1 files changed, 101 insertions, 24 deletions

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index c83bd0c2a1c9..480e7681f4f3 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -30,6 +30,7 @@
 #include <asm/io_apic.h>
 #include <asm/irq_remapping.h>
 #include <asm/set_memory.h>
+#include <asm/sev.h>
 
 #include <linux/crash_dump.h>
 
@@ -3221,6 +3222,36 @@ out:
 	return true;
 }
 
+static void iommu_snp_enable(void)
+{
+#ifdef CONFIG_KVM_AMD_SEV
+	if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP))
+		return;
+	/*
+	 * 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 disabled or configured in passthrough mode, SNP cannot be supported.\n");
+		return;
+	}
+
+	amd_iommu_snp_en = check_feature(FEATURE_SNP);
+	if (!amd_iommu_snp_en) {
+		pr_err("SNP: IOMMU SNP feature not enabled, SNP cannot be supported.\n");
+		return;
+	}
+
+	pr_info("IOMMU SNP support enabled.\n");
+
+	/* Enforce IOMMU v1 pagetable when SNP is enabled. */
+	if (amd_iommu_pgtable != AMD_IOMMU_V1) {
+		pr_warn("Forcing use of AMD IOMMU v1 page table due to SNP.\n");
+		amd_iommu_pgtable = AMD_IOMMU_V1;
+	}
+#endif
+}
+
 /****************************************************************************
  *
  * AMD IOMMU Initialization State Machine
@@ -3256,6 +3287,7 @@ static int __init state_next(void)
 		break;
 	case IOMMU_ENABLED:
 		register_syscore_ops(&amd_iommu_syscore_ops);
+		iommu_snp_enable();
 		ret = amd_iommu_init_pci();
 		init_state = ret ? IOMMU_INIT_ERROR : IOMMU_PCI_INIT;
 		break;
@@ -3767,40 +3799,85 @@ 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)
+#ifdef CONFIG_KVM_AMD_SEV
+static int iommu_page_make_shared(void *page)
 {
-	/*
-	 * 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;
+	unsigned long paddr, pfn;
+
+	paddr = iommu_virt_to_phys(page);
+	/* Cbit maybe set in the paddr */
+	pfn = __sme_clr(paddr) >> PAGE_SHIFT;
+
+	if (!(pfn % PTRS_PER_PMD)) {
+		int ret, level;
+		bool assigned;
+
+		ret = snp_lookup_rmpentry(pfn, &assigned, &level);
+		if (ret) {
+			pr_warn("IOMMU PFN %lx RMP lookup failed, ret %d\n", pfn, ret);
+			return ret;
+		}
+
+		if (!assigned) {
+			pr_warn("IOMMU PFN %lx not assigned in RMP table\n", pfn);
+			return -EINVAL;
+		}
+
+		if (level > PG_LEVEL_4K) {
+			ret = psmash(pfn);
+			if (!ret)
+				goto done;
+
+			pr_warn("PSMASH failed for IOMMU PFN %lx huge RMP entry, ret: %d, level: %d\n",
+				pfn, ret, level);
+			return ret;
+		}
 	}
 
-	/*
-	 * 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;
+done:
+	return rmp_make_shared(pfn, PG_LEVEL_4K);
+}
+
+static int iommu_make_shared(void *va, size_t size)
+{
+	void *page;
+	int ret;
+
+	if (!va)
+		return 0;
+
+	for (page = va; page < (va + size); page += PAGE_SIZE) {
+		ret = iommu_page_make_shared(page);
+		if (ret)
+			return ret;
 	}
 
-	amd_iommu_snp_en = check_feature(FEATURE_SNP);
+	return 0;
+}
+
+int amd_iommu_snp_disable(void)
+{
+	struct amd_iommu *iommu;
+	int ret;
+
 	if (!amd_iommu_snp_en)
-		return -EINVAL;
+		return 0;
+
+	for_each_iommu(iommu) {
+		ret = iommu_make_shared(iommu->evt_buf, EVT_BUFFER_SIZE);
+		if (ret)
+			return ret;
 
-	pr_info("SNP enabled\n");
+		ret = iommu_make_shared(iommu->ppr_log, PPR_LOG_SIZE);
+		if (ret)
+			return ret;
 
-	/* 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;
+		ret = iommu_make_shared((void *)iommu->cmd_sem, PAGE_SIZE);
+		if (ret)
+			return ret;
 	}
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(amd_iommu_snp_disable);
 #endif