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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 5/5] libxl: domain save/restore: run in a separate process
libxenctrl expects to be able to simply run the save or restore
operation synchronously. This won't work well in a process which is
trying to handle multiple domains.
The options are:
- Block such a whole process (eg, the whole of libvirt) while
migration completes (or until it fails).
- Create a thread to run xc_domain_save and xc_domain_restore on.
This is quite unpalatable. Multithreaded programming is error
prone enough without generating threads in libraries, particularly
if the thread does some very complex operation.
- Fork and run the operation in the child without execing. This is
no good because we would need to negotiate with the caller about
fds we would inherit (and we might be a very large process).
- Fork and exec a helper.
Of these options the latter is the most palatable.
Consequently:
* A new helper program libxl-save-helper (which does both save and
restore). It will be installed in /usr/lib/xen/bin. It does not
link against libxl, only libxc, and its error handling does not
need to be very advanced. It does contain a plumbing through of
the logging interface into the callback stream.
* A small ad-hoc protocol between the helper and libxl which allows
log messages and the libxc callbacks to be passed up and down.
Protocol doc comment is in libxl_save_helper.c.
* To avoid a lot of tedium the marshalling boilerplate (stubs for the
helper and the callback decoder for libxl) is generated with a
small perl script.
* The callback functions in libxl are renamed to the systematic
naming scheme from the marshalling boilerplate. This hardwires the
libxl callbacks.
* Implement new functionality to spawn the helper, monitor its
output, provide responses, and check on its exit status.
* The functions libxl__xc_domain_restore_done and
libxl__xc_domain_save_done now turn out to want be called in the
same place. So make their state argument a void* so that the two
functions are type compatible.
The domain save path still writes the qemu savefile synchronously.
This will need to be fixed in a subsequent patch.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
.gitignore | 1 +
.hgignore | 2 +
tools/libxl/Makefile | 19 ++-
tools/libxl/libxl_create.c | 24 ++-
tools/libxl/libxl_dom.c | 34 +++--
tools/libxl/libxl_internal.h | 47 ++++--
tools/libxl/libxl_save_callout.c | 318 +++++++++++++++++++++++++++++++++---
tools/libxl/libxl_save_helper.c | 273 +++++++++++++++++++++++++++++++
tools/libxl/libxl_save_msgs_gen.pl | 305 ++++++++++++++++++++++++++++++++++
9 files changed, 965 insertions(+), 58 deletions(-)
create mode 100644 tools/libxl/libxl_save_helper.c
create mode 100755 tools/libxl/libxl_save_msgs_gen.pl
diff --git a/.gitignore b/.gitignore
index 7770e54..3451e52 100644
--- a/.gitignore
+++ b/.gitignore
@@ -353,6 +353,7 @@ tools/libxl/_*.[ch]
tools/libxl/testidl
tools/libxl/testidl.c
tools/libxl/*.pyc
+tools/libxl/libxl-save-helper
tools/blktap2/control/tap-ctl
tools/firmware/etherboot/eb-roms.h
tools/firmware/etherboot/gpxe-git-snapshot.tar.gz
diff --git a/.hgignore b/.hgignore
index 27d8f79..05304ea 100644
--- a/.hgignore
+++ b/.hgignore
@@ -180,9 +180,11 @@
^tools/libxl/_.*\.c$
^tools/libxl/libxlu_cfg_y\.output$
^tools/libxl/xl$
+^tools/libxl/libxl-save-helper$
^tools/libxl/testidl$
^tools/libxl/testidl\.c$
^tools/libxl/tmp\..*$
+^tools/libxl/.*\.new$
^tools/libvchan/vchan-node[12]$
^tools/libaio/src/.*\.ol$
^tools/libaio/src/.*\.os$
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 9b84421..09f5e9d 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -66,25 +66,29 @@ LIBXL_OBJS = flexarray.o libxl.o libxl_create.o libxl_dm.o
libxl_pci.o \
libxl_dom.o libxl_exec.o libxl_xshelp.o libxl_device.o \
libxl_internal.o libxl_utils.o libxl_uuid.o \
libxl_json.o libxl_aoutils.o \
- libxl_save_callout.o \
+ libxl_save_callout.o _libxl_save_msgs_callout.o \
libxl_qmp.o libxl_event.o libxl_fork.o $(LIBXL_OBJS-y)
LIBXL_OBJS += _libxl_types.o libxl_flask.o _libxl_types_internal.o
$(LIBXL_OBJS): CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenguest)
$(CFLAGS_libxenstore) $(CFLAGS_libblktapctl) -include $(XEN_ROOT)/tools/config.h
-AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h _libxl_list.h
+AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h _libxl_save_msgs.h _libxl_list.h
AUTOSRCS= libxlu_cfg_y.c libxlu_cfg_l.c
+AUTOSRCS += _libxl_save_msgs_callout.c _libxl_save_msgs_helper.c
LIBXLU_OBJS = libxlu_cfg_y.o libxlu_cfg_l.o libxlu_cfg.o \
libxlu_disk_l.o libxlu_disk.o libxlu_vif.o libxlu_pci.o
$(LIBXLU_OBJS): CFLAGS += $(CFLAGS_libxenctrl) # For xentoollog.h
-CLIENTS = xl testidl
+CLIENTS = xl testidl libxl-save-helper
XL_OBJS = xl.o xl_cmdimpl.o xl_cmdtable.o xl_sxp.o
$(XL_OBJS): CFLAGS += $(CFLAGS_libxenctrl) # For xentoollog.h
$(XL_OBJS): CFLAGS += $(CFLAGS_libxenlight)
$(XL_OBJS): CFLAGS += -include $(XEN_ROOT)/tools/config.h # libxl_json.h needs
it.
