[PATCH 07/12] efi: selftest: add runtime variable tests with non-volatile storage

[Harsimran Singh Tungal]

Extend runtime variable tests for persistent storage

Previously, EFI selftesting of runtime variables was only supported
under CONFIG_EFI_RT_VOLATILE_STORE, which uses VarToFile to simulate
non-volatile variable storage. This commit adds new test cases that
exercise runtime variable operations for persistent storage.

Features tested:
- Creation of runtime-accessible variables (set)
- Retrieval of runtime variables (get)
- Deletion using SetVariable() with size = 0
- Append operation using EFI_VARIABLE_APPEND_WRITE

This improves EFI compliance validation for non-volatile runtime storage
scenarios and ensures proper attribute enforcement and variable
management.

Signed-off-by: Harsimran Singh Tungal <harsimransingh.tungal at arm.com>
---
 .../efi_selftest_variables_runtime.c          | 106 +++++++++++++++++-
 1 file changed, 104 insertions(+), 2 deletions(-)

diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
index fd570d673f0..9a7ab18bc90 100644
--- a/lib/efi_selftest/efi_selftest_variables_runtime.c
+++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
@@ -3,6 +3,7 @@
  * efi_selftest_variables_runtime
  *
  * Copyright (c) 2019 Heinrich Schuchardt <xypron.glpk at gmx.de>
+ * Copyright (c) 2026 Arm Limited and/or its affiliates <open-source-office at arm.com>
  *
  * This unit test checks the runtime services for variables after
  * ExitBootServices():
@@ -22,7 +23,13 @@ static const efi_guid_t efi_rt_var_guid = U_BOOT_EFI_RT_VAR_FILE_GUID;
 /**
  * execute() - execute unit test
  *
- * As runtime support is not implmented expect EFI_UNSUPPORTED to be returned.
+ * For EFI variables in non-volatile storage, these tests have to be executed in two phases
+ * 1. During first phase, run these tests and it creates EFI variable in persistent storage.
+ * 2. Then reboot and run the test again to verify if the variable created above is still
+ *    available in non-volatile storage. If available, validate the EFI variable, append
+ *    it, and validate it again. If validation is successful, delete the same variable.
+ *
+ * Return: EFI_ST_SUCCESS on success, EFI_ST_FAILURE on failure
  */
 static int execute(void)
 {
@@ -39,6 +46,80 @@ static int execute(void)
 	u64 max_storage, rem_storage, max_size;
 	int test_ret;
 
+	/* Compare the value of EFI variable if it already exists in non volatile storage */
+	if (!IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
+		len = sizeof(v) / 2;
+		ret = st_runtime->get_variable(u"efi_st_var0", &guid_vendor0,
+				&attr, &len, data);
+		if (ret == EFI_SUCCESS) {
+			efi_st_printf("EFI Variable efi_st_var0 found. Executing Second Phase\n");
+			if (len != sizeof(v) / 2) {
+				efi_st_error("GetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+			if (memcmp(data, v, len)) {
+				efi_st_error("GetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			/* Append an existing variable */
+			append_len = sizeof(v) - len;
+			ret = st_runtime->set_variable(u"efi_st_var0", &guid_vendor0,
+						    EFI_VARIABLE_BOOTSERVICE_ACCESS |
+						    EFI_VARIABLE_RUNTIME_ACCESS |
+						    EFI_VARIABLE_APPEND_WRITE |
+						    EFI_VARIABLE_NON_VOLATILE,
+						    append_len, (v + len));
+			if (ret != EFI_SUCCESS) {
+				efi_st_error("SetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			len = sizeof(v);
+			ret = st_runtime->get_variable(u"efi_st_var0", &guid_vendor0,
+					&attr, &len, data);
+			if (ret != EFI_SUCCESS) {
+				efi_st_error("GetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			if (len != sizeof(v)) {
+				efi_st_error("GetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			if (memcmp(data, v, len)) {
+				efi_st_error("GetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			/* Delete it by setting the size to 0 */
+			ret = st_runtime->set_variable(u"efi_st_var0", &guid_vendor0,
+						    EFI_VARIABLE_BOOTSERVICE_ACCESS |
+						    EFI_VARIABLE_RUNTIME_ACCESS |
+						    EFI_VARIABLE_NON_VOLATILE,
+						    0, NULL);
+			if (ret != EFI_SUCCESS) {
+				efi_st_error("SetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			ret = st_runtime->get_variable(u"efi_st_var0", &guid_vendor0,
+					&attr, &len, data);
+			if (ret != EFI_NOT_FOUND) {
+				efi_st_error("GetVariable failed\n");
+				return EFI_ST_FAILURE;
+			}
+
+			return EFI_ST_SUCCESS;
+		} else {
+			if (ret == EFI_NOT_FOUND) {
+				efi_st_printf("EFI Variable efi_st_var0 not found. "
+					"Executing First Phase\n");
+			}
+		}
+	}
+
 	memset(v2, 0x1, sizeof(v2));
 
 	if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE)) {
@@ -279,7 +360,28 @@ static int execute(void)
 			return EFI_ST_FAILURE;
 		}
 	} else {
-		if (ret != EFI_UNSUPPORTED) {
+		if (ret != EFI_SUCCESS) {
+			efi_st_error("SetVariable failed\n");
+			return EFI_ST_FAILURE;
+		}
+
+		/* Delete it by setting the size to 0 */
+		ret = st_runtime->set_variable(u"efi_st_var0", &guid_vendor0,
+					    EFI_VARIABLE_BOOTSERVICE_ACCESS |
+					    EFI_VARIABLE_RUNTIME_ACCESS,
+					    0, NULL);
+		if (ret != EFI_SUCCESS) {
+			efi_st_error("SetVariable failed\n");
+			return EFI_ST_FAILURE;
+		}
+
+		/* Add an 8byte aligned variable */
+		ret = st_runtime->set_variable(u"efi_st_var0", &guid_vendor0,
+					    EFI_VARIABLE_BOOTSERVICE_ACCESS |
+					    EFI_VARIABLE_RUNTIME_ACCESS |
+					    EFI_VARIABLE_NON_VOLATILE,
+					    sizeof(v) / 2, v);
+		if (ret != EFI_SUCCESS) {
 			efi_st_error("SetVariable failed\n");
 			return EFI_ST_FAILURE;
 		}
-- 
2.34.1