[kvm-unit-tests PATCH v1 3/3] x86 UEFI: read args from file

[Zixuan Wang <zxwang42@xxxxxxxxx>]

From: Zixuan Wang <zxwang42@xxxxxxxxx>

This commit enables kvm-unit-tests to get args from the host through
UEFI.

Previously, when compiled to run under UEFI, kvm-unit-tests could not
get args from the host through QEMU's '-append' argument. This is
because kvm-unit-tests (under UEFI) does not rely on QEMU's '-kernel'
argument, while without which, QEMU rejects the '-append' argument.

This commit enables the host to pass the args through a file. This
process is similar to the '-initrd' support introduced in the previous
commit.

Signed-off-by: Zixuan Wang <zxwang42@xxxxxxxxx>
---
 lib/efi.c   | 24 ++++++++++++++++++++++++
 x86/efi/run | 12 +++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/lib/efi.c b/lib/efi.c
index 4ddc3a4..dfde788 100644
--- a/lib/efi.c
+++ b/lib/efi.c
@@ -14,6 +14,7 @@
 
 /* From lib/argv.c */
 extern int __argc, __envc;
+extern const char *__args;
 extern char *__argv[100];
 extern char *__environ[200];
 
@@ -212,6 +213,28 @@ efi_set_up_envs_error:
 	return EFI_ABORTED;
 }
 
+static efi_status_t efi_set_up_args(efi_file_protocol_t *volume)
+{
+	efi_char16_t file_name[] = L"ARGS.TXT";
+	unsigned long file_size;
+	char *file_data = NULL;
+	efi_status_t status;
+
+	status = efi_read_file(volume, file_name, &file_size, &file_data);
+	if (status != EFI_SUCCESS) {
+		printf("Failed to read file\n");
+		goto efi_set_up_envs_error;
+	}
+
+	__args = file_data;
+	__setup_args();
+
+	return EFI_SUCCESS;
+
+efi_set_up_envs_error:
+	return EFI_ABORTED;
+}
+
 efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
 {
 	int ret;
@@ -234,6 +257,7 @@ efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
 	}
 
 	efi_set_up_envs(volume);
+	efi_set_up_args(volume);
 
 	/* Set up efi_bootinfo */
 	efi_bootinfo.mem_map.map = &map;
diff --git a/x86/efi/run b/x86/efi/run
index f4a5930..e02a6e1 100755
--- a/x86/efi/run
+++ b/x86/efi/run
@@ -44,9 +44,10 @@ fi
 mkdir -p "$EFI_CASE_DIR"
 cp "$EFI_SRC/$EFI_CASE.efi" "$EFI_CASE_BINARY"
 
-# Capture -initrd
+# Capture -initrd and -append
 efi_qemu_args=""
 efi_qemu_initrd=""
+efi_qemu_append=""
 while [[ -n "$1" ]]; do
 	case "$1" in
 		--initrd|-initrd)
@@ -54,6 +55,11 @@ while [[ -n "$1" ]]; do
 			efi_qemu_initrd="$1"
 			shift 1
 		;;
+		--append|-append)
+			shift 1
+			efi_qemu_append="$1"
+			shift 1
+		;;
 		*)
 			efi_qemu_args+=" $1"
 			shift 1
@@ -67,6 +73,10 @@ KVM_UNIT_TESTS_EFI_ENV="$EFI_TEST/$EFI_CASE/ENVS.TXT"
 mv "$KVM_UNIT_TESTS_ENV" "$KVM_UNIT_TESTS_EFI_ENV"
 [[ -f "$efi_qemu_initrd" ]] && cat "$efi_qemu_initrd" >> "$KVM_UNIT_TESTS_EFI_ENV"
 
+# Create ARGS file
+KVM_UNIT_TESTS_EFI_ARG="$EFI_TEST/$EFI_CASE/ARGS.TXT"
+echo -n "$efi_qemu_append" > "$KVM_UNIT_TESTS_EFI_ARG"
+
 # Run test case with 256MiB QEMU memory. QEMU default memory size is 128MiB.
 # After UEFI boot up and we call `LibMemoryMap()`, the largest consecutive
 # memory region is ~42MiB. Although this is sufficient for many test cases to
-- 
2.35.1