+SAVE_HELPER_OBJS = libxl_save_helper.o _libxl_save_msgs_helper.o
+$(SAVE_HELPER_OBJS): CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenlight)
+
testidl.o: CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenlight)
testidl.c: libxl_types.idl gentest.py libxl.h $(AUTOINCS)
$(PYTHON) gentest.py libxl_types.idl testidl.c.new
@@ -116,6 +120,11 @@ _libxl_list.h:
$(XEN_INCLUDE)/xen-external/bsd-sys-queue-h-seddery $(XEN_INCLUDE
perl $^ --prefix=libxl >$@.new
$(call move-if-changed,$@.new,$@)
+_libxl_save_msgs.h _libxl_save_msgs_helper.c _libxl_save_msgs_callout.c: \
+ libxl_save_msgs_gen.pl
+ $(PERL) -w $< $@ >$@.new
+ $(call move-if-changed,$@.new,$@)
+
libxl.h: _libxl_types.h
libxl_json.h: _libxl_types_json.h
libxl_internal.h: _libxl_types_internal.h _libxl_paths.h
@@ -157,6 +166,9 @@ libxlutil.a: $(LIBXLU_OBJS)
xl: $(XL_OBJS) libxlutil.so libxenlight.so
$(CC) $(LDFLAGS) -o $@ $(XL_OBJS) libxlutil.so $(LDLIBS_libxenlight)
$(LDLIBS_libxenctrl) -lyajl $(APPEND_LDFLAGS)
+libxl-save-helper: $(SAVE_HELPER_OBJS) libxenlight.so
+ $(CC) $(LDFLAGS) -o $@ $(SAVE_HELPER_OBJS) $(LDLIBS_libxenctrl)
$(LDLIBS_libxenguest) $(APPEND_LDFLAGS)
+
testidl: testidl.o libxlutil.so libxenlight.so
$(CC) $(LDFLAGS) -o $@ testidl.o libxlutil.so $(LDLIBS_libxenlight)
$(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
@@ -168,6 +180,7 @@ install: all
$(INSTALL_DIR) $(DESTDIR)$(BASH_COMPLETION_DIR)
$(INSTALL_DIR) $(DESTDIR)$(XEN_RUN_DIR)
$(INSTALL_PROG) xl $(DESTDIR)$(SBINDIR)
+ $(INSTALL_PROG) libxl-save-helper $(DESTDIR)$(PRIVATE_BINDIR)
$(INSTALL_PROG) libxenlight.so.$(MAJOR).$(MINOR) $(DESTDIR)$(LIBDIR)
ln -sf libxenlight.so.$(MAJOR).$(MINOR)
$(DESTDIR)$(LIBDIR)/libxenlight.so.$(MAJOR)
ln -sf libxenlight.so.$(MAJOR) $(DESTDIR)$(LIBDIR)/libxenlight.so
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 7f42737..952c0aa 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -617,14 +617,12 @@ static void domcreate_bootloader_done(libxl__egc *egc,
/* read signature */
int hvm, pae, superpages;
int no_incr_generationid;
- xc_toolstack_restore_cb *toolstack_restore = NULL;
switch (info->type) {
case LIBXL_DOMAIN_TYPE_HVM:
hvm = 1;
superpages = 1;
pae = libxl_defbool_val(info->u.hvm.pae);
no_incr_generationid =
!libxl_defbool_val(info->u.hvm.incr_generationid);
- toolstack_restore = libxl__toolstack_restore;
break;
case LIBXL_DOMAIN_TYPE_PV:
hvm = 0;
@@ -637,18 +635,32 @@ static void domcreate_bootloader_done(libxl__egc *egc,
goto out;
}
libxl__xc_domain_restore(egc, dcs,
- hvm, pae, superpages, no_incr_generationid,
- toolstack_restore);
+ hvm, pae, superpages, no_incr_generationid);
return;
out:
libxl__xc_domain_restore_done(egc, dcs, rc, 0, 0);
}
-void libxl__xc_domain_restore_done(libxl__egc *egc,
- libxl__domain_create_state *dcs,
+void libxl_srm_callout_callback_restore_results(unsigned long store_mfn,
+ unsigned long console_mfn, unsigned long genidad, void *user_void)
+{
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__domain_create_state *dcs = user->caller_state;
+ libxl__save_helper_state *shs = user->shs;
+ STATE_AO_GC(dcs->ao);
+ libxl__domain_build_state *const state = &dcs->build_state;
+
+ state->store_mfn = store_mfn;
+ state->console_mfn = console_mfn;
+ state->vm_generationid_addr = genidad;
+ shs->need_results = 0;
+}
+
+void libxl__xc_domain_restore_done(libxl__egc *egc, void *dcs_void,
int ret, int retval, int errnoval)
{
+ libxl__domain_create_state *dcs = dcs_void;
STATE_AO_GC(dcs->ao);
libxl_ctx *ctx = libxl__gc_owner(gc);
char **vments = NULL, **localents = NULL;
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index d28f740..464078d 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -458,11 +458,14 @@ static inline char *restore_helper(libxl__gc *gc,
uint32_t domid,
domid, phys_offset, node);
}
-int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
- uint32_t size, void *data)
+int libxl_srm_callout_callback_toolstack_restore(uint32_t domid,
+ const uint8_t *buf, uint32_t size,
+ void *user_void)
{
- libxl__gc *gc = data;
- libxl_ctx *ctx = gc->owner;
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__domain_create_state *dcs = user->caller_state;
+ STATE_AO_GC(dcs->ao);
+ libxl_ctx *ctx = CTX;
int i, ret;
const uint8_t *ptr = buf;
uint32_t count = 0, version = 0;
@@ -522,10 +525,14 @@ static void domain_suspend_done(libxl__egc *egc,
/*----- callbacks, called by xc_domain_save -----*/
-int libxl__domain_suspend_common_switch_qemu_logdirty
- (int domid, unsigned int enable, void *data)
+int libxl_srm_callout_callback_postcopy(void *user) { return 0; }
+int libxl_srm_callout_callback_checkpoint(void *user) { return 0; }
+
+int libxl_srm_callout_callback_switch_qemu_logdirty(int domid, unsigned enable,
+ void *user_void)
{
- libxl__domain_suspend_state *dss = data;
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__domain_suspend_state *dss = user->caller_state;
STATE_AO_GC(dss->ao);
char *path;
bool rc;
