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From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: Nicolin Chen <nicolinc@nvidia.com>,
	"will@kernel.org" <will@kernel.org>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>,
	"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
	"Liu, Yi L" <yi.l.liu@intel.com>,
	"eric.auger@redhat.com" <eric.auger@redhat.com>,
	"vasant.hegde@amd.com" <vasant.hegde@amd.com>,
	"jon.grimm@amd.com" <jon.grimm@amd.com>,
	"santosh.shukla@amd.com" <santosh.shukla@amd.com>,
	"Dhaval.Giani@amd.com" <Dhaval.Giani@amd.com>,
	"shameerali.kolothum.thodi@huawei.com"
	<shameerali.kolothum.thodi@huawei.com>
Subject: Re: [PATCH RFCv1 07/14] iommufd: Add viommu set/unset_dev_id ops
Date: Fri, 24 May 2024 10:05:18 -0300	[thread overview]
Message-ID: <20240524130518.GR20229@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB5276A896D215E1FA61DECDC38CF52@BN9PR11MB5276.namprd11.prod.outlook.com>

On Fri, May 24, 2024 at 02:21:23AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Thursday, May 23, 2024 11:01 PM
> > 
> > On Thu, May 23, 2024 at 06:19:59AM +0000, Tian, Kevin wrote:
> > > > From: Jason Gunthorpe <jgg@nvidia.com>
> > > > Sent: Wednesday, May 22, 2024 2:25 AM
> > > >
> > > > 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.
> > > >
> > >
> > > why does ATC invalidation need to know about VMID?
> > 
> > ATC invalidation always requires a vRID to pRID translation and the
> > VIOMMU will hold that translation.
> > 
> > On vCMDQ HW and on AMD HW the vRID to pRID translation is pushed into
> > HW, and vCMDQ requires the VMID to do that.
> > 
> 
> At a quick glance VMID and vRID->pRID translation are both configurations
> of a vintf.
> 
> My impression was that vintf->vmid is added to guest cmd when it's
> about iotlb invalidation.
> 
> then vintf->sid_slots is walked when handling a guest cmd for ATC
> invalidation.
> 
> I'm not sure why the latter one requires a valid VMID to do the walking
> except it's a implementation choice made by vCMDQ?

Yeah, that is probably right. And then in iommufd we are sort of
doubling down by saying the VIOMMU object holds the S2 and the
vRID->pRID as a bundle together.

Jason

  parent reply	other threads:[~2024-05-24 13:05 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
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 [this message]
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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