On 2021-07-06 07:51, Kai-Heng Feng wrote:
Commit 28b41e2c6aeb ("iommu: Move def_domain type check for untrusted
device into core") not only moved the check for untrusted device to
IOMMU core, it also introduced a behavioral change by returning
def_domain_type() directly without checking its return value. That makes
many devices no longer use the default IOMMU setting.
So revert back to the old behavior which defaults to
iommu_def_domain_type when driver callback returns 0.
Fixes: 28b41e2c6aeb ("iommu: Move def_domain type check for untrusted device into
core")
Are you sure about that? From that same commit:
@@ -1507,7 +1509,7 @@ static int iommu_alloc_default_domain(struct
iommu_group *group,
if (group->default_domain)
return 0;
- type = iommu_get_def_domain_type(dev);
+ type = iommu_get_def_domain_type(dev) ? : iommu_def_domain_type;
return iommu_group_alloc_default_domain(dev->bus, group, type);
}
AFAICS the other two callers should also handle 0 correctly. Have you
seen a problem in practice?
Robin.
Signed-off-by: Kai-Heng Feng <[email protected]>
---
drivers/iommu/iommu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5419c4b9f27a..faac4f795025 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1507,14 +1507,15 @@ EXPORT_SYMBOL_GPL(fsl_mc_device_group);
static int iommu_get_def_domain_type(struct device *dev)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
+ unsigned int type = 0;
if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted)
return IOMMU_DOMAIN_DMA;
if (ops->def_domain_type)
- return ops->def_domain_type(dev);
+ type = ops->def_domain_type(dev);
- return 0;
+ return (type == 0) ? iommu_def_domain_type : type;
}
static int iommu_group_alloc_default_domain(struct bus_type *bus,
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