@@ -543,9 +550,10 @@ int libxl__domain_suspend_common_switch_qemu_logdirty
return rc ? 0 : 1;
}
-int libxl__domain_suspend_common_callback(void *data)
+int libxl_srm_callout_callback_suspend(void *user_void)
{
- libxl__domain_suspend_state *dss = data;
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__domain_suspend_state *dss = user->caller_state;
STATE_AO_GC(dss->ao);
unsigned long hvm_s_state = 0, hvm_pvdrv = 0;
int ret;
@@ -675,9 +683,9 @@ static inline char *save_helper(libxl__gc *gc, uint32_t
domid,
}
int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
- uint32_t *len, void *data)
+ uint32_t *len, void *dss_void)
{
- libxl__domain_suspend_state *dss = data;
+ libxl__domain_suspend_state *dss = dss_void;
STATE_AO_GC(dss->ao);
int i = 0;
char *start_addr = NULL, *size = NULL, *phys_offset = NULL, *name = NULL;
@@ -817,10 +825,10 @@ void libxl__domain_suspend(libxl__egc *egc,
libxl__domain_suspend_state *dss)
domain_suspend_done(egc, dss, rc);
}
-void libxl__xc_domain_save_done(libxl__egc *egc,
- libxl__domain_suspend_state *dss,
+void libxl__xc_domain_save_done(libxl__egc *egc, void *dss_void,
int rc, int retval, int errnoval)
{
+ libxl__domain_suspend_state *dss = dss_void;
STATE_AO_GC(dss->ao);
/* Convenience aliases */
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index a06cc65..d86d204 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -54,6 +54,7 @@
#include "libxl.h"
#include "_libxl_paths.h"
+#include "_libxl_save_msgs.h"
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
#define _hidden __attribute__((visibility("hidden")))
@@ -752,8 +753,6 @@ _hidden int libxl__domain_rename(libxl__gc *gc, uint32_t
domid,
const char *old_name, const char *new_name,
xs_transaction_t trans);
-_hidden int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
- uint32_t size, void *data);
_hidden const char *libxl__device_model_savefile(libxl__gc *gc, uint32_t
domid);
_hidden int libxl__domain_save_device_model(libxl__gc *gc, uint32_t domid, int
fd);
_hidden void libxl__userdata_destroyall(libxl__gc *gc, uint32_t domid);
@@ -1704,6 +1703,36 @@ _hidden void
libxl__datacopier_kill(libxl__datacopier_state *dc);
_hidden int libxl__datacopier_start(libxl__datacopier_state *dc);
+/*----- Save/restore helper (used by creation and suspend) -----*/
+
+typedef struct libxl__save_helper_state {
+ /* public, caller of run_helper initialises */
+ libxl__ao *ao;
+ uint32_t domid;
+ int (*recv_callback)(const unsigned char *msg, uint32_t len, void *user);
+ void (*completion_callback)(libxl__egc *egc, void *caller_state,
+ int rc, int retval, int errnoval);
+ void *caller_state;
+ int need_results; /* set to 0 or 1 by caller of run_helper;
+ * if set to 1 then the ultimate caller's
+ * results function must set it to 0 */
+ /* private */
+ int rc;
+ int completed; /* retval/errnoval valid iff completed */
+ int retval, errnoval; /* from xc_domain_save / xc_domain_restore */
+ libxl__carefd *pipes[2]; /* 0 = helper's stdin, 1 = helper's stdout */
+ libxl__ev_fd readable;
+ libxl__ev_child child;
+ const char *stdin_what, *stdout_what;
+} libxl__save_helper_state;
+
+typedef struct libxl__save_helper_callback_user {
+ libxl__egc *egc;
+ libxl__save_helper_state *shs;
+ void *caller_state;
+} libxl__save_helper_callback_user;
+
+
/*----- Domain suspend (save) state structure -----*/
typedef struct libxl__domain_suspend_state libxl__domain_suspend_state;
@@ -1726,6 +1755,7 @@ struct libxl__domain_suspend_state {
int suspend_eventchn;
int hvm;
int guest_responded;
+ libxl__save_helper_state shs;
};
@@ -1822,6 +1852,7 @@ struct libxl__domain_create_state {
libxl__stub_dm_spawn_state dmss;
/* If we're not doing stubdom, we use only dmss.dm,
* for the non-stubdom device model. */
+ libxl__save_helper_state shs;
};
/*----- Domain suspend (save) functions -----*/
@@ -1838,13 +1869,9 @@ _hidden void libxl__xc_domain_save(libxl__egc*,
libxl__domain_suspend_state*,
/* If rc==0 then retval is the return value from xc_domain_save
* and errnoval is the errno value it provided.
* If rc!=0, retval and errnoval are undefined. */
-_hidden void libxl__xc_domain_save_done(libxl__egc*,
- libxl__domain_suspend_state*,
+_hidden void libxl__xc_domain_save_done(libxl__egc*, void *dss_void,
int rc, int retval, int errnoval);
-_hidden int libxl__domain_suspend_common_callback(void *data);
-_hidden int libxl__domain_suspend_common_switch_qemu_logdirty
- (int domid, unsigned int enable, void *data);
_hidden int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
uint32_t *len, void *data);
@@ -1853,13 +1880,11 @@ _hidden int libxl__toolstack_save(uint32_t domid,
uint8_t **buf,
_hidden void libxl__xc_domain_restore(libxl__egc *egc,
libxl__domain_create_state *dcs,
int hvm, int pae, int superpages,
- int no_incr_generationid,
- xc_toolstack_restore_cb*);
+ int no_incr_generationid);
/* If rc==0 then retval is the return value from xc_domain_save
* and errnoval is the errno value it provided.
