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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 11/21] libxl: prepare for asynchronous writing of qemu save file
* Combine the various calls to libxl__device_model_savefile into one
at the start of libxl__domain_suspend, storing the result in the
dss. Consequently a few functions take a dss instead of some or all
of their other arguments.
* Make libxl__domain_save_device_model's API into an asynchronous
style which takes a callback. The function is, however, still
synchronous; it will be made actually async in the next patch.
* Consequently make libxl__remus_domain_checkpoint_callback into an
asynchronous callback.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
tools/libxl/libxl_dom.c | 54 ++++++++++++++++++++++++++----------
tools/libxl/libxl_internal.h | 18 ++++++++++--
tools/libxl/libxl_save_msgs_gen.pl | 2 +-
3 files changed, 55 insertions(+), 19 deletions(-)
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 4cca846..e104744 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -703,11 +703,13 @@ static void switch_logdirty_done(libxl__egc *egc,
/*----- callbacks, called by xc_domain_save -----*/
-int libxl__domain_suspend_device_model(libxl__gc *gc, uint32_t domid)
+int libxl__domain_suspend_device_model(libxl__gc *gc,
+ libxl__domain_suspend_state *dss)
{
libxl_ctx *ctx = libxl__gc_owner(gc);
int ret = 0;
- const char *filename = libxl__device_model_savefile(gc, domid);
+ uint32_t const domid = dss->domid;
+ const char *const filename = dss->dm_savefile;
switch (libxl__device_model_version_running(gc, domid)) {
case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
@@ -876,7 +878,7 @@ int libxl__domain_suspend_common_callback(void *user)
guest_suspended:
if (dss->hvm) {
- ret = libxl__domain_suspend_device_model(gc, dss->domid);
+ ret = libxl__domain_suspend_device_model(gc, dss);
if (ret) {
LOG(ERROR, "libxl__domain_suspend_device_model failed ret=%d",
ret);
return 0;
@@ -991,19 +993,32 @@ static int libxl__remus_domain_resume_callback(void *data)
return 1;
}
-static int libxl__remus_domain_checkpoint_callback(void *data)
+/*----- remus asynchronous checkpoint callback -----*/
+
+static void remus_checkpoint_dm_saved(libxl__egc *egc,
+ libxl__domain_suspend_state *dss, int
rc);
+
+static void libxl__remus_domain_checkpoint_callback(void *data)
{
libxl__domain_suspend_state *dss = data;
+ libxl__egc *egc = dss->shs.egc;
STATE_AO_GC(dss->ao);
/* This would go into tailbuf. */
- if (dss->hvm &&
- libxl__domain_save_device_model(gc, dss->domid, dss->fd))
- return 0;
+ if (dss->hvm) {
+ libxl__domain_save_device_model(egc, dss, remus_checkpoint_dm_saved);
+ } else {
+ remus_checkpoint_dm_saved(egc, dss, 0);
+ }
+}
+static void remus_checkpoint_dm_saved(libxl__egc *egc,
+ libxl__domain_suspend_state *dss, int rc)
+{
/* TODO: Wait for disk and memory ack, release network buffer */
+ /* TODO: make this asynchronous */
usleep(dss->interval * 1000);
- return 1;
+ libxl__xc_domain_saverestore_async_callback_done(egc, &dss->shs, 1);
}
/*----- main code for suspending, in order of execution -----*/
@@ -1053,6 +1068,7 @@ void libxl__domain_suspend(libxl__egc *egc,
libxl__domain_suspend_state *dss)
dss->suspend_eventchn = -1;
dss->guest_responded = 0;
+ dss->dm_savefile = libxl__device_model_savefile(gc, domid);
if (r_info != NULL) {
dss->interval = r_info->interval;
@@ -1102,7 +1118,6 @@ void libxl__xc_domain_save_done(libxl__egc *egc, void
*dss_void,
/* Convenience aliases */
const libxl_domain_type type = dss->type;
- const uint32_t domid = dss->domid;
if (rc)
goto out;
@@ -1120,11 +1135,11 @@ void libxl__xc_domain_save_done(libxl__egc *egc, void
