From: Jason Gunthorpe <jgg@nvidia.com>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com,
suravee.suthikulpanit@amd.com, joro@8bytes.org,
linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
linux-arm-kernel@lists.infradead.org,
linux-tegra@vger.kernel.org, yi.l.liu@intel.com,
eric.auger@redhat.com, vasant.hegde@amd.com, jon.grimm@amd.com,
santosh.shukla@amd.com, Dhaval.Giani@amd.com,
shameerali.kolothum.thodi@huawei.com
Subject: Re: [PATCH RFCv1 07/14] iommufd: Add viommu set/unset_dev_id ops
Date: Tue, 21 May 2024 15:24:48 -0300 [thread overview]
Message-ID: <20240521182448.GN20229@nvidia.com> (raw)
In-Reply-To: <ZkQW6/OAQ8MzN6Go@nvidia.com>
On Tue, May 14, 2024 at 06:59:07PM -0700, Nicolin Chen wrote:
> So, you want a proxy S1 domain for a device to attach, in case
> of a stage-2 only setup, because an S2 domain will no longer has
> a VMID, since it's shared among viommus. In the SMMU driver case,
> an arm_smmu_domain won't have an smmu pointer, so a device can't
> attach to an S2 domain but always an nested S1 domain, right?
That seems like a simple solution to the VMID lifetime, but it means
the kernel has to decode more types of vSTE.
> > Functionally we could use that global nesting domain
> > to deliver the DEV_INVALIDATE too.
>
> If my narrative above is correct, the device is actually still
> attached to S2 domain via a proxy nested S1 domain. What cache
> do we need to invalidate except S2 mappings in this case?
qemu needs a reliable place to send the invalidation commands to (ie
what ID to provide).
If we add IOMMU_VIOMMU_INVALIDATE then the ID is the viommu id.
If we enhance IOMMU_HWPT_INVALIDATE then the ID is the identity
nesting domain.
Either case leads to the viommu object in the kernel.
I don't know if there is merit one way or the other. A more specific
API surface is nice, but the two APIs are completely duplicating.
So maybe:
#define IOMMU_VIOMMU_INVALIDATE IOMMU_HWPT_INVALIDATE
As documentation and have the kernel just detect based on the type of
the passed ID?
> > > So again, yes, it makes sense to me that we move viommu and the
> > > set_dev_id to the nested series, and then drop DEV_INVALIDATE.
> >
> > I would like to do this bit by bit. viommu is a big series on its own.
> >
> > DEV_INVALIDATE is fine, it just can't do ATS invalidation.
>
> I am not very sure about AMD.
AMD will need the same vRID -> pRID stuff and we want that to run on
the VIOMMU
> Same question: any other case can we use the DEV_INVALIDATE for?
DEV_INVALIDATE was interesting before the viommu idea because
userspace could process each invalidation command and when it reaches
ATS it would invoke the correct DEV_INVALIDATE.
With viommu we expect ATS supporting drivers to support viommu and
then to do vRID -> pRID in the other invalidation paths. In this case
I don't see a reason to do DEV_INVALIDATE right now.
> > We can add ATS invalidation after either as an enhancement as part of
> > adding the VIOMMU either as DEV_INVALIDATE or VIOMMU_INVALIDATE (or
> > both)
>
> Yea, maybe step by step like this:
>
> Part-1 VIOMMU_ALLOC and VIOMMU_ATTACH
> Part-2 VIOMMU_SET/UNSET_VDEV_ID
> Part-3 VIOMMU_INVALIDATE
> Part-4 VQUEUE_ALLOC
> ...
So we have this stuff still open:
- Identity STE with PASID (part 2b)
- IOMMU_GET_HW_INFO (part 3)
- IOMMU_HWPT_ALLOC_NEST_PARENT (part 3)
- IOMMU_HWPT_DATA_ARM_SMMUV3 (part 3)
- IOMMU_HWPT_INVALIDATE_DATA_ARM_SMMUV3
- VIOMMU_ALLOC, VIOMMU_ATTACH
- VIOMMU_INVALIDATE
- VIOMMU_SET/UNSET_VDEV_ID
- VQUEUE_ALLOC / vCMDQ
I feel like IOMMU_HWPT_INVALIDATE_DATA_ARM_SMMUV3 is a reasonable fit
to part 3. Then part 4 would be VIOMMU_ALLOC -> VIOMMU_SET/UNSET_VDEV_ID
which brings ATS support the API. vCMDQ hypervisor support would sit
on top of that with just VQUEUE?