* If rc!=0, retval and errnoval are undefined. */
-_hidden void libxl__xc_domain_restore_done(libxl__egc *egc,
- libxl__domain_create_state *dcs,
+_hidden void libxl__xc_domain_restore_done(libxl__egc *egc, void *dcs_void,
int rc, int retval, int errnoval);
diff --git a/tools/libxl/libxl_save_callout.c b/tools/libxl/libxl_save_callout.c
index 2355cc0..efc84d8 100644
--- a/tools/libxl/libxl_save_callout.c
+++ b/tools/libxl/libxl_save_callout.c
@@ -16,10 +16,22 @@
#include "libxl_internal.h"
+static void run_helper(libxl__egc *egc, libxl__save_helper_state *shs,
+ const char *mode_arg, int data_fd,
+ const unsigned long *argnums, int num_argnums);
+
+static void helper_failed(libxl__egc*, libxl__save_helper_state *shs, int rc);
+static void helper_stdout_readable(libxl__egc *egc, libxl__ev_fd *ev,
+ int fd, short events, short revents);
+static void helper_exited(libxl__egc *egc, libxl__ev_child *ch,
+ pid_t pid, int status);
+static void helper_done(libxl__egc *egc, libxl__save_helper_state *shs);
+
+/*----- entrypoints -----*/
+
void libxl__xc_domain_restore(libxl__egc *egc, libxl__domain_create_state *dcs,
int hvm, int pae, int superpages,
- int no_incr_generationid,
- xc_toolstack_restore_cb *toolstack_restore)
+ int no_incr_generationid)
{
STATE_AO_GC(dcs->ao);
@@ -28,17 +40,23 @@ void libxl__xc_domain_restore(libxl__egc *egc,
libxl__domain_create_state *dcs,
const int restore_fd = dcs->restore_fd;
libxl__domain_build_state *const state = &dcs->build_state;
- struct restore_callbacks callbacks;
- callbacks.toolstack_restore = toolstack_restore;
- callbacks.data = gc;
+ const unsigned long argnums[] = {
+ restore_fd, domid,
+ state->store_port,
+ state->store_domid, state->console_port,
+ state->console_domid,
+ hvm, pae, superpages, no_incr_generationid,
+ };
- int r = xc_domain_restore(CTX->xch, restore_fd, domid,
- state->store_port, &state->store_mfn,
- state->store_domid, state->console_port,
- &state->console_mfn, state->console_domid,
- hvm, pae, superpages, no_incr_generationid,
- &state->vm_generationid_addr, &callbacks);
- libxl__xc_domain_restore_done(egc, dcs, 0, r, errno);
+ dcs->shs.ao = ao;
+ dcs->shs.domid = domid;
+ dcs->shs.recv_callback = libxl_srm_callout_received_restore;
+ dcs->shs.completion_callback = libxl__xc_domain_restore_done;
+ dcs->shs.caller_state = dcs;
+ dcs->shs.need_results = 1;
+
+ run_helper(egc, &dcs->shs, "--restore-domain", restore_fd,
+ argnums, ARRAY_SIZE(argnums));
}
void libxl__xc_domain_save(libxl__egc *egc, libxl__domain_suspend_state *dss,
@@ -46,17 +64,267 @@ void libxl__xc_domain_save(libxl__egc *egc,
libxl__domain_suspend_state *dss,
unsigned long vm_generationid_addr)
{
STATE_AO_GC(dss->ao);
- struct save_callbacks callbacks;
- int r;
-
- memset(&callbacks, 0, sizeof(callbacks));
- callbacks.suspend = libxl__domain_suspend_common_callback;
- callbacks.switch_qemu_logdirty =
- libxl__domain_suspend_common_switch_qemu_logdirty;
- callbacks.toolstack_save = libxl__toolstack_save;
- callbacks.data = dss;
-
- r = xc_domain_save(CTX->xch, dss->fd, dss->domid, 0, 0, xcflags,
&callbacks,
- hvm, vm_generationid_addr);
- libxl__xc_domain_save_done(egc, dss, 0, r, errno);
+ int r, rc;
+ uint32_t toolstack_data_len;
+
+ /* Resources we need to free */
+ uint8_t *toolstack_data_buf = 0;
+ FILE *toolstack_data_file = 0;
+
+ r = libxl__toolstack_save(dss->domid, &toolstack_data_buf,
+ &toolstack_data_len, dss);
+ if (r) { rc = ERROR_FAIL; goto out; }
+
+ toolstack_data_file = tmpfile();
+ if (!toolstack_data_file) {
+ LOGE(ERROR, "cannot create toolstack data tmpfile");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+ int toolstack_data_fd = fileno(toolstack_data_file);
+
+ r = libxl_write_exactly(CTX, toolstack_data_fd,
+ toolstack_data_buf, toolstack_data_len,
+ "toolstack data tmpfile", 0);
+ if (r) { rc = ERROR_FAIL; goto out; }
+
+ r = lseek(toolstack_data_fd, 0, SEEK_SET);
+ if (r) {
+ LOGE(ERROR, "rewind toolstack data tmpfile");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ const unsigned long argnums[] = {
+ dss->fd, dss->domid, 0, 0, xcflags, hvm, vm_generationid_addr,
+ toolstack_data_fd, toolstack_data_len,
+ };
+
+ dss->shs.ao = ao;
+ dss->shs.domid = dss->domid;
+ dss->shs.recv_callback = libxl_srm_callout_received_save;
+ dss->shs.completion_callback = libxl__xc_domain_save_done;
+ dss->shs.caller_state = dss;
+ dss->shs.need_results = 0;
+
+ run_helper(egc, &dss->shs, "--save-domain", dss->fd,
+ argnums, ARRAY_SIZE(argnums));
+ return;
+
+ out:
+ free(toolstack_data_buf);
+ if (toolstack_data_file) fclose(toolstack_data_file);
+
+ libxl__xc_domain_save_done(egc, dss, rc, 0, 0);
+}
+
+
+/*----- helper execution -----*/
+
+static void run_helper(libxl__egc *egc, libxl__save_helper_state *shs,
+ const char *mode_arg, int data_fd,
+ const unsigned long *argnums, int num_argnums)
+{
+ STATE_AO_GC(shs->ao);
+ const char *args[2 + num_argnums];
+ const char **arg = args;
+ int i, rc;
+
+ /* Resources we must free */
+ libxl__carefd *childs_pipes[2] = { 0,0 };
+
+ /* Convenience aliases */
+ const uint32_t domid = shs->domid;
+
+ shs->rc = 0;
+ shs->completed = 0;
+ shs->pipes[0] = shs->pipes[1] = 0;
+ libxl__ev_fd_init(&shs->readable);
+ libxl__ev_child_init(&shs->child);
+
+ shs->stdin_what = GCSPRINTF("domain %"PRIu32" save/restore helper"
+ " stdin pipe", domid);
+ shs->stdout_what = GCSPRINTF("domain %"PRIu32" save/restore helper"
+ " stdout pipe", domid);
+
+ *arg++ = LIBEXEC "/" "libxl-save-helper";
+ *arg++ = mode_arg;
+ for (i=0; i<num_argnums; i++)
+ *arg++ = GCSPRINTF("%lu", argnums[i]);
+ *arg++ = 0;
