From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: "Liu, Yi L" <yi.l.liu@intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
"cohuck@redhat.com" <cohuck@redhat.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"mjrosato@linux.ibm.com" <mjrosato@linux.ibm.com>,
"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
"yi.y.sun@linux.intel.com" <yi.y.sun@linux.intel.com>,
"peterx@redhat.com" <peterx@redhat.com>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"shameerali.kolothum.thodi@huawei.com"
<shameerali.kolothum.thodi@huawei.com>,
"lulu@redhat.com" <lulu@redhat.com>,
"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-kselftest@vger.kernel.org"
<linux-kselftest@vger.kernel.org>,
"Duan, Zhenzhong" <zhenzhong.duan@intel.com>,
"Martins, Joao" <joao.m.martins@oracle.com>
Subject: Re: [PATCH v4 05/17] iommufd: Separate kernel-managed HWPT alloc/destroy/abort functions
Date: Mon, 16 Oct 2023 09:02:41 -0300 [thread overview]
Message-ID: <20231016120241.GR3952@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB52763F73D66CBBF6BEBA9B968CD7A@BN9PR11MB5276.namprd11.prod.outlook.com>
On Mon, Oct 16, 2023 at 08:26:25AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Friday, October 13, 2023 10:06 PM
> >
> > On Fri, Oct 13, 2023 at 07:13:34AM +0000, Tian, Kevin wrote:
> > > > From: Jason Gunthorpe <jgg@nvidia.com>
> > > > Sent: Friday, October 13, 2023 3:10 AM
> > > >
> > > > Also, we probably should feed enforce_cache_coherency through the
> > > > alloc_hwpt uapi and not try to autodetect it..
> > > >
> > >
> > > In the past we had a long discussion about this with the conclusion
> > > that user opt is the ideal model but it's fine to stay with autodetect
> > > and existing vfio/kvm contract for coherency detection until we
> > > see a real demand for user opt.
> > >
> > > Is there anything new which changes your mind to have user opt now?
> >
> > I guess, I was just looking at the complexity it brings to keep that
> > working.
> >
>
> vfio_file_enforced_coherent() currently just looks at device_iommu_capable()
> and can be called before attach, assuming an autodetect model.
>
> moving away from autodetect would need a new contract which I hesitate
> to bother with at this point.
I think that is fine, we are not enabling new behaviors where qemu can
directly control the wbinvd support. If we want to do that it can be
done more directly.
If the vmm sees a coherent device and does not turn on enforced
coherency then it will get a broken wbinvd and be sad. Since this is
all in the userspace vt-d iommu driver, it can just do the right thing
anyhow.
Jason
next prev parent reply other threads:[~2023-10-16 12:02 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-21 7:51 [PATCH v4 00/17] iommufd: Add nesting infrastructure Yi Liu
2023-09-21 7:51 ` [PATCH v4 01/17] iommu: Add hwpt_type with user_data for domain_alloc_user op Yi Liu
2023-09-21 12:10 ` Baolu Lu
2023-09-21 20:58 ` Nicolin Chen
2023-09-25 13:05 ` Jason Gunthorpe
2023-09-25 18:17 ` Nicolin Chen
2023-09-25 6:22 ` Yi Liu
2023-09-25 8:01 ` Baolu Lu
2023-09-25 13:00 ` Jason Gunthorpe
2023-09-21 12:12 ` Baolu Lu
2023-09-21 16:44 ` Jason Gunthorpe
2023-09-22 9:47 ` Robin Murphy
2023-09-25 6:17 ` Yi Liu
2023-09-25 12:59 ` Jason Gunthorpe
2023-09-26 6:37 ` Tian, Kevin
2023-09-26 16:29 ` Jason Gunthorpe
2023-09-27 1:08 ` Tian, Kevin
2023-10-07 9:38 ` Yi Liu
2023-09-26 6:56 ` Tian, Kevin
2023-10-12 9:12 ` Yi Liu
2023-10-13 11:42 ` Yi Liu
2023-10-13 22:22 ` Nicolin Chen
2023-10-10 16:58 ` Jason Gunthorpe
2023-10-12 9:11 ` Yi Liu
2023-10-12 13:39 ` Jason Gunthorpe
2023-10-13 4:33 ` Yi Liu
2023-10-13 14:04 ` Jason Gunthorpe
2023-10-13 17:56 ` Nicolin Chen
