From: Yi Liu <yi.l.liu@intel.com>
Date: Tue, 24 Oct 2023 08:00:11 -0700
Subject: iommu/vt-d: Enhance capability check for nested parent domain
allocation
Git-commit: a2cdecdf9d234455fdfc8f539bbf5818711bc29d
Patch-mainline: v6.7-rc1
References: jsc#PED-7779 jsc#PED-7780
This adds the scalable mode check before allocating the nested parent domain
as checking nested capability is not enough. User may turn off scalable mode
which also means no nested support even if the hardware supports it.
Fixes: c97d1b20d383 ("iommu/vt-d: Add domain_alloc_user op")
Link: https://lore.kernel.org/r/20231024150011.44642-1-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/intel/iommu.c | 2 +-
drivers/iommu/intel/iommu.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index fe67f8d77b09..cb64759b3d95 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4095,7 +4095,7 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags,
if (!iommu)
return ERR_PTR(-ENODEV);
- if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ecap_nest(iommu->ecap))
+ if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !nested_supported(iommu))
return ERR_PTR(-EOPNOTSUPP);
dirty_tracking = (flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING);
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 3bb569146229..cc7301579773 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -544,6 +544,8 @@ enum {
ecap_pasid((iommu)->ecap))
#define ssads_supported(iommu) (sm_supported(iommu) && \
ecap_slads((iommu)->ecap))
+#define nested_supported(iommu) (sm_supported(iommu) && \
+ ecap_nest((iommu)->ecap))
struct pasid_entry;
struct pasid_state_entry;