Re: [Qemu-devel] [PATCH 1/8] Introduce the VMStatus type

[Anthony Liguori <anthony@codemonkey.ws>]

On 07/05/2011 01:17 PM, Luiz Capitulino wrote:
> We need to track the VM status so that QMP can report it to clients.
>
> This commit adds the VMStatus type and related functions. The
> vm_status_set() function is used to keep track of the current
> VM status.
>
> The current statuses are:

Which states are terminal, and what's the proper procedure to recover 
from non-terminal states?  Is it cont or system_reset followed by cont?

>
>      - debug: guest is running under gdb
>      - inmigrate: guest is paused waiting for an incoming migration
>      - postmigrate: guest is paused following a successful migration
>      - internal-error: Fatal internal error that prevents further guest
>                  execution
>      - load-state-error: guest is paused following a failed 'loadvm'
>      - io-error: the last IOP has failed and the device is configured
>                  to pause on I/O errors
>      - watchdog-error: the watchdog action is configured to pause and
>                        has been triggered
>      - paused: guest has been paused via the 'stop' command
>      - prelaunch: QEMU was started with -S and guest has not started
>      - running: guest is actively running
>      - shutdown: guest is shut down (and -no-shutdown is in use)

Regards,

Anthony Liguori

>
> Signed-off-by: Luiz Capitulino<lcapitulino@redhat.com>
> ---
>   gdbstub.c       |    4 ++++
>   hw/ide/core.c   |    1 +
>   hw/scsi-disk.c  |    1 +
>   hw/virtio-blk.c |    1 +
>   hw/watchdog.c   |    1 +
>   kvm-all.c       |    1 +
>   migration.c     |    3 +++
>   monitor.c       |    5 ++++-
>   sysemu.h        |   19 +++++++++++++++++++
>   vl.c            |   37 +++++++++++++++++++++++++++++++++++++
>   10 files changed, 72 insertions(+), 1 deletions(-)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index c085a5a..61b700a 100644
> --- a/gdbstub.c
> +++ b/gdbstub.c
> @@ -2358,6 +2358,7 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
>       s->state = RS_SYSCALL;
>   #ifndef CONFIG_USER_ONLY
>       vm_stop(VMSTOP_DEBUG);
> +    vm_status_set(VMST_DEBUG);
>   #endif
>       s->state = RS_IDLE;
>       va_start(va, fmt);
> @@ -2432,6 +2433,7 @@ static void gdb_read_byte(GDBState *s, int ch)
>           /* when the CPU is running, we cannot do anything except stop
>              it when receiving a char */
>           vm_stop(VMSTOP_USER);
> +        vm_status_set(VMST_DEBUG);
>       } else
>   #endif
>       {
> @@ -2694,6 +2696,7 @@ static void gdb_chr_event(void *opaque, int event)
>       switch (event) {
>       case CHR_EVENT_OPENED:
>           vm_stop(VMSTOP_USER);
> +        vm_status_set(VMST_DEBUG);
>           gdb_has_xml = 0;
>           break;
>       default:
> @@ -2735,6 +2738,7 @@ static void gdb_sigterm_handler(int signal)
>   {
>       if (vm_running) {
>           vm_stop(VMSTOP_USER);
> +        vm_status_set(VMST_DEBUG);
>       }
>   }
>   #endif
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index ca17a43..bf9df41 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -523,6 +523,7 @@ static int ide_handle_rw_error(IDEState *s, int error, int op)
>           s->bus->error_status = op;
>           bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
>           vm_stop(VMSTOP_DISKFULL);
> +        vm_status_set(VMST_IOERROR);
>       } else {
>           if (op&  BM_STATUS_DMA_RETRY) {
>               dma_buf_commit(s, 0);
> diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
> index a8c7372..66037fd 100644
> --- a/hw/scsi-disk.c
> +++ b/hw/scsi-disk.c
> @@ -216,6 +216,7 @@ static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type)
>
>           bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
>           vm_stop(VMSTOP_DISKFULL);
> +        vm_status_set(VMST_IOERROR);
>       } else {
>           if (type == SCSI_REQ_STATUS_RETRY_READ) {
>               scsi_req_data(&r->req, 0);
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index 91e0394..bf70200 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -79,6 +79,7 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
>           s->rq = req;
>           bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
>           vm_stop(VMSTOP_DISKFULL);
> +        vm_status_set(VMST_IOERROR);
>       } else {
>           virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
>           bdrv_mon_event(s->bs, BDRV_ACTION_REPORT, is_read);
> diff --git a/hw/watchdog.c b/hw/watchdog.c
> index 1c900a1..d130cbb 100644
> --- a/hw/watchdog.c
> +++ b/hw/watchdog.c
> @@ -133,6 +133,7 @@ void watchdog_perform_action(void)
>       case WDT_PAUSE:             /* same as 'stop' command in monitor */
>           watchdog_mon_event("pause");
>           vm_stop(VMSTOP_WATCHDOG);
> +        vm_status_set(VMST_WATCHDOG);
>           break;
>
>       case WDT_DEBUG:
> diff --git a/kvm-all.c b/kvm-all.c
> index cbc2532..aee9e0a 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -1015,6 +1015,7 @@ int kvm_cpu_exec(CPUState *env)
