From 521f546b4e4cedfbfbb5787f940a592dd20dd1f2 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Thu, 10 Jun 2021 10:00:57 +0800 Subject: iommu/vt-d: Support asynchronous IOMMU nested capabilities Current VT-d implementation supports nested translation only if all underlying IOMMUs support the nested capability. This is unnecessary as the upper layer is allowed to create different containers and set them with different type of iommu backend. The IOMMU driver needs to guarantee that devices attached to a nested mode iommu_domain should support nested capabilility. Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210517065701.5078-1-baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20210610020115.1637656-6-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 65c2ed760060..b0ba187cb7f8 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4757,6 +4757,13 @@ static int prepare_domain_attach_device(struct iommu_domain *domain, if (!iommu) return -ENODEV; + if ((dmar_domain->flags & DOMAIN_FLAG_NESTING_MODE) && + !ecap_nest(iommu->ecap)) { + dev_err(dev, "%s: iommu not support nested translation\n", + iommu->name); + return -EINVAL; + } + /* 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)) @@ -5457,7 +5464,7 @@ intel_iommu_enable_nesting(struct iommu_domain *domain) int ret = -ENODEV; spin_lock_irqsave(&device_domain_lock, flags); - if (nested_mode_support() && list_empty(&dmar_domain->devices)) { + if (list_empty(&dmar_domain->devices)) { dmar_domain->flags |= DOMAIN_FLAG_NESTING_MODE; dmar_domain->flags &= ~DOMAIN_FLAG_USE_FIRST_LEVEL; ret = 0; -- cgit v1.2.3