+ assert(arg == args + ARRAY_SIZE(args));
+
+ libxl__carefd_begin();
+ for (i=0; i<2; i++) {
+ int fds[2];
+ if (libxl_pipe(CTX,fds)) { rc = ERROR_FAIL; goto out; }
+ childs_pipes[i] = libxl__carefd_record(CTX, fds[i]);
+ shs->pipes[i] = libxl__carefd_record(CTX, fds[!i]);
+ }
+ libxl__carefd_unlock();
+
+ pid_t pid = libxl__ev_child_fork(gc, &shs->child, helper_exited);
+ if (!pid) {
+ libxl_fd_set_cloexec(CTX, data_fd, 0);
+ libxl__exec(libxl__carefd_fd(childs_pipes[0]),
+ libxl__carefd_fd(childs_pipes[1]),
+ -1,
+ args[0], (char**)args);
+ }
+
+ libxl__carefd_close(childs_pipes[0]);
+ libxl__carefd_close(childs_pipes[1]);
+
+ rc = libxl__ev_fd_register(gc, &shs->readable, helper_stdout_readable,
+ libxl__carefd_fd(shs->pipes[1]),
POLLIN|POLLPRI);
+ if (rc) goto out;
+ return;
+
+ out:
+ libxl__carefd_close(childs_pipes[0]);
+ libxl__carefd_close(childs_pipes[1]);
+ helper_failed(egc, shs, rc);;
+}
+
+static void helper_failed(libxl__egc *egc, libxl__save_helper_state *shs,
+ int rc)
+{
+ STATE_AO_GC(shs->ao);
+
+ if (!shs->rc)
+ shs->rc = rc;
+
+ if (!libxl__ev_child_inuse(&shs->child)) {
+ helper_done(egc, shs);
+ return;
+ }
+
+ int r = kill(shs->child.pid, SIGKILL);
+ if (r) LOGE(WARN, "failed to kill save/restore helper [%lu]",
+ (unsigned long)shs->child.pid);
+}
+
+static void helper_stdout_readable(libxl__egc *egc, libxl__ev_fd *ev,
+ int fd, short events, short revents)
+{
+ libxl__save_helper_state *shs = CONTAINER_OF(ev, *shs, readable);
+ STATE_AO_GC(shs->ao);
+ int rc, errnoval;
+
+ if (revents & POLLPRI) {
+ LOG(ERROR, "%s signaled POLLERR", shs->stdout_what);
+ rc = ERROR_FAIL;
+ out:
+ /* this is here because otherwise we bypass the decl of msg[] */
+ helper_failed(egc, shs, rc);
+ return;
+ }
+
+ uint32_t msglen;
+ errnoval = libxl_read_exactly(CTX, fd, &msglen, sizeof(msglen),
+ shs->stdout_what, "ipc msg header");
+ if (errnoval) { rc = ERROR_FAIL; goto out; }
+
+ unsigned char msg[msglen];
+ errnoval = libxl_read_exactly(CTX, fd, msg, msglen,
+ shs->stdout_what, "ipc msg body");
+ if (errnoval) { rc = ERROR_FAIL; goto out; }
+
+ libxl__save_helper_callback_user user = { egc, shs, shs->caller_state };
+ shs->recv_callback(msg, msglen, &user);
+ return;
+}
+
+static void helper_exited(libxl__egc *egc, libxl__ev_child *ch,
+ pid_t pid, int status)
+{
+ libxl__save_helper_state *shs = CONTAINER_OF(ch, *shs, child);
+ STATE_AO_GC(shs->ao);
+
+ /* Convenience aliases */
+ const uint32_t domid = shs->domid;
+
+ const char *what =
+ GCSPRINTF("domain %"PRIu32" save/restore helper", domid);
+
+ if (status) {
+ libxl_report_child_exitstatus(CTX, XTL_ERROR, what, pid, status);
+ shs->rc = ERROR_FAIL;
+ }
+
+ if (shs->need_results) {
+ if (!shs->rc)
+ LOG(ERROR,"%s exited without providing results",what);
+ shs->rc = ERROR_FAIL;
+ }
+
+ if (!shs->completed) {
+ if (!shs->rc)
+ LOG(ERROR,"%s exited without signaling completion",what);
+ shs->rc = ERROR_FAIL;
+ }
+
+ helper_done(egc, shs);
+ return;
+}
+
+static void helper_done(libxl__egc *egc, libxl__save_helper_state *shs)
+{
+ STATE_AO_GC(shs->ao);
+
+ libxl__ev_fd_deregister(gc, &shs->readable);
+ libxl__carefd_close(shs->pipes[0]); shs->pipes[0] = 0;
+ libxl__carefd_close(shs->pipes[1]); shs->pipes[1] = 0;
+ assert(!libxl__ev_child_inuse(&shs->child));
+
+ shs->completion_callback(egc, shs->caller_state,
+ shs->rc, shs->retval, shs->errnoval);
+}
+
+/*----- generic helpers for the autogenerated code -----*/
+
+void libxl_srm_callout_sendreply(int r, void *user_void)
+{
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__save_helper_state *shs = user->shs;
+ libxl__egc *egc = user->egc;
+ STATE_AO_GC(shs->ao);
+ int errnoval;
+
+ errnoval = libxl_write_exactly(CTX, libxl__carefd_fd(shs->pipes[0]),
+ &r, sizeof(r), shs->stdin_what,
+ "callback return value");
+ if (errnoval)
+ helper_failed(egc, shs, ERROR_FAIL);
+}
+
+void libxl_srm_callout_callback_log(uint32_t level, uint32_t errnoval,
+ const char *context, const char *formatted, void *user_void)
+{
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__save_helper_state *shs = user->shs;
+ STATE_AO_GC(shs->ao);
+ xtl_log(CTX->lg, level, errnoval, context, "%s", formatted);
+}
+
+void libxl_srm_callout_callback_progress(const char *context,
+ const char *doing_what, unsigned long done,
+ unsigned long total, void *user_void)
+{
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__save_helper_state *shs = user->shs;
+ STATE_AO_GC(shs->ao);
+ xtl_progress(CTX->lg, context, doing_what, done, total);
+}
+
+void libxl_srm_callout_callback_complete(int retval, int errnoval,
+ void *user_void)
+{
+ libxl__save_helper_callback_user *user = user_void;
+ libxl__save_helper_state *shs = user->shs;
+ STATE_AO_GC(shs->ao);
+
+ shs->completed = 1;
+ shs->retval = retval;
+ shs->errnoval = errnoval;
}
diff --git a/tools/libxl/libxl_save_helper.c b/tools/libxl/libxl_save_helper.c
new file mode 100644
index 0000000..79081dd
--- /dev/null
+++ b/tools/libxl/libxl_save_helper.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2012 Citrix Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+/*
+ * The libxl-save-helper utility speaks a protocol to its caller for
+ * the callbacks. The protocol is as follows.
+ *
+ * The helper talks on stdin and stdout, in binary in machine
+ * endianness. The helper speaks first, and only when it has a
+ * callback to make. It writes a 32-bit number being the message
+ * length, and then the message body.
+ *
+ * Each message starts with a 32-bit number indicating which of the
+ * messages it is, and then some arguments in a binary marshalled form.