*dss_void,
}
if (type == LIBXL_DOMAIN_TYPE_HVM) {
- rc = libxl__domain_suspend_device_model(gc, domid);
+ rc = libxl__domain_suspend_device_model(gc, dss);
if (rc) goto out;
- rc = libxl__domain_save_device_model(gc, domid, dss->fd);
- if (rc) goto out;
+ libxl__domain_save_device_model(egc, dss, domain_suspend_done);
+ return;
}
rc = 0;
@@ -1133,14 +1148,22 @@ out:
domain_suspend_done(egc, dss, rc);
}
-int libxl__domain_save_device_model(libxl__gc *gc, uint32_t domid, int fd)
+void libxl__domain_save_device_model(libxl__egc *egc,
+ libxl__domain_suspend_state *dss,
+ libxl__save_device_model_cb *callback)
{
+ STATE_AO_GC(dss->ao);
int rc, fd2 = -1, c;
char buf[1024];
- const char *filename = libxl__device_model_savefile(gc, domid);
struct stat st;
uint32_t qemu_state_len;
+ dss->save_dm_callback = callback;
+
+ /* Convenience aliases */
+ const char *const filename = dss->dm_savefile;
+ const int fd = dss->fd;
+
if (stat(filename, &st) < 0)
{
LOG(ERROR, "Unable to stat qemu save file\n");
@@ -1182,7 +1205,8 @@ int libxl__domain_save_device_model(libxl__gc *gc,
uint32_t domid, int fd)
out:
if (fd2 >= 0) close(fd2);
unlink(filename);
- return rc;
+
+ dss->save_dm_callback(egc, dss, rc);
}
static void domain_suspend_done(libxl__egc *egc,
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 8b582e4..e95892a 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -824,10 +824,8 @@ _hidden int libxl__domain_rename(libxl__gc *gc, uint32_t
domid,
_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_suspend_device_model(libxl__gc *gc, uint32_t domid);
_hidden int libxl__domain_resume_device_model(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);
_hidden int libxl__domain_pvcontrol_available(libxl__gc *gc, uint32_t domid);
@@ -1869,6 +1867,8 @@ typedef struct libxl__domain_suspend_state
libxl__domain_suspend_state;
typedef void libxl__domain_suspend_cb(libxl__egc*,
libxl__domain_suspend_state*, int rc);
+typedef void libxl__save_device_model_cb(libxl__egc*,
+ libxl__domain_suspend_state*, int rc);
typedef struct libxl__logdirty_switch {
const char *cmd;
@@ -1895,9 +1895,12 @@ struct libxl__domain_suspend_state {
int hvm;
int xcflags;
int guest_responded;
+ const char *dm_savefile;
int interval; /* checkpoint interval (for Remus) */
libxl__save_helper_state shs;
libxl__logdirty_switch logdirty;
+ /* private for libxl__domain_save_device_model */
+ libxl__save_device_model_cb *save_dm_callback;
};
@@ -2053,6 +2056,15 @@ _hidden void libxl__xc_domain_restore(libxl__egc *egc,
_hidden void libxl__xc_domain_restore_done(libxl__egc *egc, void *dcs_void,
int rc, int retval, int errnoval);
+/* Each time the dm needs to be saved, we must call suspend and then save */
+_hidden int libxl__domain_suspend_device_model(libxl__gc *gc,
+ libxl__domain_suspend_state *dss);
+_hidden void libxl__domain_save_device_model(libxl__egc *egc,
+ libxl__domain_suspend_state *dss,
+ libxl__save_device_model_cb *callback);
+
+_hidden const char *libxl__device_model_savefile(libxl__gc *gc, uint32_t
domid);
+
/*
* Convenience macros.
diff --git a/tools/libxl/libxl_save_msgs_gen.pl
b/tools/libxl/libxl_save_msgs_gen.pl
index a9ac808..ee126c7 100755
--- a/tools/libxl/libxl_save_msgs_gen.pl
+++ b/tools/libxl/libxl_save_msgs_gen.pl
@@ -25,7 +25,7 @@ our @msgs = (
'unsigned long', 'total'] ],
[ 3, 'scxW', "suspend", [] ],
[ 4, 'scxW', "postcopy", [] ],
- [ 5, 'scxW', "checkpoint", [] ],
+ [ 5, 'scxA', "checkpoint", [] ],
[ 6, 'scxA', "switch_qemu_logdirty", [qw(int domid
unsigned enable)] ],
# toolstack_save done entirely `by hand'
--
1.7.2.5
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