From: "Tian, Kevin" <kevin.tian@intel.com>
To: Nicolin Chen <nicolinc@nvidia.com>,
"jgg@nvidia.com" <jgg@nvidia.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"will@kernel.org" <will@kernel.org>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"shuah@kernel.org" <shuah@kernel.org>
Cc: "Liu, Yi L" <yi.l.liu@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kselftest@vger.kernel.org"
<linux-kselftest@vger.kernel.org>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>
Subject: RE: [PATCH v1 5/8] iommufd: Add replace support in iommufd_access_set_ioas()
Date: Fri, 3 Feb 2023 10:10:45 +0000 [thread overview]
Message-ID: <BN9PR11MB5276D06D3F9AA6202E20F8E68CD79@BN9PR11MB5276.namprd11.prod.outlook.com> (raw)
In-Reply-To: <bfe5aed6d354ef547979f0b256c8a3f9bd5b223b.1675320212.git.nicolinc@nvidia.com>
> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Thursday, February 2, 2023 3:05 PM
>
> Support an access->ioas replacement in iommufd_access_set_ioas(), which
> sets the access->ioas to NULL provisionally so that any further incoming
> iommufd_access_pin_pages() callback can be blocked.
>
> Then, call access->ops->unmap() to clean up the entire iopt. To allow an
> iommufd_access_unpin_pages() callback to happen via this unmap() call,
> add an ioas_unpin pointer so the unpin routine won't be affected by the
> "access->ioas = NULL" trick above.
>
> Also, a vdev without an ops->dma_unmap implementation cannot replace its
> access->ioas pointer. So add an iommufd_access_ioas_is_attached() helper
> to sanity that.
>
Presumably a driver which doesn't implement ops->dma_unmap shouldn't
be allowed to do pin/unpin. But it could use vfio_dma_rw() to access an
iova range. In the latter case I don't see why replace cannot work.
Probably what's required here is to deny !ops->dma_unmap in
vfio_pin/unpin_pages then making here replace always allowed?
next prev parent reply other threads:[~2023-02-03 10:11 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-02 7:05 [PATCH v1 0/8] Add IO page table replacement support Nicolin Chen
2023-02-02 7:05 ` [PATCH v1 1/8] iommu: Move dev_iommu_ops() to private header Nicolin Chen
2023-02-02 7:05 ` [PATCH v1 2/8] iommu: Introduce a new iommu_group_replace_domain() API Nicolin Chen
2023-02-02 10:21 ` Baolu Lu
2023-02-02 19:14 ` Nicolin Chen
2023-02-03 1:33 ` Baolu Lu
2023-02-03 1:41 ` Nicolin Chen
2023-02-03 2:35 ` Baolu Lu
2023-02-03 8:26 ` Tian, Kevin
2023-02-03 15:03 ` Jason Gunthorpe
2023-02-03 17:53 ` Nicolin Chen
2023-02-06 6:57 ` Tian, Kevin
2023-02-06 13:25 ` Jason Gunthorpe
2023-02-07 0:32 ` Tian, Kevin
2023-02-07 12:22 ` Jason Gunthorpe
2023-02-08 4:25 ` Tian, Kevin
2023-02-08 12:42 ` Jason Gunthorpe
2023-02-07 19:16 ` Nicolin Chen
2023-02-03 17:45 ` Nicolin Chen
2023-02-06 6:40 ` Tian, Kevin
2023-02-02 7:05 ` [PATCH v1 3/8] iommufd: Create access in vfio_iommufd_emulated_bind() Nicolin Chen
2023-02-03 9:23 ` Tian, Kevin
2023-02-03 9:28 ` Tian, Kevin
2023-02-02 7:05 ` [PATCH v1 4/8] iommufd/selftest: Add IOMMU_TEST_OP_ACCESS_SET_IOAS coverage Nicolin Chen
2023-02-02 7:05 ` [PATCH v1 5/8] iommufd: Add replace support in iommufd_access_set_ioas() Nicolin Chen
2023-02-03 10:10 ` Tian, Kevin [this message]
2023-02-03 12:31 ` Jason Gunthorpe
2023-02-03 22:25 ` Nicolin Chen
2023-02-02 7:05 ` [PATCH v1 6/8] iommufd/selftest: Add coverage for access->ioas replacement Nicolin Chen
2023-02-02 7:05 ` [PATCH v1 7/8] iommufd/device: Use iommu_group_replace_domain() Nicolin Chen
2023-02-06 8:46 ` Tian, Kevin
2023-02-06 19:17 ` Nicolin Chen
2023-02-07 0:37 ` Tian, Kevin
2023-02-02 7:05 ` [PATCH v1 8/8] vfio-iommufd: Support IO page table replacement Nicolin Chen
2023-02-06 8:49 ` Tian, Kevin
2023-02-06 18:54 ` Nicolin Chen
2023-02-03 8:09 ` [PATCH v1 0/8] Add IO page table replacement support Tian, Kevin
2023-02-03 15:04 ` Jason Gunthorpe
2023-02-06 6:39 ` Tian, Kevin
2023-02-06 13:26 ` Jason Gunthorpe
2023-02-07 0:34 ` Tian, Kevin
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