+ * If the callback does not need a reply (it returns void), the helper
+ * just continues. Otherwise the helper waits for its caller to send a
+ * single int which is to be the return value from the callback.
+ *
+ * Where feasible the stubs and callbacks have prototypes identical to
+ * those required by xc_domain_save and xc_domain_restore, so that the
+ * autogenerated functions can be used/provided directly.
+ *
+ * The actual messages are in the array @msgs in libxl_save_msgs_gen.pl
+ */
+
+#include "libxl_osdeps.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <assert.h>
+
+#include "libxl.h"
+
+#include "xenctrl.h"
+#include "xenguest.h"
+#include "_libxl_save_msgs.h"
+
+/*----- globals -----*/
+
+static const char *program = "libxl-save-helper";
+static xentoollog_logger *logger;
+static xc_interface *xch;
+
+/*----- error handling -----*/
+
+static void fail(int errnoval, const char *fmt, ...)
+ __attribute__((noreturn,format(printf,2,3)));
+static void fail(int errnoval, const char *fmt, ...)
+{
+ va_list al;
+ va_start(al,fmt);
+ xtl_logv(logger,XTL_ERROR,errnoval,program,fmt,al);
+ exit(-1);
+}
+
+static int read_exactly(int fd, void *buf, size_t len)
+/* returns 0 if we get eof, even if we got it midway through; 1 if ok */
+{
+ while (len) {
+ ssize_t r = read(fd, buf, len);
+ if (r<=0) return r;
+ assert(r <= len);
+ len -= r;
+ buf = (char*)buf + r;
+ }
+ return 1;
+}
+
+static void *xmalloc(size_t sz)
+{
+ if (!sz) return 0;
+ void *r = malloc(sz);
+ if (!r) { perror("memory allocation failed"); exit(-1); }
+ return r;
+}
+
+/*----- logger -----*/
+
+typedef struct {
+ xentoollog_logger vtable;
+} xentoollog_logger_tellparent;
+
+static void tellparent_vmessage(xentoollog_logger *logger_in,
+ xentoollog_level level,
+ int errnoval,
+ const char *context,
+ const char *format,
+ va_list al)
+{
+ char *formatted;
+ int r = vasprintf(&formatted, format, al);
+ if (r < 0) { perror("memory allocation failed during logging"); exit(-1); }
+ libxl_srm_helper_stub_log(level, errnoval, context, formatted, 0);
+ free(formatted);
+}
+
+static void tellparent_progress(struct xentoollog_logger *logger_in,
+ const char *context,
+ const char *doing_what, int percent,
+ unsigned long done, unsigned long total)
+{
+ libxl_srm_helper_stub_progress(context, doing_what, done, total, 0);
+}
+
+static void tellparent_destroy(struct xentoollog_logger *logger_in)
+{
+ abort();
+}
+
+static xentoollog_logger_tellparent *createlogger_tellparent(void)
+{
+ xentoollog_logger_tellparent newlogger;
+ return XTL_NEW_LOGGER(tellparent, newlogger);
+}
+
+/*----- helper functions called by autogenerated stubs -----*/
+
+unsigned char * libxl_srm_helper_allocbuf(int len, void *user)
+{
+ return xmalloc(len);
+}
+
+void libxl_srm_helper_transmit(unsigned char *msg_freed, int len, void *user)
+{
+ while (len) {
+ int r = write(1, msg_freed, len);
+ if (r<0) { perror("write"); exit(-1); }
+ assert(r >= 0);
+ assert(r <= len);
+ len -= r;
+ msg_freed += r;
+ }
+ free(msg_freed);
+}
+
+int libxl_srm_helper_getreply(void *user)
+{
+ int v;
+ int r = read_exactly(0, &v, sizeof(v));
+ if (r<=0) exit(-2);
+ return v;
+}
+
+/*----- other callbacks -----*/
+
+static int toolstack_save_fd;
+static uint32_t toolstack_save_len;
+
+static int toolstack_save_cb(uint32_t domid, uint8_t **buf,
+ uint32_t *len, void *data)
+{
+ assert(toolstack_save_fd > 0);
+
+ *buf = xmalloc(toolstack_save_len);
+ int r = read_exactly(toolstack_save_fd, *buf, toolstack_save_len);
+ if (r<0) fail(errno,"read toolstack data");
+ if (r==0) fail(0,"read toolstack data eof");
+
+ toolstack_save_fd = -1;
+ return 0;
+}
+
+static struct save_callbacks helper_save_callbacks = {
+ .suspend = libxl_srm_helper_stub_suspend,
+ .postcopy = libxl_srm_helper_stub_postcopy,
+ .checkpoint = libxl_srm_helper_stub_checkpoint,
+ .switch_qemu_logdirty = libxl_srm_helper_stub_switch_qemu_logdirty,
+ .toolstack_save = toolstack_save_cb,
+ .data = NULL,
+};
+
+static struct restore_callbacks helper_restore_callbacks = {
+ .toolstack_restore = libxl_srm_helper_stub_toolstack_restore,
+ .data = NULL,
+};
+
+static void startup(const char *op) {
+ xentoollog_logger *logger = (xentoollog_logger*)createlogger_tellparent();
+ if (!logger) {
+ fprintf(stderr, "%s: cannot initialise logger\n", program);
+ exit(-1);
+ }
+
+ xtl_log(logger,XTL_DEBUG,0,program,"starting %s",op);
+
+ xch = xc_interface_open(logger,logger,0);
+ if (!xch) fail(errno,"xc_interface_open failed");
+}
+
+static void complete(int retval) {
+ int errnoval = errno;
+ xtl_log(logger,XTL_DEBUG,errnoval,program,"complete r=%d",retval);
+ libxl_srm_helper_stub_complete(retval,errnoval,0);
+ exit(0);
+}
+
+int main(int argc, char **argv)
+{
+ int r;
+
+#define NEXTARG (++argv, assert(*argv), *argv)
