For now it only supports the "hibernate" mode, which suspends the
guest to disk.
This command will try to execute the scripts provided by the pm-utils
package. If that fails, it will try to suspend manually by writing
to the "/sys/power/state" file.
To reap terminated children, a new signal handler is installed to
catch SIGCHLD signals and a non-blocking call to waitpid() is done to
collect their exit statuses.
Signed-off-by: Luiz Capitulino<address@hidden>
---
qapi-schema-guest.json | 23 ++++++++++++++++++
qemu-ga.c | 17 ++++++++++++-
qga/guest-agent-commands.c | 55 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 94 insertions(+), 1 deletions(-)
diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json
index 5f8a18d..b151670 100644
--- a/qapi-schema-guest.json
+++ b/qapi-schema-guest.json
@@ -219,3 +219,26 @@
##
{ 'command': 'guest-fsfreeze-thaw',
'returns': 'int' }
+
+##
+# @guest-suspend
+#
+# Suspend guest execution by changing the guest's ACPI power state.
+#
+# This command tries to execute the scripts provided by the pm-utils
+# package. If they are not available, it will perform the suspend
+# operation by manually writing to a sysfs file.
+#
+# For the best results it's strongly recommended to have the pm-utils
+# package installed in the guest.
+#
+# @mode: 'hibernate' RAM content is saved to the disk and the guest is
+# powered off (this corresponds to ACPI S4)
+#
+# Notes: This is an asynchronous request. There's no guarantee a response
+# will be sent. Errors will be logged to guest's syslog. More modes are
+# expected in the future.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-suspend', 'data': { 'mode': 'str' } }
diff --git a/qemu-ga.c b/qemu-ga.c
index 98e4dfe..5b7a7a5 100644
--- a/qemu-ga.c
+++ b/qemu-ga.c
@@ -17,6 +17,7 @@
#include<getopt.h>
#include<termios.h>
#include<syslog.h>
+#include<sys/wait.h>
#include "qemu_socket.h"
#include "json-streamer.h"
#include "json-parser.h"
@@ -59,9 +60,15 @@ static void quit_handler(int sig)
}
}
+static void child_handler(int sig)
+{
+ int status;
+ waitpid(-1,&status, WNOHANG);
+}
+
static void register_signal_handlers(void)
{
- struct sigaction sigact;
+ struct sigaction sigact, sigact_chld;
int ret;
memset(&sigact, 0, sizeof(struct sigaction));
@@ -76,6 +83,14 @@ static void register_signal_handlers(void)
if (ret == -1) {
g_error("error configuring signal handler: %s", strerror(errno));
}
+
+ memset(&sigact_chld, 0, sizeof(struct sigaction));
+ sigact_chld.sa_handler = child_handler;
+ sigact_chld.sa_flags = SA_NOCLDSTOP;
+ ret = sigaction(SIGCHLD,&sigact_chld, NULL);
+ if (ret == -1) {
+ g_error("error configuring signal handler: %s", strerror(errno));
+ }
}
static void usage(const char *cmd)
diff --git a/qga/guest-agent-commands.c b/qga/guest-agent-commands.c
index a09c8ca..19f29c6 100644
--- a/qga/guest-agent-commands.c
+++ b/qga/guest-agent-commands.c
@@ -574,6 +574,61 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
}
#endif
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_suspend(const char *mode, Error **err)
+{
+ pid_t pid;
+ const char *pmutils_bin;
+
+ /* TODO implement 'sleep' and 'hybrid' modes once qemu is fixed to
+ support them */
+ if (strcmp(mode, "hibernate") == 0) {
+ pmutils_bin = "pm-hibernate";
+ } else {
+ error_set(err, QERR_INVALID_PARAMETER, "mode");
+ return;
+ }
+
+ pid = fork();
+ if (pid == 0) {
+ /* child */
+ int fd;
+
+ setsid();
+ fclose(stdin);
+ fclose(stdout);
+ fclose(stderr);
+
+ execlp(pmutils_bin, pmutils_bin, NULL);
+
+ /*
+ * The exec call should not return, if it does something went wrong.
+ * In this case we try to suspend manually if 'mode' is 'hibernate'
+ */
+ slog("could not execute %s: %s\n", pmutils_bin, strerror(errno));
+ slog("trying to suspend using the manual method...\n");
+
+ fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
+ if (fd< 0) {
+ slog("can't open file %s: %s\n", LINUX_SYS_STATE_FILE,
+ strerror(errno));
+ exit(1);
+ }
+
+ if (write(fd, "disk", 4)< 0) {
+ slog("can't write to %s: %s\n", LINUX_SYS_STATE_FILE,
+ strerror(errno));
+ exit(1);
+ }
+
+ exit(0);
+ } else if (pid< 0) {
+ error_set(err, QERR_UNDEFINED_ERROR);
+ return;
+ }
+}
+
/* register init/cleanup routines for stateful command groups */
void ga_command_state_init(GAState *s, GACommandState *cs)
{