>       if (ret<  0) {
>           cpu_dump_state(env, stderr, fprintf, CPU_DUMP_CODE);
>           vm_stop(VMSTOP_PANIC);
> +        vm_status_set(VMST_INTERROR);
>       }
>
>       env->exit_request = 0;
> diff --git a/migration.c b/migration.c
> index af3a1f2..674792f 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -394,6 +394,9 @@ void migrate_fd_put_ready(void *opaque)
>               }
>               state = MIG_STATE_ERROR;
>           }
> +        if (state == MIG_STATE_COMPLETED) {
> +            vm_status_set(VMST_POSTMIGRATE);
> +        }
>           s->state = state;
>           notifier_list_notify(&migration_state_notifiers);
>       }
> diff --git a/monitor.c b/monitor.c
> index 67ceb46..1cb3191 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -1258,6 +1258,7 @@ static void do_singlestep(Monitor *mon, const QDict *qdict)
>   static int do_stop(Monitor *mon, const QDict *qdict, QObject **ret_data)
>   {
>       vm_stop(VMSTOP_USER);
> +    vm_status_set(VMST_PAUSED);
>       return 0;
>   }
>
> @@ -2782,7 +2783,9 @@ static void do_loadvm(Monitor *mon, const QDict *qdict)
>
>       vm_stop(VMSTOP_LOADVM);
>
> -    if (load_vmstate(name) == 0&&  saved_vm_running) {
> +    if (load_vmstate(name)<  0) {
> +        vm_status_set(VMST_LOADERROR);
> +    } else if (saved_vm_running) {
>           vm_start();
>       }
>   }
> diff --git a/sysemu.h b/sysemu.h
> index d3013f5..7308ac5 100644
> --- a/sysemu.h
> +++ b/sysemu.h
> @@ -77,6 +77,25 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f);
>   void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f);
>   int qemu_loadvm_state(QEMUFile *f);
>
> +typedef enum {
> +    VMST_NOSTATUS,
> +    VMST_DEBUG,
> +    VMST_INMIGRATE,
> +    VMST_POSTMIGRATE,
> +    VMST_INTERROR,
> +    VMST_IOERROR,
> +    VMST_LOADERROR,
> +    VMST_PAUSED,
> +    VMST_PRELAUNCH,
> +    VMST_RUNNING,
> +    VMST_SHUTDOWN,
> +    VMST_WATCHDOG,
> +    VMST_MAX,
> +} VMStatus;
> +
> +void vm_status_set(VMStatus s);
> +const char *vm_status_get_name(void);
> +
>   /* SLIRP */
>   void do_info_slirp(Monitor *mon);
>
> diff --git a/vl.c b/vl.c
> index fcd7395..fb7208f 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -309,6 +309,37 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
>   }
>
>   /***********************************************************/
> +/* VMStatus */
> +
> +static const char *const vm_status_name[VMST_MAX] = {
> +    [VMST_DEBUG] = "debug",
> +    [VMST_INMIGRATE] = "inmigrate",
> +    [VMST_POSTMIGRATE] = "postmigrate",
> +    [VMST_INTERROR] = "internal-error",
> +    [VMST_IOERROR] = "io-error",
> +    [VMST_LOADERROR] = "load-state-error",
> +    [VMST_PAUSED] = "paused",
> +    [VMST_PRELAUNCH] = "prelaunch",
> +    [VMST_RUNNING] = "running",
> +    [VMST_SHUTDOWN] = "shutdown",
> +    [VMST_WATCHDOG] = "watchdog-error",
> +};
> +
> +static VMStatus qemu_vm_status = VMST_NOSTATUS;
> +
> +void vm_status_set(VMStatus s)
> +{
> +    assert(s>  VMST_NOSTATUS&&  s<  VMST_MAX);
> +    qemu_vm_status = s;
> +}
> +
> +const char *vm_status_get_name(void)
> +{
> +    assert(qemu_vm_status>  VMST_NOSTATUS&&  qemu_vm_status<  VMST_MAX);
> +    return vm_status_name[qemu_vm_status];
> +}
> +
> +/***********************************************************/
>   /* real time host monotonic timer */
>
>   /***********************************************************/
> @@ -1150,6 +1181,7 @@ void vm_start(void)
>           vm_state_notify(1, 0);
>           resume_all_vcpus();
>           monitor_protocol_event(QEVENT_RESUME, NULL);
> +        vm_status_set(VMST_RUNNING);
>       }
>   }
>
> @@ -1392,12 +1424,14 @@ static void main_loop(void)
>
>           if (qemu_debug_requested()) {
>               vm_stop(VMSTOP_DEBUG);
> +            vm_status_set(VMST_DEBUG);
>           }
>           if (qemu_shutdown_requested()) {
>               qemu_kill_report();
>               monitor_protocol_event(QEVENT_SHUTDOWN, NULL);
>               if (no_shutdown) {
>                   vm_stop(VMSTOP_SHUTDOWN);
> +                vm_status_set(VMST_SHUTDOWN);
>                   no_shutdown = 0;
>               } else
>                   break;
> @@ -2476,6 +2510,7 @@ int main(int argc, char **argv, char **envp)
>                   break;
>               case QEMU_OPTION_S:
>                   autostart = 0;
> +                vm_status_set(VMST_PRELAUNCH);
>                   break;
>   	    case QEMU_OPTION_k:
>   		keyboard_layout = optarg;
> @@ -3307,11 +3342,13 @@ int main(int argc, char **argv, char **envp)
>       qemu_system_reset(VMRESET_SILENT);
>       if (loadvm) {
>           if (load_vmstate(loadvm)<  0) {
> +            vm_status_set(VMST_LOADERROR);
>               autostart = 0;
>           }
>       }
>
>       if (incoming) {
> +        vm_status_set(VMST_INMIGRATE);
>           int ret = qemu_start_incoming_migration(incoming);
>           if (ret<  0) {
>               fprintf(stderr, "Migration failed. Exit code %s(%d), exiting.\n",