Re: [PATCH V7 12/29] vl: helper to request re-exec

[Steven Sistare]

On 3/9/2022 9:16 AM, Marc-André Lureau wrote:
> On Wed, Dec 22, 2021 at 11:52 PM Steve Sistare  > wrote:
> 
> Add a qemu_system_exec_request() hook that causes the main loop to exit 
> and
> re-exec qemu using the specified arguments.
> 
> Signed-off-by: Steve Sistare  >
> ---
>  include/sysemu/runstate.h |  1 +
>  softmmu/runstate.c        | 21 +
>  2 files changed, 22 insertions(+)
> 
> diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h
> index b655c7b..198211b 100644
> --- a/include/sysemu/runstate.h
> +++ b/include/sysemu/runstate.h
> @@ -57,6 +57,7 @@ void qemu_system_wakeup_enable(WakeupReason reason, 
> bool enabled);
>  void qemu_register_wakeup_notifier(Notifier *notifier);
>  void qemu_register_wakeup_support(void);
>  void qemu_system_shutdown_request(ShutdownCause reason);
> +void qemu_system_exec_request(const strList *args);
>  void qemu_system_powerdown_request(void);
>  void qemu_register_powerdown_notifier(Notifier *notifier);
>  void qemu_register_shutdown_notifier(Notifier *notifier);
> diff --git a/softmmu/runstate.c b/softmmu/runstate.c
> index 3d344c9..309a4bf 100644
> --- a/softmmu/runstate.c
> +++ b/softmmu/runstate.c
> @@ -38,6 +38,7 @@
>  #include "monitor/monitor.h"
>  #include "net/net.h"
>  #include "net/vhost_net.h"
> +#include "qapi/util.h"
>  #include "qapi/error.h"
>  #include "qapi/qapi-commands-run-state.h"
>  #include "qapi/qapi-events-run-state.h"
> @@ -355,6 +356,7 @@ static NotifierList wakeup_notifiers =
>  static NotifierList shutdown_notifiers =
>      NOTIFIER_LIST_INITIALIZER(shutdown_notifiers);
>  static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
> +static char **exec_argv;
> 
>  ShutdownCause qemu_shutdown_requested_get(void)
>  {
> @@ -371,6 +373,11 @@ static int qemu_shutdown_requested(void)
>      return qatomic_xchg(&shutdown_requested, SHUTDOWN_CAUSE_NONE);
>  }
> 
> +static int qemu_exec_requested(void)
> +{
> +    return exec_argv != NULL;
> +}
> +
>  static void qemu_kill_report(void)
>  {
>      if (!qtest_driver() && shutdown_signal) {
> @@ -641,6 +648,13 @@ void qemu_system_shutdown_request(ShutdownCause 
> reason)
>      qemu_notify_event();
>  }
> 
> +void qemu_system_exec_request(const strList *args)
> +{
> +    exec_argv = strv_from_strList(args);
> 
> 
> I would rather make it take a GStrv, since that's what it actually uses.
> 
> I would also check if argv[0] is set (or document the expected behaviour).

Will do, thanks.

- Steve

> +    shutdown_requested = 1;
> +    qemu_notify_event();
> +}
> +
>  static void qemu_system_powerdown(void)
>  {
>      qapi_event_send_powerdown();
> @@ -689,6 +703,13 @@ static bool main_loop_should_exit(void)
>      }
>      request = qemu_shutdown_requested();
>      if (request) {
> +
> +        if (qemu_exec_requested()) {
> +            execvp(exec_argv[0], exec_argv);
> +            error_report("execvp %s failed: %s", exec_argv[0], 
> strerror(errno));
> +            g_strfreev(exec_argv);
> +            exec_argv = NULL;
> +        }
>          qemu_kill_report();
>          qemu_system_shutdown(request);
>          if (shutdown_action == SHUTDOWN_ACTION_PAUSE) {
> -- 
> 1.8.3.1
> 
> 
> 
> 
> -- 
> Marc-André Lureau

Re: [PATCH V7 12/29] vl: helper to request re-exec

[Marc-André Lureau]

On Wed, Dec 22, 2021 at 11:52 PM Steve Sistare 
wrote:

> Add a qemu_system_exec_request() hook that causes the main loop to exit and
> re-exec qemu using the specified arguments.
>
> Signed-off-by: Steve Sistare 
> ---
>  include/sysemu/runstate.h |  1 +
>  softmmu/runstate.c| 21 +
>  2 files changed, 22 insertions(+)
>
> diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h
> index b655c7b..198211b 100644
> --- a/include/sysemu/runstate.h
> +++ b/include/sysemu/runstate.h
> @@ -57,6 +57,7 @@ void qemu_system_wakeup_enable(WakeupReason reason, bool
> enabled);
>  void qemu_register_wakeup_notifier(Notifier *notifier);
>  void qemu_register_wakeup_support(void);
>  void qemu_system_shutdown_request(ShutdownCause reason);
> +void qemu_system_exec_request(const strList *args);
>  void qemu_system_powerdown_request(void);
>  void qemu_register_powerdown_notifier(Notifier *notifier);
>  void qemu_register_shutdown_notifier(Notifier *notifier);
> diff --git a/softmmu/runstate.c b/softmmu/runstate.c
> index 3d344c9..309a4bf 100644
> --- a/softmmu/runstate.c
> +++ b/softmmu/runstate.c
> @@ -38,6 +38,7 @@
>  #include "monitor/monitor.h"
>  #include "net/net.h"
>  #include "net/vhost_net.h"
> +#include "qapi/util.h"
>  #include "qapi/error.h"
>  #include "qapi/qapi-commands-run-state.h"
>  #include "qapi/qapi-events-run-state.h"
> @@ -355,6 +356,7 @@ static NotifierList wakeup_notifiers =
>  static NotifierList shutdown_notifiers =
>  NOTIFIER_LIST_INITIALIZER(shutdown_notifiers);
>  static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
> +static char **exec_argv;
>
>  ShutdownCause qemu_shutdown_requested_get(void)
>  {
> @@ -371,6 +373,11 @@ static int qemu_shutdown_requested(void)
>  return qatomic_xchg(&shutdown_requested, SHUTDOWN_CAUSE_NONE);
>  }
>
> +static int qemu_exec_requested(void)
> +{
> +return exec_argv != NULL;
> +}
> +
>  static void qemu_kill_report(void)
>  {
>  if (!qtest_driver() && shutdown_signal) {
> @@ -641,6 +648,13 @@ void qemu_system_shutdown_request(ShutdownCause
> reason)
>  qemu_notify_event();
>  }
>
> +void qemu_system_exec_request(const strList *args)
> +{
> +exec_argv = strv_from_strList(args);
>

I would rather make it take a GStrv, since that's what it actually uses.

I would also check if argv[0] is set (or document the expected behaviour).


> +shutdown_requested = 1;
> +qemu_notify_event();
> +}
> +
>  static void qemu_system_powerdown(void)
>  {
>  qapi_event_send_powerdown();
> @@ -689,6 +703,13 @@ static bool main_loop_should_exit(void)
>  }
>  request = qemu_shutdown_requested();
>  if (request) {
> +
> +if (qemu_exec_requested()) {
> +execvp(exec_argv[0], exec_argv);
> +error_report("execvp %s failed: %s", exec_argv[0],
> strerror(errno));
> +g_strfreev(exec_argv);
> +exec_argv = NULL;
> +}
>  qemu_kill_report();
>  qemu_system_shutdown(request);
>  if (shutdown_action == SHUTDOWN_ACTION_PAUSE) {
> --
> 1.8.3.1
>
>
>

-- 
Marc-André Lureau

[PATCH V7 12/29] vl: helper to request re-exec

[Steve Sistare]

Add a qemu_system_exec_request() hook that causes the main loop to exit and
re-exec qemu using the specified arguments.

Signed-off-by: Steve Sistare 
---
 include/sysemu/runstate.h |  1 +
 softmmu/runstate.c| 21 +
 2 files changed, 22 insertions(+)

diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h
index b655c7b..198211b 100644
--- a/include/sysemu/runstate.h
+++ b/include/sysemu/runstate.h
@@ -57,6 +57,7 @@ void qemu_system_wakeup_enable(WakeupReason reason, bool 
enabled);
 void qemu_register_wakeup_notifier(Notifier *notifier);
 void qemu_register_wakeup_support(void);
 void qemu_system_shutdown_request(ShutdownCause reason);
+void qemu_system_exec_request(const strList *args);
 void qemu_system_powerdown_request(void);
 void qemu_register_powerdown_notifier(Notifier *notifier);
 void qemu_register_shutdown_notifier(Notifier *notifier);
diff --git a/softmmu/runstate.c b/softmmu/runstate.c
index 3d344c9..309a4bf 100644
--- a/softmmu/runstate.c
+++ b/softmmu/runstate.c
@@ -38,6 +38,7 @@
 #include "monitor/monitor.h"
 #include "net/net.h"
 #include "net/vhost_net.h"
+#include "qapi/util.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-run-state.h"
 #include "qapi/qapi-events-run-state.h"
@@ -355,6 +356,7 @@ static NotifierList wakeup_notifiers =
 static NotifierList shutdown_notifiers =
 NOTIFIER_LIST_INITIALIZER(shutdown_notifiers);
 static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
+static char **exec_argv;
 
 ShutdownCause qemu_shutdown_requested_get(void)
 {
@@ -371,6 +373,11 @@ static int qemu_shutdown_requested(void)
 return qatomic_xchg(&shutdown_requested, SHUTDOWN_CAUSE_NONE);
 }
 
+static int qemu_exec_requested(void)
+{
+return exec_argv != NULL;
+}
+
 static void qemu_kill_report(void)
 {
 if (!qtest_driver() && shutdown_signal) {
@@ -641,6 +648,13 @@ void qemu_system_shutdown_request(ShutdownCause reason)
 qemu_notify_event();
 }
 
+void qemu_system_exec_request(const strList *args)
+{
+exec_argv = strv_from_strList(args);
+shutdown_requested = 1;
+qemu_notify_event();
+}
+
 static void qemu_system_powerdown(void)
 {
 qapi_event_send_powerdown();
@@ -689,6 +703,13 @@ static bool main_loop_should_exit(void)
 }
 request = qemu_shutdown_requested();
 if (request) {
+
+if (qemu_exec_requested()) {
+execvp(exec_argv[0], exec_argv);
+error_report("execvp %s failed: %s", exec_argv[0], 
strerror(errno));
+g_strfreev(exec_argv);
+exec_argv = NULL;
+}
 qemu_kill_report();
 qemu_system_shutdown(request);
 if (shutdown_action == SHUTDOWN_ACTION_PAUSE) {
-- 
1.8.3.1