+
+ const char *mode = *++argv;
+ assert(mode);
+
+ if (!strcmp(mode,"--save-domain")) {
+
+ int io_fd = atoi(NEXTARG);
+ uint32_t dom = strtoul(NEXTARG,0,10);
+ uint32_t max_iters = strtoul(NEXTARG,0,10);
+ uint32_t max_factor = strtoul(NEXTARG,0,10);
+ uint32_t flags = strtoul(NEXTARG,0,10);
+ int hvm = atoi(NEXTARG);
+ unsigned long genidad = strtoul(NEXTARG,0,10);
+ toolstack_save_fd = atoi(NEXTARG);
+ toolstack_save_len = strtoul(NEXTARG,0,10);
+ assert(!*++argv);
+
+ startup("save");
+ r = xc_domain_save(xch, io_fd, dom, max_iters, max_factor, flags,
+ &helper_save_callbacks, hvm, genidad);
+ complete(r);
+
+ } else if (!strcmp(mode,"--restore-domain")) {
+
+ int io_fd = atoi(NEXTARG);
+ uint32_t dom = strtoul(NEXTARG,0,10);
+ unsigned store_evtchn = strtoul(NEXTARG,0,10);
+ domid_t store_domid = strtoul(NEXTARG,0,10);
+ unsigned console_evtchn = strtoul(NEXTARG,0,10);
+ domid_t console_domid = strtoul(NEXTARG,0,10);
+ unsigned int hvm = strtoul(NEXTARG,0,10);
+ unsigned int pae = strtoul(NEXTARG,0,10);
+ int superpages = strtoul(NEXTARG,0,10);
+ int no_incr_genidad = strtoul(NEXTARG,0,10);
+ assert(!*++argv);
+
+ unsigned long store_mfn = 0;
+ unsigned long console_mfn = 0;
+ unsigned long genidad = 0;
+
+ startup("restore");
+ r = xc_domain_restore(xch, io_fd, dom, store_evtchn, &store_mfn,
+ store_domid, console_evtchn, &console_mfn,
+ console_domid, hvm, pae, superpages,
+ no_incr_genidad, &genidad,
+ &helper_restore_callbacks);
+ libxl_srm_helper_stub_restore_results(store_mfn,console_mfn,genidad,0);
+ complete(r);
+
+ } else {
+ assert(!"unexpected mode argument");
+ }
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/tools/libxl/libxl_save_msgs_gen.pl
b/tools/libxl/libxl_save_msgs_gen.pl
new file mode 100755
index 0000000..9960fdc
--- /dev/null
+++ b/tools/libxl/libxl_save_msgs_gen.pl
@@ -0,0 +1,305 @@
+#!/usr/bin/perl -w
+
+use warnings;
+use strict;
+use POSIX;
+
+
+our @msgs = (
+ [ 1, 'sr',0, "log", [qw(uint32_t level
+ uint32_t errnoval
+ STRING context
+ STRING formatted)] ],
+ [ 2, 'sr',0, "progress", [qw(STRING context
+ STRING doing_what),
+ 'unsigned long', 'done',
+ 'unsigned long', 'total'] ],
+ [ 3, 's', 1, "suspend", [] ],
+ [ 4, 's', 1, "postcopy", [] ],
+ [ 5, 's', 1, "checkpoint", [] ],
+ [ 6, 's', 1, "switch_qemu_logdirty", [qw(int domid
+ unsigned enable)] ],
+ [ 7, 'r', 1, "toolstack_restore", [qw(uint32_t domid
+ BLOCK tsdata)] ],
+ [ 8, 'r', 0, "restore_results", ['unsigned long', 'store_mfn',
+ 'unsigned long', 'console_mfn',
+ 'unsigned long', 'genidad'] ],
+ [ 9, 'sr',0, "complete", [qw(int retval
+ int errnoval)] ],
+);
+
+#----------------------------------------
+
+our %func;
+our %func_ah;
+our @outfuncs;
+our %out_decls;
+our %out_body;
+our %msgnum_used;
+
+die unless @ARGV==1;
+die if $ARGV[0] =~ m/^-/;
+
+our ($intendedout) = @ARGV;
+
+my $declprefix = '';
+
+foreach my $ah (qw(callout helper)) {
+ $out_body{$ah} .= <<END;
+#include <assert.h>
+#include <string.h>
+#include <stdint.h>
+#include <limits.h>
+
+#include "_libxl_save_msgs.h"
+
+END
+}
+
+sub f_decl ($$$$) {
+ my ($name, $ah, $c_rtype, $c_decl) = @_;
+ $out_decls{$name} = "${declprefix}$c_rtype $name$c_decl;\n";
+ $func{$name} = "$c_rtype $name$c_decl\n{\n" . ($func{$name} || '');
+ $func_ah{$name} = $ah;
+}
+
+sub f_more ($$) {
+ my ($name, $addbody) = @_;
+ $func{$name} ||= '';
+ $func{$name} .= $addbody;
+ push @outfuncs, $name;
+}
+
+our $callback = "libxl_srm_callout_callback";
+our $receiveds = "libxl_srm_callout_received";
+our $sendreply = "libxl_srm_callout_sendreply";
+
+f_decl($sendreply, 'callout', 'void', "(int r, void *user)");
+
+our $encode = "libxl_srm_helper_stub";
+our $allocbuf = "libxl_srm_helper_allocbuf";
+our $transmit = "libxl_srm_helper_transmit";
+our $getreply = "libxl_srm_helper_getreply";
+
+f_decl($allocbuf, 'helper', 'unsigned char *', '(int len, void *user)');
+f_decl($transmit, 'helper', 'void',
+ '(unsigned char *msg_freed, int len, void *user)');
+f_decl($getreply, 'helper', 'int', '(void *user)');
+
+sub typeid ($) { my ($t) = @_; $t =~ s/\W/_/; return $t; };
+
+$out_body{'callout'} .= <<END;
+static int bytes_get(const unsigned char **msg,
+ const unsigned char *const endmsg,
+ void *result, int rlen)
+{
+ if (endmsg - *msg < rlen) return 0;
+ memcpy(result,*msg,rlen);
+ *msg += rlen;
+ return 1;
+}
+
+END
+$out_body{'helper'} .= <<END;
+static void bytes_put(unsigned char *const buf, int *len,
+ const void *value, int vlen)
+{
+ assert(vlen < INT_MAX/2 - *len);
+ if (buf)
+ memcpy(buf + *len, value, vlen);
+ *len += vlen;
+}
+
+END
+
+foreach my $simpletype (qw(int uint32_t unsigned), 'unsigned long') {
+ my $typeid = typeid($simpletype);
+ $out_body{'callout'} .= <<END;
+static int ${typeid}_get(const unsigned char **msg,
