kvm tools: Embed init and init_stage2 into lkvm binary

We generate guest init and init_stage2 on the fly and put them in

   ~/.lkvm/$guest/virt/init
   ~/.lkvm/$guest/virt/init_stage2
.

This makes 'lkvm run' no longer depending on guest/{int, init_stage2}.

Further, we can merge init and init_stage2 since there is no need to
split the init function into two stages any more.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
index 2bf931bbfa3e2b0289eb5d9f877d83a7c6d9e44a..1099b76d772a7f4f0a2c1717763ad71877ecb6fe 100644 (file)
--- a/tools/kvm/Makefile
+++ b/tools/kvm/Makefile
@@ -286,14 +286,15 @@ KVMTOOLS-VERSION-FILE:
 # $(OTHEROBJS) are things that do not get substituted like this.
 #
 STATIC_OBJS = $(patsubst %.o,%.static.o,$(OBJS) $(OBJS_STATOPT))
+GUEST_OBJS = guest/guest_init.o guest/guest_init_stage2.o
 
-$(PROGRAM)-static:  $(DEPS) $(STATIC_OBJS) $(OTHEROBJS)
+$(PROGRAM)-static:  $(DEPS) $(STATIC_OBJS) $(OTHEROBJS) $(GUEST_INIT) $(GUEST_INIT_S2)
        $(E) "  LINK    " $@
-       $(Q) $(CC) -static $(CFLAGS) $(STATIC_OBJS) $(OTHEROBJS) $(LIBS) $(LIBS_STATOPT) -o $@
+       $(Q) $(CC) -static $(CFLAGS) $(STATIC_OBJS) $(OTHEROBJS) $(GUEST_OBJS) $(LIBS) $(LIBS_STATOPT) -o $@
 
-$(PROGRAM): $(DEPS) $(OBJS) $(OBJS_DYNOPT) $(OTHEROBJS)
+$(PROGRAM): $(DEPS) $(OBJS) $(OBJS_DYNOPT) $(OTHEROBJS) $(GUEST_INIT) $(GUEST_INIT_S2)
        $(E) "  LINK    " $@
-       $(Q) $(CC) $(CFLAGS) $(OBJS) $(OBJS_DYNOPT) $(OTHEROBJS) $(LIBS) $(LIBS_DYNOPT) -o $@
+       $(Q) $(CC) $(CFLAGS) $(OBJS) $(OBJS_DYNOPT) $(OTHEROBJS) $(GUEST_OBJS) $(LIBS) $(LIBS_DYNOPT) -o $@
 
 $(PROGRAM_ALIAS): $(PROGRAM)
        $(E) "  LN      " $@
@@ -302,10 +303,12 @@ $(PROGRAM_ALIAS): $(PROGRAM)
 $(GUEST_INIT): guest/init.c
        $(E) "  LINK    " $@
        $(Q) $(CC) -static guest/init.c -o $@
+       $(Q) ld -r -b binary -o guest/guest_init.o $(GUEST_INIT)
 
 $(GUEST_INIT_S2): guest/init_stage2.c
        $(E) "  LINK    " $@
        $(Q) $(CC) -static guest/init_stage2.c -o $@
+       $(Q) ld -r -b binary -o guest/guest_init_stage2.o $(GUEST_INIT_S2)
 
 $(DEPS):
 
@@ -403,7 +406,7 @@ clean:
        $(Q) rm -f x86/bios/bios-rom.h
        $(Q) rm -f tests/boot/boot_test.iso
        $(Q) rm -rf tests/boot/rootfs/
-       $(Q) rm -f $(DEPS) $(OBJS) $(OTHEROBJS) $(OBJS_DYNOPT) $(STATIC_OBJS) $(PROGRAM) $(PROGRAM_ALIAS) $(PROGRAM)-static $(GUEST_INIT) $(GUEST_INIT_S2)
+       $(Q) rm -f $(DEPS) $(OBJS) $(OTHEROBJS) $(OBJS_DYNOPT) $(STATIC_OBJS) $(PROGRAM) $(PROGRAM_ALIAS) $(PROGRAM)-static $(GUEST_INIT) $(GUEST_INIT_S2) $(GUEST_OBJS)
        $(Q) rm -f cscope.*
        $(Q) rm -f tags
        $(Q) rm -f TAGS

diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c
index befce9eaab4a7119dc88ee763e09f33b3bb78f36..1b407a65d867b8316f85aaadd5df3d404350258c 100644 (file)
--- a/tools/kvm/builtin-run.c
+++ b/tools/kvm/builtin-run.c
@@ -111,6 +111,11 @@ bool do_debug_print = false;
 static int nrcpus;
 static int vidmode = -1;
 
+extern char _binary_guest_init_stage2_start;
+extern char _binary_guest_init_stage2_size;
+extern char _binary_guest_init_start;
+extern char _binary_guest_init_size;
+
 static const char * const run_usage[] = {
        "lkvm run [<options>] [<kernel image>]",
        NULL
@@ -803,24 +808,41 @@ void kvm_run_help(void)
        usage_with_options(run_usage, options);
 }
 
-static int kvm_custom_stage2(void)
+static int kvm_setup_guest_init(void)
 {
-       char tmp[PATH_MAX], dst[PATH_MAX], *src;
        const char *rootfs = custom_rootfs_name;
-       int r;
-
-       src = realpath("guest/init_stage2", NULL);
-       if (src == NULL)
-               return -ENOMEM;
+       char tmp[PATH_MAX];
+       size_t size;
+       int fd, ret;
+       char *data;
+
+       /* Setup /virt/init */
+       size = (size_t)&_binary_guest_init_size;
+       data = (char *)&_binary_guest_init_start;
+       snprintf(tmp, PATH_MAX, "%s%s/virt/init", kvm__get_dir(), rootfs);
+       remove(tmp);
+       fd = open(tmp, O_CREAT | O_WRONLY, 0755);
+       if (fd < 0)
+               die("Fail to setup %s", tmp);
+       ret = xwrite(fd, data, size);
+       if (ret < 0)
+               die("Fail to setup %s", tmp);
+       close(fd);
 
+       /* Setup /virt/init_stage2 */
+       size = (size_t)&_binary_guest_init_stage2_size;
+       data = (char *)&_binary_guest_init_stage2_start;
        snprintf(tmp, PATH_MAX, "%s%s/virt/init_stage2", kvm__get_dir(), rootfs);
        remove(tmp);
+       fd = open(tmp, O_CREAT | O_WRONLY, 0755);
+       if (fd < 0)
+               die("Fail to setup %s", tmp);
+       ret = xwrite(fd, data, size);
+       if (ret < 0)
+               die("Fail to setup %s", tmp);
+       close(fd);
 
-       snprintf(dst, PATH_MAX, "/host/%s", src);
-       r = symlink(dst, tmp);
-       free(src);
-
-       return r;
+       return 0;
 }
 
 static int kvm_run_set_sandbox(void)
@@ -1147,8 +1169,8 @@ static int kvm_cmd_run_init(int argc, const char **argv)
 
                        if (!no_dhcp)
                                strcat(real_cmdline, "  ip=dhcp");
-                       if (kvm_custom_stage2())
-                               die("Failed linking stage 2 of init.");
+                       if (kvm_setup_guest_init())
+                               die("Failed to setup init for guest.");
                }
        } else if (!strstr(real_cmdline, "root=")) {
                strlcat(real_cmdline, " root=/dev/vda rw ", sizeof(real_cmdline));