From: Jason Gunthorpe jgg@nvidia.com Sent: Wednesday, October 26, 2022 2:12 AM
This queries if a domain linked to a device should expect to support enforce_cache_coherency() so iommufd can negotiate the rules for when a domain should be shared or not.
For iommufd a device that declares IOMMU_CAP_ENFORCE_CACHE_COHERENCY will not be attached to a domain that does not support it.
Signed-off-by: Jason Gunthorpe jgg@nvidia.com
Reviewed-by: Kevin Tian kevin.tian@intel.com, with one nit
@@ -4458,7 +4458,11 @@ static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap) return irq_remapping_enabled == 1; if (cap == IOMMU_CAP_PRE_BOOT_PROTECTION) return dmar_platform_optin();
if (cap == IOMMU_CAP_ENFORCE_CACHE_COHERENCY) {
struct device_domain_info *info = dev_iommu_priv_get(dev);return ecap_sc_support(info->iommu->ecap);} return false;
}
use switch/case while making this change.