add simple xen simulation framework

To simulate booting xen just pass any parameter to main, for instance;

./main -x

Right now this fails as there is no kasan set up developed yet for Xen.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>

8 files changed, 93 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index c7dffa6..b679798 100644
--- a/Makefile
+++ b/Makefile
@@ -24,6 +24,8 @@ OBJS =  sort-init.o \
 	init.o \
 	pci.o \
 	driver.o \
+	xen.o \
+	xen-driver.o \
 	main.o
 
 main: $(OBJS)
diff --git a/init.c b/init.c
index 4ea39c4..502894c 100644
--- a/init.c
+++ b/init.c
@@ -19,8 +19,10 @@ int early_init(void)
 			printf("Initializing %s ...\n", init_fn->name);
 			ret = init_fn->early_init();
 			if (ret) {
-				if (init_fn->critical)
+				if (init_fn->critical) {
+					printf("Failed to initialize %s on early init\n", init_fn->name);
 					return ret;
+				}
 				printf("Failed to initialize %s on early init, but its not critical\n", init_fn->name);
 
 			} else
@@ -43,8 +45,10 @@ int late_init(void)
 			printf("Running late init for %s ...\n", init_fn->name);
 			ret = init_fn->late_init();
 			if (ret) {
-				if (init_fn->critical)
+				if (init_fn->critical) {
+					printf("Failed to initialize %s on late init\n", init_fn->name);
 					return ret;
+				}
 				printf("Failed to initialize %s on late init, but its not critical\n", init_fn->name);
 
 			} else
diff --git a/kasan.c b/kasan.c
index bd5765b..a07fbcd 100644
--- a/kasan.c
+++ b/kasan.c
@@ -1,10 +1,26 @@
 #include <stdio.h>
 #include <unistd.h>
+#include <errno.h>
 #include "init.h"
 
+static bool __is_kasan_setup = false;
+
+int setup_kasan_bare_metal(void) {
+	__is_kasan_setup = true;
+	return 0;
+}
+
+bool is_kasan_setup(void)
+{
+	return __is_kasan_setup;
+}
+
 static int init_kasan(void) {
 	sleep(1);
 
+	if (!is_kasan_setup())
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -16,4 +32,5 @@ struct init_fn kasan_init_fn __init_fn(INIT_EARLY) = {
 	.detect = detect_kasan,
 	.early_init = init_kasan,
 	.name = "Kasan",
+	.critical = true,
 };
diff --git a/kasan.h b/kasan.h
new file mode 100644
index 0000000..81e76de
--- /dev/null
+++ b/kasan.h
@@ -0,0 +1,4 @@
+#include <stdbool.h>
+
+int setup_kasan_bare_metal(void);
+bool is_kasan_setup(void);
diff --git a/main.c b/main.c
index bb5cafa..0e4888b 100644
--- a/main.c
+++ b/main.c
@@ -1,15 +1,31 @@
 #include <stdio.h>
+#include <stdbool.h>
 #include <unistd.h>
 #include "tables.h"
 #include "init.h"
+#include "xen.h"
+#include "kasan.h"
 
 extern struct init_fn __tbl[], __tbl_end[];
 
-int main(void)
+int bare_metal_start(void)
 {
 	int ret;
 
-	printf("Initializing world\n");
+	printf("Initializing bare metal world\n");
+	ret = setup_kasan_bare_metal();
+
+	return ret;
+}
+
+int main(int arg, char *argc[])
+{
+	int ret;
+
+	if (arg > 1)
+		xen_start();
+	else
+		bare_metal_start();
 
 	sort_table(__tbl, __tbl_end);
 	check_table_entries(__tbl, __tbl_end);
diff --git a/xen-driver.c b/xen-driver.c
new file mode 100644
index 0000000..a5f3656
--- /dev/null
+++ b/xen-driver.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <unistd.h>
+
+#include "init.h"
+#include "pci.h"
+#include "xen.h"
+
+static int early_xen_init_driver(void) {
+	sleep(2);
+
+	return 0;
+}
+
+static int detect_xen_driver(void) {
+	if (!booting_xen())
+		return 0;
+
+	return 1;
+}
+
+struct init_fn driver_xen_init_fn __init_fn(INIT_NORMAL) = {
+	.detect = detect_xen_driver,
+	.depend = detect_pci,
+	.early_init = early_xen_init_driver,
+	.name = "Xen Driver",
+};
diff --git a/xen.c b/xen.c
new file mode 100644
index 0000000..bcae856
--- /dev/null
+++ b/xen.c
@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include <stdbool.h>
+
+static bool __booting_xen = false;
+
+bool booting_xen(void)
+{
+	return __booting_xen;
+}
+
+int xen_start(void)
+{
+	__booting_xen = true;
+
+	printf("Initializing Xen guest\n");
+
+	return 0;
+}
diff --git a/xen.h b/xen.h
new file mode 100644
index 0000000..66e54e2
--- /dev/null
+++ b/xen.h
@@ -0,0 +1,2 @@
+bool booting_xen(void);
+int xen_start(void);