Jason
next prev parent reply other threads:[~2024-05-21 18:24 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-13 3:46 [PATCH RFCv1 00/14] Add Tegra241 (Grace) CMDQV Support (part 2/2) Nicolin Chen
2024-04-13 3:46 ` [PATCH RFCv1 01/14] iommufd: Move iommufd_object to public iommufd header Nicolin Chen
2024-05-12 13:21 ` Jason Gunthorpe
2024-05-12 22:40 ` Nicolin Chen
2024-05-13 22:30 ` Jason Gunthorpe
2024-04-13 3:46 ` [PATCH RFCv1 02/14] iommufd: Swap _iommufd_object_alloc and __iommufd_object_alloc Nicolin Chen
2024-05-12 13:26 ` Jason Gunthorpe
2024-05-13 2:29 ` Nicolin Chen
2024-05-13 3:44 ` Nicolin Chen
2024-05-13 22:30 ` Jason Gunthorpe
2024-04-13 3:47 ` [PATCH RFCv1 03/14] iommufd: Prepare for viommu structures and functions Nicolin Chen
2024-05-12 13:42 ` Jason Gunthorpe
2024-05-13 2:35 ` Nicolin Chen
2024-04-13 3:47 ` [PATCH RFCv1 04/14] iommufd: Add struct iommufd_viommu and iommufd_viommu_ops Nicolin Chen
2024-05-12 14:03 ` Jason Gunthorpe
2024-05-13 3:34 ` Nicolin Chen
2024-05-14 15:55 ` Jason Gunthorpe
2024-05-22 8:58 ` Tian, Kevin
2024-05-22 9:57 ` Baolu Lu
2024-05-22 13:39 ` Jason Gunthorpe
2024-05-23 1:43 ` Tian, Kevin
2024-05-23 4:01 ` Nicolin Chen
2024-05-23 5:40 ` Tian, Kevin
2024-05-23 12:58 ` Jason Gunthorpe
2024-05-24 2:16 ` Tian, Kevin
2024-05-24 13:03 ` Jason Gunthorpe
2024-05-24 2:36 ` Tian, Kevin
2024-04-13 3:47 ` [PATCH RFCv1 05/14] iommufd: Add IOMMUFD_OBJ_VIOMMU and IOMMUFD_CMD_VIOMMU_ALLOC Nicolin Chen
2024-05-12 14:27 ` Jason Gunthorpe
2024-05-13 4:33 ` Nicolin Chen
2024-05-14 15:38 ` Jason Gunthorpe
2024-05-15 1:20 ` Nicolin Chen
2024-05-21 18:05 ` Jason Gunthorpe
2024-05-22 0:13 ` Nicolin Chen
2024-05-22 16:46 ` Jason Gunthorpe
2024-04-13 3:47 ` [PATCH RFCv1 06/14] iommufd/selftest: Add IOMMU_VIOMMU_ALLOC test coverage Nicolin Chen
2024-04-13 3:47 ` [PATCH RFCv1 07/14] iommufd: Add viommu set/unset_dev_id ops Nicolin Chen
2024-05-12 14:46 ` Jason Gunthorpe
2024-05-13 4:39 ` Nicolin Chen
2024-05-14 15:53 ` Jason Gunthorpe
2024-05-15 1:59 ` Nicolin Chen
2024-05-21 18:24 ` Jason Gunthorpe [this message]
2024-05-21 22:27 ` Nicolin Chen
2024-05-22 13:59 ` Jason Gunthorpe
2024-05-23 6:19 ` Tian, Kevin
2024-05-23 15:01 ` Jason Gunthorpe
2024-05-24 2:21 ` Tian, Kevin
2024-05-24 3:26 ` Nicolin Chen
2024-05-24 5:24 ` Tian, Kevin
2024-05-24 5:57 ` Nicolin Chen
2024-05-24 7:21 ` Tian, Kevin
2024-05-24 13:12 ` Jason Gunthorpe
2024-05-24 13:05 ` Jason Gunthorpe
2024-05-23 5:44 ` Tian, Kevin
2024-05-23 6:09 ` Nicolin Chen
2024-05-23 6:22 ` Tian, Kevin
2024-05-23 13:33 ` Jason Gunthorpe