+ const unsigned char *const endmsg,
+ $simpletype *result)
+{
+ return bytes_get(msg, endmsg, result, sizeof(*result));
+}
+
+END
+ $out_body{'helper'} .= <<END;
+static void ${typeid}_put(unsigned char *const buf, int *len,
+ const $simpletype value)
+{
+ bytes_put(buf, len, &value, sizeof(value));
+}
+
+END
+}
+
+$out_body{'callout'} .= <<END;
+static int BLOCK_get(const unsigned char **msg,
+ const unsigned char *const endmsg,
+ const uint8_t **result, uint32_t *result_size)
+{
+ if (!uint32_t_get(msg,endmsg,result_size)) return 0;
+ if (endmsg - *msg < *result_size) return 0;
+ *result = (const void*)*msg;
+ *msg += *result_size;
+ return 1;
+}
+
+static int STRING_get(const unsigned char **msg,
+ const unsigned char *const endmsg,
+ const char **result)
+{
+ const uint8_t *data;
+ uint32_t datalen;
+ if (!BLOCK_get(msg,endmsg,&data,&datalen)) return 0;
+ if (datalen == 0) return 0;
+ if (data[datalen-1] != '\\0') return 0;
+ *result = (const void*)data;
+ return 1;
+}
+
+END
+$out_body{'helper'} .= <<END;
+static void BLOCK_put(unsigned char *const buf,
+ int *len,
+ const uint8_t *bytes, uint32_t size)
+{
+ uint32_t_put(buf, len, size);
+ bytes_put(buf, len, bytes, size);
+}
+
+static void STRING_put(unsigned char *const buf,
+ int *len,
+ const char *string)
+{
+ size_t slen = strlen(string);
+ assert(slen < INT_MAX / 4);
+ assert(slen < (uint32_t)0x40000000);
+ BLOCK_put(buf, len, (const void*)string, slen+1);
+}
+
+END
+
+foreach my $sr (qw(save restore)) {
+ f_decl("${receiveds}_${sr}", 'callout', 'int',
+ "(const unsigned char *msg, uint32_t len, void *user)");
+
+ f_more("${receiveds}_${sr}",
+" const unsigned char *const endmsg = msg + len;
+ uint32_t mtype;
+ if (!uint32_t_get(&msg,endmsg,&mtype)) return 0;
+ switch (mtype) {
+
+");
+}
+
+foreach my $msginfo (@msgs) {
+ my ($msgnum, $inwhich, $hasreply, $name, $args) = @$msginfo;
+ die if $msgnum_used{$msgnum}++;
+
+ my $f_more_recv = sub {
+ f_more("${receiveds}_save", $_[0]) if $inwhich =~ m/s/;
+ f_more("${receiveds}_restore", $_[0]) if $inwhich =~ m/r/;
+ };
+
+ $f_more_recv->(" case $msgnum: { /* $name */\n");
+ if ($hasreply) {
+ $f_more_recv->(" int r;\n");
+ }
+
+ my $c_rtype = $hasreply ? 'int' : 'void';
+ my $c_decl = '(';
+ my $c_callback_args = '';
+
+ f_more("${encode}_$name",
+" unsigned char *buf = 0;
+ int len = 0, allocd = 0;
+
+ for (;;) {
+ uint32_t_put(buf, &len, $msgnum /* $name */);
+");
+
+ my @args = @$args;
+ my $c_recv = '';
+ my ($argtype, $arg);
+ while (($argtype, $arg, @args) = @args) {
+ my $typeid = typeid($argtype);
+ my $c_args = "$arg";
+ my $c_get_args = "&$arg";
+ if ($argtype eq 'STRING') {
+ $c_decl .= "const char *$arg, ";
+ $f_more_recv->(" const char *$arg;\n");
+ } elsif ($argtype eq 'BLOCK') {
+ $c_decl .= "const uint8_t *$arg, uint32_t ${arg}_size, ";
+ $c_args .= ", ${arg}_size";
+ $c_get_args .= ",&${arg}_size";
+ $f_more_recv->(" const uint8_t *$arg;\n".
+ " uint32_t ${arg}_size;\n");
+ } else {
+ $c_decl .= "$argtype $arg, ";
+ $f_more_recv->(" $argtype $arg;\n");
+ }
+ $c_callback_args .= "$c_args, ";
+ $c_recv.=
+ " if (!${typeid}_get(&msg,endmsg,$c_get_args)) return 0;\n";
+ f_more("${encode}_$name", " ${typeid}_put(buf, &len, $c_args);\n");
+ }
+ $f_more_recv->($c_recv);
+ $c_decl .= "void *user)";
+ $c_callback_args .= "user";
+
+ $f_more_recv->(" if (msg != endmsg) return 0;\n");
+ my $c_make_callback = "${callback}_$name($c_callback_args)";
+ if (!$hasreply) {
+ $f_more_recv->(" $c_make_callback;\n");
+ } else {
+ $f_more_recv->(" r = $c_make_callback;\n".
+ " $sendreply(r, user);\n");
+ f_decl($sendreply, 'callout', 'void', '(int r, void *user)');
+ }
+ $f_more_recv->(" return 1;\n }\n\n");
+ f_decl("${callback}_$name", 'callout', $c_rtype, $c_decl);
+ f_decl("${encode}_$name", 'helper', $c_rtype, $c_decl);
+ f_more("${encode}_$name",
+" if (buf) break;
+ buf = libxl_srm_helper_allocbuf(len, user);
+ assert(buf);
+ }
+ assert(len == allocd);
+ libxl_srm_helper_transmit(buf, len, user);
+");
+ if ($hasreply) {
+ f_more("${encode}_$name",
+ " return libxl_srm_helper_getreply(user);\n");
+ }
+}
+
+foreach my $sr (qw(save restore)) {
+f_more("${receiveds}_${sr}",
+" default:
+ return 0;
+ }
+");
+}
+
+foreach my $name (@outfuncs) {
+ next unless defined $func{$name};
+ $func{$name} .= "}\n";
+ $out_body{$func_ah{$name}} .= "$func{$name}\n";
+ delete $func{$name};
+}
+
+print "/* AUTOGENERATED by $0 DO NOT EDIT */\n\n" or die $!;
+
+if ($intendedout =~ m/\.h$/) {
+ foreach my $decl (sort values %out_decls) {
+ print $decl or die $!;
+ }
+} elsif ($intendedout =~ m/([a-z]+)\.c$/) {
+ die $1 unless defined $out_body{$1};
+ print $out_body{$1} or die $!;
+} else {
+ die;
+}
+
+close STDOUT or die $!;
--
1.7.2.5
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