rune/libenclave/skeleton: Support SGX1 machine without FLC

There are still lots of SGX1 machines without FLC support deployed
in filed. These machines eventually needs to be migrated to be supported
by SGX in-tree driver which is product-ready and well-maintained.

This patch targets to address the gap between SGX1 machine and SGX
in-tree driver.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>

rune/libenclave/internal/runtime/pal/skeleton/Makefile

@@ -10,11 +10,14 @@ ENCL_CFLAGS := -Wall -Werror -static -nostdlib -nostartfiles -fPIC \
 HOST_LDFLAGS := -fPIC -shared -Wl,-Bsymbolic
 
 IS_OOT_DRIVER := $(shell [ ! -e /dev/isgx ])
+IS_SGX_FLC := $(shell lscpu | grep -q sgx_lc)
 
 TEST_CUSTOM_PROGS := $(OUTPUT)/encl.bin $(OUTPUT)/encl.ss $(OUTPUT)/liberpal-skeleton.so $(OUTPUT)/signing_key.pem
 
 ifeq ($(IS_OOT_DRIVER),1)
     TEST_CUSTOM_PROGS += $(OUTPUT)/encl.token
+else ifeq ($(IS_SGX_FLC),)
+    TEST_CUSTOM_PROGS += $(OUTPUT)/encl.token
 endif
 
 all: $(TEST_CUSTOM_PROGS)

rune/libenclave/internal/runtime/pal/skeleton/liberpal-skeleton.c

@@ -31,6 +31,7 @@ static struct sgx_secs secs;
 static bool initialized = false;
 static char *sgx_dev_path;
 static bool is_oot_driver;
+static bool no_sgx_flc = false;
 /*
  * For SGX in-tree driver, dev_fd cannot be closed until an enclave instance
  * intends to exit.
@@ -221,7 +222,7 @@ static bool encl_build(struct sgx_secs *secs, void *bin, unsigned long bin_size,
 			goto out_map;
 	}
 
-	if (is_oot_driver) {
+	if (is_oot_driver || no_sgx_flc) {
 		struct sgx_enclave_init_with_token ioc;
 		ioc.addr = secs->base;
 		ioc.sigstruct = (uint64_t)sigstruct;
@@ -359,6 +360,37 @@ static bool load_token(const char *path, void *token)
 	return true;
 }
 
+static void check_opts(const char *opt)
+{
+	if (!strcmp(opt, "no-sgx-flc"))
+		no_sgx_flc = true;
+}
+
+static void parse_args(const char *args)
+{
+	char *a = strdup(args);
+	if (!a)
+		return;
+
+	char *opt = strtok(a, " ");
+	check_opts(opt);
+
+	if (!opt) {
+		free(a);
+		return;
+	}
+
+	do {
+		char *opt = strtok(NULL, " ");
+		if (!opt)
+			break;
+
+		check_opts(opt);
+	} while (1);
+
+	free(a);
+}
+
 int pal_get_version(void)
 {
 	return 1;
@@ -376,6 +408,8 @@ int pal_init(pal_attr_t *attr)
 	off_t bin_size;
 	void *bin;
 
+	parse_args(attr->args);
+
 	detect_driver_type();
 
 	if (!encl_data_map(IMAGE, &bin, &bin_size))