kvm tools: add init/exit automatic calls

This adds a method to call init/exit functions similar to the kernel's init functions.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/include/kvm/util-init.h b/tools/kvm/include/kvm/util-init.h
new file mode 100644 (file)
index 0000000..13d4f04
--- /dev/null
+++ b/tools/kvm/include/kvm/util-init.h
@@ -0,0 +1,51 @@
+#ifndef KVM__UTIL_INIT_H
+#define KVM__UTIL_INIT_H
+
+struct kvm;
+
+struct init_item {
+       struct hlist_node n;
+       const char *fn_name;
+       int (*init)(struct kvm *);
+};
+
+int init_list__init(struct kvm *kvm);
+int init_list__exit(struct kvm *kvm);
+
+int init_list_add(struct init_item *t, int (*init)(struct kvm *),
+                       int priority, const char *name);
+int exit_list_add(struct init_item *t, int (*init)(struct kvm *),
+                       int priority, const char *name);
+
+#define __init_list_add(cb, l)                                         \
+static void __attribute__ ((constructor)) __init__##cb(void)           \
+{                                                                      \
+       static char name[] = #cb;                                       \
+       static struct init_item t;                                      \
+       init_list_add(&t, cb, l, name);                                 \
+}
+
+#define __exit_list_add(cb, l)                                         \
+static void __attribute__ ((constructor)) __init__##cb(void)           \
+{                                                                      \
+       static char name[] = #cb;                                       \
+       static struct init_item t;                                      \
+       exit_list_add(&t, cb, l, name);                                 \
+}
+
+#define core_init(cb) __init_list_add(cb, 0)
+#define base_init(cb) __init_list_add(cb, 2)
+#define dev_base_init(cb)  __init_list_add(cb, 4)
+#define dev_init(cb) __init_list_add(cb, 5)
+#define virtio_dev_init(cb) __init_list_add(cb, 6)
+#define firmware_init(cb) __init_list_add(cb, 7)
+#define late_init(cb) __init_list_add(cb, 9)
+
+#define core_exit(cb) __exit_list_add(cb, 0)
+#define base_exit(cb) __exit_list_add(cb, 2)
+#define dev_base_exit(cb) __exit_list_add(cb, 4)
+#define dev_exit(cb) __exit_list_add(cb, 5)
+#define virtio_dev_exit(cb) __exit_list_add(cb, 6)
+#define firmware_exit(cb) __exit_list_add(cb, 7)
+#define late_exit(cb) __exit_list_add(cb, 9)
+#endif

diff --git a/tools/kvm/util/init.c b/tools/kvm/util/init.c
new file mode 100644 (file)
index 0000000..33a5952
--- /dev/null
+++ b/tools/kvm/util/init.c
@@ -0,0 +1,69 @@
+#include <linux/list.h>
+#include <linux/kernel.h>
+
+#include "kvm/kvm.h"
+#include "kvm/util-init.h"
+
+#define PRIORITY_LISTS 10
+
+static struct hlist_head init_lists[PRIORITY_LISTS];
+static struct hlist_head exit_lists[PRIORITY_LISTS];
+
+int init_list_add(struct init_item *t, int (*init)(struct kvm *),
+                       int priority, const char *name)
+{
+       t->init = init;
+       t->fn_name = name;
+       hlist_add_head(&t->n, &init_lists[priority]);
+
+       return 0;
+}
+
+int exit_list_add(struct init_item *t, int (*init)(struct kvm *),
+                       int priority, const char *name)
+{
+       t->init = init;
+       t->fn_name = name;
+       hlist_add_head(&t->n, &exit_lists[priority]);
+
+       return 0;
+}
+
+int init_list__init(struct kvm *kvm)
+{
+       unsigned int i;
+       int r = 0;
+       struct hlist_node *n;
+       struct init_item *t;
+
+       for (i = 0; i < ARRAY_SIZE(init_lists); i++)
+               hlist_for_each_entry(t, n, &init_lists[i], n) {
+                       r = t->init(kvm);
+                       if (r < 0) {
+                               pr_warning("Failed init: %s\n", t->fn_name);
+                               goto fail;
+                       }
+               }
+
+fail:
+       return r;
+}
+
+int init_list__exit(struct kvm *kvm)
+{
+       int i;
+       int r = 0;
+       struct hlist_node *n;
+       struct init_item *t;
+
+       for (i = ARRAY_SIZE(exit_lists) - 1; i >= 0; i--)
+               hlist_for_each_entry(t, n, &exit_lists[i], n) {
+                       r = t->init(kvm);
+                       if (r < 0) {
+                               pr_warning("%s failed.\n", t->fn_name);
+                               goto fail;
+                       }
+               }
+fail:
+       return r;
+}