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 <baolu...@linux.intel.com> Reviewed-by: Jason Gunthorpe <j...@nvidia.com> Reviewed-by: Kevin Tian <kevin.t...@intel.com> --- 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 2990f80c5e08..b4802f4055a0 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4367,6 +4367,9 @@ 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 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu