diff options
| -rw-r--r-- | drivers/iommu/amd/amd_iommu.h | 2 | ||||
| -rw-r--r-- | drivers/iommu/amd/init.c | 42 | ||||
| -rw-r--r-- | include/linux/amd-iommu.h | 4 |
3 files changed, 48 insertions, 0 deletions
diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h index 1b945d47741c..84e5bb1bf01b 100644 --- a/drivers/iommu/amd/amd_iommu.h +++ b/drivers/iommu/amd/amd_iommu.h @@ -140,4 +140,6 @@ extern struct dev_table_entry *get_dev_table(struct amd_iommu *iommu); extern u64 amd_iommu_efr; extern u64 amd_iommu_efr2; + +extern bool amd_iommu_snp_en; #endif 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 diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h index 58e6c3806c09..953e6f12fa1c 100644 --- a/include/linux/amd-iommu.h +++ b/include/linux/amd-iommu.h @@ -206,4 +206,8 @@ int amd_iommu_pc_get_reg(struct amd_iommu *iommu, u8 bank, u8 cntr, u8 fxn, u64 *value); struct amd_iommu *get_amd_iommu(unsigned int idx); +#ifdef CONFIG_AMD_MEM_ENCRYPT +int amd_iommu_snp_enable(void); +#endif + #endif /* _ASM_X86_AMD_IOMMU_H */ |