@@ -2457,7 +2457,6 @@ 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)
@@ -2471,11 +2470,6 @@ 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
@@ -2827,9 +2821,18 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
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);
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. Notice this subtly depends on the prior arm_smmu_asid_lock change as the STE must be put to non-paging before removing the device for the linked list to avoid races with arm_smmu_share_asid(). Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)