2024-05-12 14:51 ` Jason Gunthorpe
2024-04-13 3:47 ` [PATCH RFCv1 08/14] iommufd: Add IOMMU_VIOMMU_SET_DEV_ID ioctl Nicolin Chen
2024-05-12 14:58 ` Jason Gunthorpe
2024-05-13 5:24 ` Nicolin Chen
2024-05-17 5:14 ` Nicolin Chen
2024-05-21 18:30 ` Jason Gunthorpe
2024-05-22 2:15 ` Nicolin Chen
2024-05-23 6:42 ` Tian, Kevin
2024-05-24 5:40 ` Nicolin Chen
2024-05-24 7:13 ` Tian, Kevin
2024-05-24 13:19 ` Jason Gunthorpe
2024-05-27 1:08 ` Tian, Kevin
2024-05-28 20:22 ` Nicolin Chen
2024-05-28 20:33 ` Nicolin Chen
2024-05-29 2:58 ` Tian, Kevin
2024-05-29 3:20 ` Nicolin Chen
2024-05-30 0:28 ` Tian, Kevin
2024-05-30 0:58 ` Nicolin Chen
2024-05-30 3:05 ` Tian, Kevin
2024-05-30 4:26 ` Nicolin Chen
2024-06-01 21:45 ` Jason Gunthorpe
2024-06-03 3:25 ` Nicolin Chen
2024-06-06 18:24 ` Jason Gunthorpe
2024-06-06 18:44 ` Nicolin Chen
2024-06-07 0:27 ` Jason Gunthorpe
2024-06-07 0:36 ` Tian, Kevin
2024-06-07 14:49 ` Jason Gunthorpe
2024-06-07 21:19 ` Nicolin Chen
2024-06-10 12:04 ` Jason Gunthorpe
2024-06-10 20:01 ` Nicolin Chen
2024-06-10 22:01 ` Jason Gunthorpe
2024-06-10 23:04 ` Nicolin Chen
2024-06-11 0:28 ` Jason Gunthorpe
2024-06-11 0:44 ` Nicolin Chen
2024-06-11 12:17 ` Jason Gunthorpe
2024-06-11 19:11 ` Nicolin Chen
2024-05-28 20:30 ` Nicolin Chen
2024-05-24 13:20 ` Jason Gunthorpe
2024-04-13 3:47 ` [PATCH RFCv1 09/14] iommufd/selftest: Add IOMMU_VIOMMU_SET_DEV_ID test coverage Nicolin Chen
2024-04-13 3:47 ` [PATCH RFCv1 10/14] iommufd/selftest: Add IOMMU_TEST_OP_MV_CHECK_DEV_ID Nicolin Chen
2024-04-13 3:47 ` [PATCH RFCv1 11/14] iommufd: Add struct iommufd_vqueue and its related viommu ops Nicolin Chen
2024-04-13 3:47 ` [PATCH RFCv1 12/14] iommufd: Add IOMMUFD_OBJ_VQUEUE and IOMMUFD_CMD_VQUEUE_ALLOC Nicolin Chen
2024-05-12 15:02 ` Jason Gunthorpe
2024-05-13 4:41 ` Nicolin Chen
2024-05-13 22:36 ` Jason Gunthorpe
2024-05-23 6:57 ` Tian, Kevin
2024-05-24 4:42 ` Nicolin Chen
2024-05-24 5:26 ` Tian, Kevin
2024-05-24 6:03 ` Nicolin Chen
2024-05-23 7:05 ` Tian, Kevin
2024-04-13 3:47 ` [PATCH RFCv1 13/14] iommufd: Add mmap infrastructure Nicolin Chen
2024-05-12 15:19 ` Jason Gunthorpe
2024-05-13 4:43 ` Nicolin Chen
2024-04-13 3:47 ` [PATCH RFCv1 14/14] iommu/tegra241-cmdqv: Add user-space use support Nicolin Chen
2024-05-22 8:40 ` [PATCH RFCv1 00/14] Add Tegra241 (Grace) CMDQV Support (part 2/2) Tian, Kevin
2024-05-22 16:48 ` Jason Gunthorpe
2024-05-22 19:47 ` Nicolin Chen
2024-05-22 23:28 ` Jason Gunthorpe
2024-05-22 23:43 ` Tian, Kevin
2024-05-23 3:09 ` Nicolin Chen
2024-05-23 12:48 ` Jason Gunthorpe
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