` Tian, Kevin
2025-08-21 14:41 ` Nicolin Chen
2025-08-31 23:24 ` Nicolin Chen
2025-08-18 14:39 ` Jason Gunthorpe
2025-08-18 17:22 ` Nicolin Chen
2025-08-18 23:42 ` Jason Gunthorpe
2025-08-19 5:09 ` Nicolin Chen
2025-08-19 12:52 ` Jason Gunthorpe
2025-08-19 17:22 ` Nicolin Chen
2025-08-21 13:13 ` Jason Gunthorpe
2025-08-21 15:22 ` Nicolin Chen
2025-08-21 18:37 ` Jason Gunthorpe
2025-08-22 5:11 ` Nicolin Chen
2025-08-21 8:11 ` Tian, Kevin
2025-08-21 13:14 ` Jason Gunthorpe
2025-08-22 9:45 ` Tian, Kevin
2025-08-22 13:21 ` Jason Gunthorpe
2025-08-11 22:59 ` [PATCH v3 4/5] iommu: Introduce iommu_dev_reset_prepare() and iommu_dev_reset_done() Nicolin Chen
2025-08-15 5:49 ` Baolu Lu
2025-08-15 20:10 ` Nicolin Chen
2025-08-15 9:14 ` Tian, Kevin
2025-08-15 19:45 ` Nicolin Chen
2025-08-11 22:59 ` [PATCH v3 5/5] pci: Suspend iommu function prior to resetting a device Nicolin Chen
2025-08-19 14:12 ` Ethan Zhao
2025-08-19 21:59 ` Nicolin Chen
2025-08-20 3:18 ` Ethan Zhao
2025-08-22 6:14 ` Nicolin Chen
2025-08-21 13:07 ` Jason Gunthorpe
2025-08-22 6:35 ` Nicolin Chen
2025-08-22 14:08 ` Jason Gunthorpe
2025-08-22 18:50 ` Nicolin Chen
2025-08-28 12:51 ` Jason Gunthorpe
2025-08-28 15:08 ` Nicolin Chen
2025-08-28 18:46 ` Jason Gunthorpe
2025-08-28 19:35 ` Nicolin Chen
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