In the attach_dev callback of the default domain ops, if the domain has
been set force_snooping, but the iommu hardware of the device does not
support SC(Snoop Control) capability, the callback should block it and
return a corresponding error code.
Signed-off-by: Lu Baolu
---
drivers/iommu/intel/iommu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cf43e8f9091b..d68f5bbf3e93 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4354,6 +4354,9 @@ static int prepare_domain_attach_device(struct
iommu_domain *domain,
if (!iommu)
return -ENODEV;
+ if (dmar_domain->force_snooping && !ecap_sc_support(iommu->ecap))
+ return -EOPNOTSUPP;
+
/* check if this iommu agaw is sufficient for max mapped address */
addr_width = agaw_to_width(iommu->agaw);
if (addr_width > cap_mgaw(iommu->cap))
--
2.25.1
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