2023-10-16 3:28 ` Yi Liu
2023-10-16 11:54 ` Jason Gunthorpe
2023-10-16 18:17 ` Nicolin Chen
2023-10-17 8:51 ` Yi Liu
2023-10-17 9:28 ` Tian, Kevin
2023-10-18 6:12 ` Yi Liu
2023-10-18 16:37 ` Jason Gunthorpe
2023-10-18 16:51 ` Nicolin Chen
2023-10-13 0:34 ` Nicolin Chen
2023-10-13 14:03 ` Jason Gunthorpe
2023-09-21 7:51 ` [PATCH v4 02/17] iommu: Add nested domain support Yi Liu
2023-10-10 17:21 ` Jason Gunthorpe
2023-10-12 9:13 ` Yi Liu
2023-10-14 0:47 ` Nicolin Chen
2023-09-21 7:51 ` [PATCH v4 03/17] iommufd: Unite all kernel-managed members into a struct Yi Liu
2023-09-26 7:46 ` Tian, Kevin
2023-10-07 10:08 ` Yan Zhao
2023-10-09 4:13 ` Yi Liu
2023-10-09 5:13 ` Yan Zhao
2023-10-10 3:26 ` Yi Liu
2023-09-21 7:51 ` [PATCH v4 04/17] iommufd: Pass in hwpt_type/user_data to iommufd_hw_pagetable_alloc() Yi Liu
2023-09-21 7:51 ` [PATCH v4 05/17] iommufd: Separate kernel-managed HWPT alloc/destroy/abort functions Yi Liu
2023-09-26 7:57 ` Tian, Kevin
2023-10-10 18:49 ` Jason Gunthorpe
2023-10-12 19:09 ` Jason Gunthorpe
2023-10-13 7:13 ` Tian, Kevin
2023-10-13 14:05 ` Jason Gunthorpe
2023-10-16 8:26 ` Tian, Kevin
2023-10-16 12:02 ` Jason Gunthorpe [this message]
2023-09-21 7:51 ` [PATCH v4 06/17] iommufd: Add shared alloc_fn function pointer and mutex pointer Yi Liu
2023-09-21 7:51 ` [PATCH v4 07/17] iommufd: Add user-managed hw_pagetable support Yi Liu
2023-09-26 8:14 ` Tian, Kevin
2023-10-14 0:08 ` Nicolin Chen
2023-09-21 7:51 ` [PATCH v4 08/17] iommufd: Always setup MSI and anforce cc on kernel-managed domains Yi Liu
2023-09-26 8:16 ` Tian, Kevin
2023-10-14 0:44 ` Nicolin Chen
2023-10-16 8:48 ` Tian, Kevin
2023-10-16 11:57 ` Jason Gunthorpe
2023-10-17 8:52 ` Tian, Kevin
2023-10-17 15:53 ` Jason Gunthorpe
2023-10-17 19:58 ` Nicolin Chen
2023-10-18 16:51 ` Jason Gunthorpe
2023-10-19 1:56 ` Tian, Kevin
2023-10-19 23:53 ` Jason Gunthorpe
2023-10-20 2:43 ` Tian, Kevin
2023-10-20 13:55 ` Jason Gunthorpe
2023-10-20 18:59 ` Nicolin Chen
2023-10-21 16:38 ` Jason Gunthorpe
2023-10-23 0:18 ` Nicolin Chen
2023-10-23 2:53 ` Tian, Kevin
2023-10-23 18:42 ` Nicolin Chen
2023-10-23 13:59 ` Jason Gunthorpe
2023-10-23 18:49 ` Nicolin Chen
2023-10-18 2:32 ` Baolu Lu
2023-10-17 9:05 ` Tian, Kevin
2023-09-21 7:51 ` [PATCH v4 09/17] iommufd/device: Add helpers to enforce/remove device reserved regions Yi Liu
2023-10-07 7:20 ` Yan Zhao
2023-10-07 9:27 ` Nicolin Chen
2023-09-21 7:51 ` [PATCH v4 10/17] iommufd: Support IOMMU_HWPT_ALLOC allocation with user data Yi Liu
2023-10-13 15:19 ` Jason Gunthorpe
2023-10-13 20:58 ` Nicolin Chen
2023-10-14 0:07 ` Jason Gunthorpe
2023-10-14 0:51 ` Nicolin Chen
2023-10-16 7:03 ` Yi Liu
2023-10-16 11:59 ` Jason Gunthorpe
2023-10-16 18:44 ` Nicolin Chen
2023-10-17 8:55 ` Yi Liu
2023-10-17 15:50 ` Jason Gunthorpe
2023-10-17 19:32 ` Nicolin Chen
2023-09-21 7:51 ` [PATCH v4 11/17] iommufd: Add IOMMU_HWPT_INVALIDATE Yi Liu
2023-09-21 7:51 ` [PATCH v4 12/17] iommufd/selftest: Rework TEST_LENGTH to test min_size explicitly Yi Liu
2023-09-21 7:51 ` [PATCH v4 13/17] iommufd/selftest: Add nested domain allocation for mock domain Yi Liu
2023-09-21 7:51 ` [PATCH v4 14/17] iommufd/selftest: Add coverage for IOMMU_HWPT_ALLOC with nested HWPTs Yi Liu
2023-09-21 7:51 ` [PATCH v4 15/17] iommufd/selftest: Add mock_domain_cache_invalidate_user support Yi Liu
2023-09-21 7:51 ` [PATCH v4 16/17] iommufd/selftest: Add IOMMU_TEST_OP_MD_CHECK_IOTLB test op Yi Liu
2023-09-21 7:51 ` [PATCH v4 17/17] iommufd/selftest: Add coverage for IOMMU_HWPT_INVALIDATE ioctl Yi Liu
2023-10-10 16:53 ` [PATCH v4 00/17] iommufd: Add nesting infrastructure Jason Gunthorpe
2023-10-12 8:45 ` Yi Liu
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