From: "Tian, Kevin" <kevin.tian@intel.com>
To: Baolu Lu <baolu.lu@linux.intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"jgg@nvidia.com" <jgg@nvidia.com>
Cc: "alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"Duan, Zhenzhong" <zhenzhong.duan@intel.com>,
"Pan, Jacob jun" <jacob.jun.pan@intel.com>
Subject: RE: [PATCH v2 05/12] iommu: Allow iommu driver to populate the max_pasids
Date: Wed, 17 Apr 2024 08:49:11 +0000 [thread overview]
Message-ID: <BN9PR11MB52766AFD83D662181A4AE09E8C0F2@BN9PR11MB5276.namprd11.prod.outlook.com> (raw)
In-Reply-To: <ef76c9bc-cafb-43a8-9b1c-f832043b8330@linux.intel.com>
> From: Baolu Lu <baolu.lu@linux.intel.com>
> Sent: Monday, April 15, 2024 1:42 PM
>
> On 4/12/24 4:15 PM, Yi Liu wrote:
> > Today, the iommu layer gets the max_pasids by pci_max_pasids() or
> reading
> > the "pasid-num-bits" property. This requires the non-PCI devices to have a
> > "pasid-num-bits" property. Like the mock device used in iommufd selftest,
> > otherwise the max_pasids check would fail in iommu layer.
> >
> > While there is an alternative, the iommu layer can allow the iommu driver
> > to set the max_pasids in its probe_device() callback and populate it. This
> > is simpler and has no impact on the existing cases.
> >
> > Suggested-by: Jason Gunthorpe<jgg@nvidia.com>
> > Signed-off-by: Yi Liu<yi.l.liu@intel.com>
> > ---
> > drivers/iommu/iommu.c | 9 +++++----
> > 1 file changed, 5 insertions(+), 4 deletions(-)
>
> The code does not appear to match the commit message here.
>
> The code in change is a refactoring by folding the max_pasid assignment
> into its helper. However, the commit message suggests a desire to expose
> some kind of kAPI for device drivers.
>
it's not about exposing a new kAPI. Instead it allows the driver to
manually set dev->iommu->max_pasids before calling
iommu_init_device(). kind of another contract to convey the
max pasid.
But as how you are confused, I prefer to defining a "pasid-num-bits"
property in the mock driver. It's easier to understand.
next prev parent reply other threads:[~2024-04-17 8:49 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-12 8:15 [PATCH v2 00/12] iommufd support pasid attach/replace Yi Liu
2024-04-12 8:15 ` [PATCH v2 01/12] iommu: Pass old domain to set_dev_pasid op Yi Liu
2024-04-15 5:32 ` Baolu Lu
2024-04-15 11:54 ` Jason Gunthorpe
2024-04-16 2:07 ` Baolu Lu
2024-04-16 17:47 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 02/12] iommu: Introduce a replace API for device pasid Yi Liu
2024-04-16 3:01 ` Duan, Zhenzhong
2024-04-16 9:18 ` Yi Liu
2024-04-17 8:44 ` Tian, Kevin
2024-04-17 12:17 ` Jason Gunthorpe
2024-04-18 0:08 ` Tian, Kevin
2024-04-29 13:55 ` Jason Gunthorpe
2024-04-30 5:00 ` Yi Liu
2024-04-30 12:26 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 03/12] iommufd: replace attach_fn with a structure Yi Liu
2024-04-12 8:15 ` [PATCH v2 04/12] iommufd: Support attach/replace hwpt per pasid Yi Liu
2024-04-29 13:56 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 05/12] iommu: Allow iommu driver to populate the max_pasids Yi Liu
2024-04-15 5:41 ` Baolu Lu
2024-04-17 8:49 ` Tian, Kevin [this message]
2024-04-20 5:45 ` Yi Liu
2024-04-22 11:52 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 06/12] iommufd/selftest: Add set_dev_pasid and remove_dev_pasid in mock iommu Yi Liu
2024-04-12 8:15 ` [PATCH v2 07/12] iommufd/selftest: Add a helper to get test device Yi Liu
2024-04-12 8:15 ` [PATCH v2 08/12] iommufd/selftest: Add test ops to test pasid attach/detach Yi Liu
2024-04-12 8:15 ` [PATCH v2 09/12] iommufd/selftest: Add coverage for iommufd " Yi Liu
2024-04-12 8:15 ` [PATCH v2 10/12] iommu/vt-d: Return if no dev_pasid is found in domain Yi Liu
2024-04-15 6:04 ` Baolu Lu
2024-04-16 9:21 ` Yi Liu
2024-04-17 2:30 ` Baolu Lu
2024-04-17 3:48 ` Yi Liu
2024-04-17 9:03 ` Tian, Kevin
2024-04-17 9:36 ` Yi Liu
2024-04-12 8:15 ` [PATCH v2 11/12] iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement Yi Liu
2024-04-17 9:19 ` Tian, Kevin
2024-04-17 9:35 ` Yi Liu
2024-04-17 12:19 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 12/12] iommu/vt-d: Add set_dev_pasid callback for nested domain Yi Liu
2024-04-17 9:25 ` Tian, Kevin
2024-04-30 9:19 ` Yi Liu
2024-05-06 7:42 ` Baolu Lu
2024-05-06 13:36 ` Jason Gunthorpe
2024-05-07 2:28 ` Yi Liu
2024-05-07 15:18 ` Jason Gunthorpe
2024-05-08 6:10 ` Yi Liu
2024-05-08 12:25 ` Jason Gunthorpe
2024-05-08 13:26 ` Yi Liu
2024-05-08 14:11 ` Jason Gunthorpe
2024-05-09 14:22 ` Liu, Yi L
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