Backport a patch from xenserver.

xenvm send a SIGUSR1 to save the qemu context.

diff --git a/master/series b/master/series
index a7b238df8db331f170ab13d69039186c74d625b8..39cd30b62710e37c6ce15335273519c8885aafbc 100644 (file)
--- a/master/series
+++ b/master/series
@@ -2,6 +2,7 @@ ioemu-compil
 add-config-audio
 xenstore-watch-callbacks
 dm-ready
+suspend-by-signal
 
 battery-management
 oem-features

diff --git a/master/suspend-by-signal b/master/suspend-by-signal
new file mode 100644 (file)
index 0000000..632a006
--- /dev/null
+++ b/master/suspend-by-signal
@@ -0,0 +1,92 @@
+diff --git a/i386-dm/helper2.c b/i386-dm/helper2.c
+index 969241f..681bd86 100644
+--- a/i386-dm/helper2.c
++++ b/i386-dm/helper2.c
+@@ -566,7 +566,7 @@ int main_loop(void)
+     qemu_set_fd_handler(xenstore_fd(), xenstore_process_event, NULL, NULL);
+ 
+     while (1) {
+-        while (!(vm_running && xen_pause_requested))
++        while (!(vm_running && (xen_pause_requested || suspend_requested)))
+             /* Wait up to 10 msec. */
+             main_loop_wait(10);
+ 
+@@ -582,6 +582,9 @@ int main_loop(void)
+         do_savevm(qemu_file);
+         free(qemu_file);
+ 
++        if (suspend_requested)
++            return 0;
++
+         xenstore_record_dm_state("paused");
+ 
+         /* Wait to be allowed to continue */
+diff --git a/qemu-xen.h b/qemu-xen.h
+index c45bf9f..395b7c9 100644
+--- a/qemu-xen.h
++++ b/qemu-xen.h
+@@ -34,6 +34,8 @@ void     qemu_invalidate_map_cache(void);
+ #define mapcache_lock()   ((void)0)
+ #define mapcache_unlock() ((void)0)
+ 
++extern int suspend_requested;
++
+ /* helper2.c */
+ extern long time_offset;
+ void timeoffset_get(void);
+diff --git a/vl.c b/vl.c
+index b273c75..5c437e0 100644
+--- a/vl.c
++++ b/vl.c
+@@ -3369,6 +3369,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
+ 
+ #endif /* !CONFIG_DM */
+ 
++void suspend(int sig)
++{
++    fprintf(stderr, "suspend sig handler called with requested=%d!\n",
++            suspend_requested);
++    if (sig != SIGUSR1)
++        fprintf(stderr, "suspend signal dismatch, get sig=%d!\n", sig);
++    suspend_requested = 1;
++}
++
+ void qemu_service_io(void)
+ {
+     CPUState *env = cpu_single_env;
+@@ -3611,6 +3620,7 @@ static QEMUResetEntry *first_reset_entry;
+ static int reset_requested;
+ static int shutdown_requested;
+ static int powerdown_requested;
++int suspend_requested = 0;
+ 
+ int qemu_shutdown_requested(void)
+ {
+@@ -6049,6 +6059,27 @@ int main(int argc, char **argv, char **envp)
+ 
+     xenstore_dm_finished_startup();
+ 
++#ifndef CONFIG_STUBDOM
++    /* register signal for the suspend request when save */
++    {
++        struct sigaction act;
++        sigset_t set;
++        act.sa_handler = suspend;
++        act.sa_flags = SA_RESTART;
++        sigemptyset(&act.sa_mask);
++
++        sigaction(SIGUSR1, &act, NULL);
++
++        /* control panel mask some signals when spawn qemu, need unmask here*/
++        sigemptyset(&set);
++        sigaddset(&set, SIGUSR1);
++        sigaddset(&set, SIGTERM);
++        if (sigprocmask(SIG_UNBLOCK, &set, NULL) == -1)
++            fprintf(stderr, "unblock signal fail, possible issue for HVM save!\n");
++
++    }
++#endif
++
+     main_loop();
+     quit_timers();
+     net_cleanup();