diff options
Diffstat (limited to 'drivers/iommu/amd/init.c')
| -rw-r--r-- | drivers/iommu/amd/init.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 7c6e61451ff7..cddcb6f7e3c9 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -168,6 +168,10 @@ static int amd_iommu_target_ivhd_type; u64 amd_iommu_efr; u64 amd_iommu_efr2; +/* SNP is enabled on the system? */ +bool amd_iommu_snp_en; +EXPORT_SYMBOL(amd_iommu_snp_en); + LIST_HEAD(amd_iommu_pci_seg_list); /* list of all PCI segments */ LIST_HEAD(amd_iommu_list); /* list of all AMD IOMMUs in the system */ @@ -3556,3 +3560,41 @@ int amd_iommu_pc_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr, u8 fxn, u64 return iommu_pc_get_set_reg(iommu, bank, cntr, fxn, value, true); } + +#ifdef CONFIG_AMD_MEM_ENCRYPT +int amd_iommu_snp_enable(void) +{ + /* + * The SNP support requires that IOMMU must be enabled, and is + * not configured in the passthrough mode. + */ + if (no_iommu || iommu_default_passthrough()) { + pr_err("SNP: IOMMU is disabled or configured in passthrough mode, SNP cannot be supported"); + return -EINVAL; + } + + /* + * Prevent enabling SNP after IOMMU_ENABLED state because this process + * affect how IOMMU driver sets up data structures and configures + * IOMMU hardware. + */ + if (init_state > IOMMU_ENABLED) { + pr_err("SNP: Too late to enable SNP for IOMMU.\n"); + return -EINVAL; + } + + amd_iommu_snp_en = check_feature_on_all_iommus(FEATURE_SNP); + if (!amd_iommu_snp_en) + return -EINVAL; + + pr_info("SNP enabled\n"); + + /* Enforce IOMMU v1 pagetable when SNP is enabled. */ + if (amd_iommu_pgtable != AMD_IOMMU_V1) { + pr_warn("Force to using AMD IOMMU v1 page table due to SNP\n"); + amd_iommu_pgtable = AMD_IOMMU_V1; + } + + return 0; +} +#endif |