Re: [Qemu-devel] [PATCH 3/7] QemuState: Add additional states

[Markus Armbruster]

Luiz Capitulino <address@hidden> writes:

> Currently, only vm_start() and vm_stop() change the VM state. That's,
> the state is only changed when starting or stopping the VM.
>
> This commit adds the qemu_state_set() function, making it possible
> to also do state transitions when qemu is stopped or running.
>
> Additional states are also added and the current state is stored.
> This is going to be used by the next commits.
>
> Signed-off-by: Luiz Capitulino <address@hidden>
> ---
>  cpus.c      |    1 +
>  migration.c |    8 +++++++-
>  sysemu.h    |   10 +++++++++-
>  vl.c        |   20 ++++++++++++++++++++
>  4 files changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/cpus.c b/cpus.c
> index ebbb8b9..48e6ca1 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -124,6 +124,7 @@ static void do_vm_stop(QemuState state)
>          cpu_disable_ticks();
>          vm_running = 0;
>          pause_all_vcpus();
> +        qemu_state_set(state);
>          vm_state_notify(0, state);
>          qemu_aio_flush();
>          bdrv_flush_all();
> diff --git a/migration.c b/migration.c
> index 9724ce0..8aacf64 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -72,8 +72,11 @@ void process_incoming_migration(QEMUFile *f)
>  
>      incoming_expected = false;
>  
> -    if (autostart)
> +    if (autostart) {
>          vm_start();
> +    } else {
> +        qemu_state_set(QSTATE_PRELAUNCH);
> +    }
>  }
>  
>  int do_migrate(Monitor *mon, const QDict *qdict, QObject **ret_data)
> @@ -394,6 +397,9 @@ void migrate_fd_put_ready(void *opaque)
>              }
>              state = MIG_STATE_ERROR;
>          }
> +        if (state == MIG_STATE_COMPLETED) {
> +            qemu_state_set(QSTATE_POSTMIGRATE);
> +        }
>          s->state = state;
>          notifier_list_notify(&migration_state_notifiers, NULL);
>      }
> diff --git a/sysemu.h b/sysemu.h
> index 2c3ea3d..32c9abb 100644
> --- a/sysemu.h
> +++ b/sysemu.h
> @@ -11,16 +11,22 @@
>  /* vl.c */
>  
>  typedef enum {
> +    QSTATE_NOSTATE,

QSTATE_NO_STATE?

>      QSTATE_DEBUG,         /* qemu is running under gdb */
> +    QSTATE_INMIGRATE,     /* paused waiting for an incoming migration */

QSTATE_IN_MIGRATE?

>      QSTATE_INTERROR,      /* paused due to an internal error */

QSTATE_PANICKED?

>      QSTATE_IOERROR,       /* paused due to an I/O error */

QSTATE_IO_ERROR?

>      QSTATE_PAUSED,        /* paused by the user (ie. the 'stop' command) */
> +    QSTATE_POSTMIGRATE,   /* paused following a successful migration */

QSTATE_POST_MIGRATE?

> +    QSTATE_PRELAUNCH,     /* qemu was started with -S and haven't started */

QSTATE_PRE_LAUNCH?

>      QSTATE_PREMIGRATE,    /* paused preparing to finish migrate */

QSTATE_PRE_MIGRATE?

>      QSTATE_RESTVM,        /* paused restoring the VM state */
> +    QSTATE_RESTVMFAILED,  /* paused due to a failed attempt to load state */

QSTATE_RESTVM_FAILED?

Consistently separating words by spaces became a general custom about
the tenth century A.D., and lasted until about 1957, when FORTRAN
abandoned the practice.
        -- Sun FORTRAN Reference Manual

>      QSTATE_RUNNING,       /* qemu is running */
>      QSTATE_SAVEVM,        /* paused saving VM state */
>      QSTATE_SHUTDOWN,      /* guest shut down and -no-shutdown is in use */
> -    QSTATE_WATCHDOG       /* watchdog fired and qemu is configured to pause 
> */
> +    QSTATE_WATCHDOG,      /* watchdog fired and qemu is configured to pause 
> */
> +    QSTATE_MAX
>  } QemuState;
>  
>  extern const char *bios_name;
> @@ -31,6 +37,8 @@ extern uint8_t qemu_uuid[];
>  int qemu_uuid_parse(const char *str, uint8_t *uuid);
>  #define UUID_FMT 
> "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
>  
> +QemuState qemu_state_get(void);
> +void qemu_state_set(QemuState state);
>  typedef struct vm_change_state_entry VMChangeStateEntry;
>  typedef void VMChangeStateHandler(void *opaque, int running, QemuState 
> state);
>  
> diff --git a/vl.c b/vl.c
> index faa7c5f..2619c8e 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -320,6 +320,22 @@ static int default_driver_check(QemuOpts *opts, void 
> *opaque)
>  }
>  
>  /***********************************************************/
> +/* QEMU state */
> +
> +static QemuState qemu_current_state = QSTATE_NOSTATE;
> +
> +QemuState qemu_state_get(void)
> +{
> +    return qemu_current_state;
> +}
> +
> +void qemu_state_set(QemuState state)
> +{
> +    assert(state < QSTATE_MAX);

Beware, comparison is signed if QemuState is signed (implementation
defined; QSTATE_MAX is int).

> +    qemu_current_state = state;
> +}
> +
> +/***********************************************************/
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