linux/drivers/iommu
Jason Gunthorpe via iommu 0286300e60 iommu: iommu_group_claim_dma_owner() must always assign a domain
Once the group enters 'owned' mode it can never be assigned back to the
default_domain or to a NULL domain. It must always be actively assigned to
a current domain. If the caller hasn't provided a domain then the core
must provide an explicit DMA blocking domain that has no DMA map.

Lazily create a group-global blocking DMA domain when
iommu_group_claim_dma_owner is first called and immediately assign the
group to it. This ensures that DMA is immediately fully isolated on all
IOMMU drivers.

If the user attaches/detaches while owned then detach will set the group
back to the blocking domain.

Slightly reorganize the call chains so that
__iommu_group_set_core_domain() is the function that removes any caller
configured domain and sets the domains back a core owned domain with an
appropriate lifetime.

__iommu_group_set_domain() is the worker function that can change the
domain assigned to a group to any target domain, including NULL.

Add comments clarifying how the NULL vs detach_dev vs default_domain works
based on Robin's remarks.

This fixes an oops with VFIO and SMMUv3 because VFIO will call
iommu_detach_group() and then immediately iommu_domain_free(), but
SMMUv3 has no way to know that the domain it is holding a pointer to
has been freed. Now the iommu_detach_group() will assign the blocking
domain and SMMUv3 will no longer hold a stale domain reference.

Fixes: 1ea2a07a53 ("iommu: Add DMA ownership management interfaces")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Tested-by: Baolu Lu <baolu.lu@linux.intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
--

Just minor polishing as discussed

v3:
 - Change names to __iommu_group_set_domain() /
   __iommu_group_set_core_domain()
 - Clarify comments
 - Call __iommu_group_set_domain() directly in
   iommu_group_release_dma_owner() since we know it is always selecting
   the default_domain
 - Remove redundant detach_dev ops check in __iommu_detach_device and
   make the added WARN_ON fail instead
 - Check for blocking_domain in __iommu_attach_group() so VFIO can
   actually attach a new group
 - Update comments and spelling
 - Fix missed change to new_domain in iommu_group_do_detach_device()

v2: https://lore.kernel.org/r/0-v2-f62259511ac0+6-iommu_dma_block_jgg@nvidia.com
v1: https://lore.kernel.org/r/0-v1-6e9d2d0a759d+11b-iommu_dma_block_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/0-v3-db7f0785022b+149-iommu_dma_block_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-05-13 14:54:04 +02:00
..
amd Merge branches 'arm/mediatek', 'arm/msm', 'arm/renesas', 'arm/rockchip', 'arm/smmu', 'x86/vt-d' and 'x86/amd' into next 2022-03-08 12:21:31 +01:00
arm IOMMU Updates for Linux v5.18 2022-03-24 19:48:57 -07:00
intel IOMMU Updates for Linux v5.18 2022-03-24 19:48:57 -07:00
apple-dart.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
dma-iommu.c dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
exynos-iommu.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
fsl_pamu_domain.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
fsl_pamu_domain.h iommu/fsl_pamu: remove the snoop_id field 2021-04-07 10:56:52 +02:00
fsl_pamu.c iommu/fsl_pamu: hardcode the window address and size in pamu_config_ppaace 2021-04-07 10:56:52 +02:00
fsl_pamu.h iommu/fsl_pamu: hardcode the window address and size in pamu_config_ppaace 2021-04-07 10:56:52 +02:00
hyperv-iommu.c iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partition 2021-02-11 08:47:07 +00:00
io-pgfault.c iommu: Add a page fault handler 2021-04-07 10:54:29 +02:00
io-pgtable-arm-v7s.c iommu/io-pgtable-arm-v7s: Add error handle for page table allocation failure 2021-12-14 14:45:35 +00:00
io-pgtable-arm.c iommu/io-pgtable-arm: Fix table descriptor paddr formatting 2021-12-06 13:03:01 +01:00
io-pgtable-arm.h iommu/io-pgtable-arm: Move some definitions to a header 2020-09-28 23:48:06 +01:00
io-pgtable.c iommu/io-pgtable: Add DART pagetable format 2021-08-12 13:15:02 +02:00
ioasid.c iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit 2022-02-15 11:31:35 +01:00
iommu-debugfs.c
iommu-sva-lib.c iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit 2022-02-15 11:31:35 +01:00
iommu-sva-lib.h iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit 2022-02-15 11:31:35 +01:00
iommu-sysfs.c drivers/iommu: Export core IOMMU API symbols to permit modular drivers 2019-12-23 14:06:05 +01:00
iommu-traces.c
iommu.c iommu: iommu_group_claim_dma_owner() must always assign a domain 2022-05-13 14:54:04 +02:00
iova.c iommu/iova: Improve 32-bit free space estimate 2022-03-04 10:40:40 +01:00
ipmmu-vmsa.c Merge branches 'arm/mediatek', 'arm/msm', 'arm/renesas', 'arm/rockchip', 'arm/smmu', 'x86/vt-d' and 'x86/amd' into next 2022-03-08 12:21:31 +01:00
irq_remapping.c x86: Kill all traces of irq_remapping_get_irq_domain() 2020-10-28 20:26:28 +01:00
irq_remapping.h x86: Kill all traces of irq_remapping_get_irq_domain() 2020-10-28 20:26:28 +01:00
Kconfig iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA 2022-02-14 19:17:46 +01:00
Makefile iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA 2022-02-14 19:17:46 +01:00
msm_iommu_hw-8xxx.h
msm_iommu.c Merge branches 'arm/mediatek', 'arm/msm', 'arm/renesas', 'arm/rockchip', 'arm/smmu', 'x86/vt-d' and 'x86/amd' into next 2022-03-08 12:21:31 +01:00
msm_iommu.h
mtk_iommu_v1.c Driver core changes for 5.18-rc1 2022-03-28 12:41:28 -07:00
mtk_iommu.c Driver core changes for 5.18-rc1 2022-03-28 12:41:28 -07:00
mtk_iommu.h iommu/mediatek: Make use of the helper component_compare/release_of 2022-02-25 12:16:13 +01:00
of_iommu.c iommu: Remove unused of_get_dma_window() 2021-06-08 14:15:46 +02:00
omap-iommu-debug.c iommu/omap: Check for failure of a call to omap_iommu_dump_ctx 2020-07-22 15:02:33 +02:00
omap-iommu.c iommu/omap: Fix regression in probe for NULL pointer dereference 2022-04-08 11:16:29 +02:00
omap-iommu.h iommu/omap: add support for late attachment of iommu devices 2019-08-09 17:37:10 +02:00
omap-iopgtable.h iommu/omap: Fix -Woverflow warnings when compiling on 64-bit architectures 2020-03-04 16:24:46 +01:00
rockchip-iommu.c Merge branches 'arm/mediatek', 'arm/msm', 'arm/renesas', 'arm/rockchip', 'arm/smmu', 'x86/vt-d' and 'x86/amd' into next 2022-03-08 12:21:31 +01:00
s390-iommu.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
sprd-iommu.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
sun50i-iommu.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
tegra-gart.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00
tegra-smmu.c Merge branches 'arm/mediatek', 'arm/msm', 'arm/renesas', 'arm/rockchip', 'arm/smmu', 'x86/vt-d' and 'x86/amd' into next 2022-03-08 12:21:31 +01:00
virtio-iommu.c iommu: Split struct iommu_ops 2022-02-28 13:25:49 +01:00