When setting up first level page tables for sharing with CPU, we need to ensure IOMMU can support no less than the levels supported by the CPU.
It is not adequate, as in the current code, to set up 5-level paging in PASID entry First Level Paging Mode(FLPM) solely based on CPU. Currently, intel_pasid_setup_first_level() is only used by native SVM code which already checks paging mode matches. However, future use of this helper function may not be limited to native SVM. https://lkml.org/lkml/2019/11/18/1037 Fixes: 437f35e1cd4c8 ("iommu/vt-d: Add first level page table interface") Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> Reviewed-by: Eric Auger <eric.au...@redhat.com> Acked-by: Lu Baolu <baolu...@linux.intel.com> --- drivers/iommu/intel-pasid.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c index 040a445be300..e7cb0b8a7332 100644 --- a/drivers/iommu/intel-pasid.c +++ b/drivers/iommu/intel-pasid.c @@ -499,8 +499,16 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu, } #ifdef CONFIG_X86 - if (cpu_feature_enabled(X86_FEATURE_LA57)) - pasid_set_flpm(pte, 1); + /* Both CPU and IOMMU paging mode need to match */ + if (cpu_feature_enabled(X86_FEATURE_LA57)) { + if (cap_5lp_support(iommu->cap)) { + pasid_set_flpm(pte, 1); + } else { + pr_err("VT-d has no 5-level paging support for CPU\n"); + pasid_clear_entry(pte); + return -EINVAL; + } + } #endif /* CONFIG_X86 */ pasid_set_domain_id(pte, did); -- 2.7.4 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu