From: "Liu, Yi L" <yi.l.liu@intel.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Baolu Lu <baolu.lu@linux.intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"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 12/12] iommu/vt-d: Add set_dev_pasid callback for nested domain
Date: Thu, 9 May 2024 14:22:00 +0000 [thread overview]
Message-ID: <DS0PR11MB752930FF648A3DC511183568C3E62@DS0PR11MB7529.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20240508141156.GJ4650@nvidia.com>
> From: Jason Gunthorpe <jgg@nvidia.com>
>
> On Wed, May 08, 2024 at 09:26:47PM +0800, Yi Liu wrote:
> > On 2024/5/8 20:25, Jason Gunthorpe wrote:
> > > On Wed, May 08, 2024 at 02:10:05PM +0800, Yi Liu wrote:
> > > > On 2024/5/7 23:18, Jason Gunthorpe wrote:
> > > > > On Tue, May 07, 2024 at 10:28:34AM +0800, Yi Liu wrote:
> > > > > > > > We still need something to do before we can safely remove this check.
> > > > > > > > All the domain allocation interfaces should eventually have the device
> > > > > > > > pointer as the input, and all domain attributions could be initialized
> > > > > > > > during domain allocation. In the attach paths, it should return -EINVAL
> > > > > > > > directly if the domain is not compatible with the iommu for the device.
> > > > > > >
> > > > > > > Yes, and this is already true for PASID.
> > > > > >
> > > > > > I'm not quite get why it is already true for PASID. I think Baolu's remark
> > > > > > is general to domains attached to either RID or PASID.
> > > > > >
> > > > > > > I feel we could reasonably insist that domanis used with PASID are
> > > > > > > allocated with a non-NULL dev.
> > > > > >
> > > > > > Any special reason for this disclaim?
> > > > >
> > > > > If it makes the driver easier, why not?
> > > >
> > > > yep.
> > > >
> > > > > PASID is special since PASID is barely used, we could insist that
> > > > > new PASID users also use the new domian_alloc API.
> > > >
> > > > Ok. I have one doubt on how to make it in iommufd core. Shall the iommufd
> > > > core call ops->domain_alloc_paging() directly or still call
> > > > ops->domain_alloc_user() while ops->domain_alloc_user() flows into the
> > > > paging domain allocation with non-null dev?
> > >
> > > I mostly figured we'd need a new iommu_domain_alloc_dev() sort of
> > > thing? VFIO should be changed over too.
> >
> > Would this new iommu-domain_alloc_dev() have flags and user_data
> > input?
>
> No, it would be an in-kernel replacement for the existing API.
Ok.
> > As below code snippet, the existing iommufd core uses domain_alloc_user
> > op to allocate the s2 domain (paging domain), and will fall back to
> > iommu_domain_alloc() only if the domain_alloc_user op does not exist. The
>
> Oh, right. Yeah we built it like that so that drivers would have
> consistency that iommufd always uses the _user version if it exists.
Yep. This means for the iommu drivers that have implemented
domain_alloc_user op, it would not call into the new iommu_domain_alloc_dev().
So I would need to make the intel domain_alloc_user op allocate paging domain
with non-dev as well.
> > typical reason is to use domain_alloc_user op is to allocate a paging
> > domain with NESTED_PARENT flag. I suppose the new iommu_domain_alloc_dev()
> > shall allow allocating s2 domain with NESTED_PARENT as well. right?
>
> No, it is just a simple replacement for iommu_domain_alloc() that does
> exactly the same thing. We don't have any in-kernel use for anything
> more fancy than a simple domain right now.
Yes.
Regards,
Yi Liu
prev parent reply other threads:[~2024-05-09 14:22 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
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 [this message]
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