diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2024-02-26 13:07:18 -0400 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2024-02-29 15:12:22 +0000 |
| commit | 8c73c32c83ce7f3c31864cb044abd3daefacd996 (patch) | |
| tree | 10295b74fb4b22a1fc66e3756c269fe327386f50 /drivers/iommu | |
| parent | 65547275d76965c3106fbcd4a9244242eb88224c (diff) | |
iommu/arm-smmu-v3: Do not change the STE twice during arm_smmu_attach_dev()
This was needed because the STE code required the STE to be in
ABORT/BYPASS inorder to program a cdtable or S2 STE. Now that the STE code
can automatically handle all transitions we can remove this step
from the attach_dev flow.
A few small bugs exist because of this:
1) If the core code does BLOCKED -> UNMANAGED with disable_bypass=false
then there will be a moment where the STE points at BYPASS. Since
this can be done by VFIO/IOMMUFD it is a small security race.
2) If the core code does IDENTITY -> DMA then any IOMMU_RESV_DIRECT
regions will temporarily become BLOCKED. We'd like drivers to
work in a way that allows IOMMU_RESV_DIRECT to be continuously
functional during these transitions.
Make arm_smmu_release_device() put the STE back to the correct
ABORT/BYPASS setting. Fix a bug where a IOMMU_RESV_DIRECT was ignored on
this path.
As noted before the reordering of the linked list/STE/CD changes is OK
against concurrent arm_smmu_share_asid() because of the
arm_smmu_asid_lock.
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Moritz Fischer <moritzf@google.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/7-v6-96275f25c39d+2d4-smmuv3_newapi_p1_jgg@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 6cdf075e9a7e..597a8c5f9658 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2509,7 +2509,6 @@ static void arm_smmu_disable_pasid(struct arm_smmu_master *master) static void arm_smmu_detach_dev(struct arm_smmu_master *master) { unsigned long flags; - struct arm_smmu_ste target; struct arm_smmu_domain *smmu_domain = master->domain; if (!smmu_domain) @@ -2523,11 +2522,6 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master) master->domain = NULL; master->ats_enabled = false; - if (disable_bypass) - arm_smmu_make_abort_ste(&target); - else - arm_smmu_make_bypass_ste(&target); - arm_smmu_install_ste_for_dev(master, &target); /* * Clearing the CD entry isn't strictly required to detach the domain * since the table is uninstalled anyway, but it helps avoid confusion @@ -2875,9 +2869,18 @@ err_free_master: static void arm_smmu_release_device(struct device *dev) { struct arm_smmu_master *master = dev_iommu_priv_get(dev); + struct arm_smmu_ste target; if (WARN_ON(arm_smmu_master_sva_enabled(master))) iopf_queue_remove_device(master->smmu->evtq.iopf, dev); + + /* Put the STE back to what arm_smmu_init_strtab() sets */ + if (disable_bypass && !dev->iommu->require_direct) + arm_smmu_make_abort_ste(&target); + else + arm_smmu_make_bypass_ste(&target); + arm_smmu_install_ste_for_dev(master, &target); + arm_smmu_detach_dev(master); arm_smmu_disable_pasid(master); arm_smmu_remove_master(master); |