Re: [PATCH v4 6/9] migration: wire up support for snapshot device selection

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Daniel P. Berrangé (berrange@redhat.com) wrote:
> Modify load_snapshot/save_snapshot to accept the device list and vmstate
> node name parameters previously added to the block layer.
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  include/migration/snapshot.h | 12 ++++++++++--
>  migration/savevm.c           | 24 ++++++++++++++----------
>  monitor/hmp-cmds.c           |  4 ++--
>  replay/replay-snapshot.c     |  4 ++--
>  softmmu/vl.c                 |  2 +-
>  5 files changed, 29 insertions(+), 17 deletions(-)
> 
> diff --git a/include/migration/snapshot.h b/include/migration/snapshot.h
> index d7db1174ef..b2c72e0a1b 100644
> --- a/include/migration/snapshot.h
> +++ b/include/migration/snapshot.h
> @@ -15,7 +15,15 @@
>  #ifndef QEMU_MIGRATION_SNAPSHOT_H
>  #define QEMU_MIGRATION_SNAPSHOT_H
>  
> -int save_snapshot(const char *name, bool overwrite, Error **errp);
> -int load_snapshot(const char *name, Error **errp);
> +#include "qapi/qapi-builtin-types.h"
> +
> +int save_snapshot(const char *name, bool overwrite,
> +                  const char *vmstate,
> +                  bool has_devices, strList *devices,
> +                  Error **errp);
> +int load_snapshot(const char *name,
> +                  const char *vmstate,
> +                  bool has_devices, strList *devices,
> +                  Error **errp);
>  
>  #endif
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 2025e3e579..b3d2ce7045 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -43,6 +43,8 @@
>  #include "qapi/error.h"
>  #include "qapi/qapi-commands-migration.h"
>  #include "qapi/qapi-commands-misc.h"
> +#include "qapi/clone-visitor.h"
> +#include "qapi/qapi-builtin-visit.h"
>  #include "qapi/qmp/qerror.h"
>  #include "qemu/error-report.h"
>  #include "sysemu/cpus.h"
> @@ -2658,7 +2660,8 @@ int qemu_load_device_state(QEMUFile *f)
>      return 0;
>  }
>  
> -int save_snapshot(const char *name, bool overwrite, Error **errp)
> +int save_snapshot(const char *name, bool overwrite, const char *vmstate,
> +                  bool has_devices, strList *devices, Error **errp)
>  {
>      BlockDriverState *bs;
>      QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
> @@ -2680,18 +2683,18 @@ int save_snapshot(const char *name, bool overwrite, Error **errp)
>          return ret;
>      }
>  
> -    if (!bdrv_all_can_snapshot(false, NULL, errp)) {
> +    if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
>          return ret;
>      }
>  
>      /* Delete old snapshots of the same name */
>      if (name && overwrite) {
> -        if (bdrv_all_delete_snapshot(name, false, NULL, errp) < 0) {
> +        if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) {
>              return ret;
>          }
>      }
>  
> -    bs = bdrv_all_find_vmstate_bs(NULL, false, NULL, errp);
> +    bs = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
>      if (bs == NULL) {
>          return ret;
>      }
> @@ -2757,7 +2760,7 @@ int save_snapshot(const char *name, bool overwrite, Error **errp)
>      aio_context_release(aio_context);
>      aio_context = NULL;
>  
> -    ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, false, NULL, errp);
> +    ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, has_devices, devices, errp);
>      if (ret < 0) {
>          goto the_end;
>      }
> @@ -2858,7 +2861,8 @@ void qmp_xen_load_devices_state(const char *filename, Error **errp)
>      migration_incoming_state_destroy();
>  }
>  
> -int load_snapshot(const char *name, Error **errp)
> +int load_snapshot(const char *name, const char *vmstate,
> +                  bool has_devices, strList *devices, Error **errp)
>  {
>      BlockDriverState *bs_vm_state;
>      QEMUSnapshotInfo sn;
> @@ -2873,15 +2877,15 @@ int load_snapshot(const char *name, Error **errp)
>          return -1;
>      }
>  
> -    if (!bdrv_all_can_snapshot(false, NULL, errp)) {
> +    if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
>          return -1;
>      }
> -    ret = bdrv_all_find_snapshot(name, false, NULL, errp);
> +    ret = bdrv_all_find_snapshot(name, has_devices, devices, errp);
>      if (ret < 0) {
>          return -1;
>      }
>  
> -    bs_vm_state = bdrv_all_find_vmstate_bs(NULL, false, NULL, errp);
> +    bs_vm_state = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
>      if (!bs_vm_state) {
>          return -1;
>      }
> @@ -2902,7 +2906,7 @@ int load_snapshot(const char *name, Error **errp)
>      /* Flush all IO requests so they don't interfere with the new state.  */
>      bdrv_drain_all_begin();
>  
> -    ret = bdrv_all_goto_snapshot(name, false, NULL, errp);
> +    ret = bdrv_all_goto_snapshot(name, has_devices, devices, errp);
>      if (ret < 0) {
>          goto err_drain;
>      }
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index c1b8533d0c..1191aac3ae 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -1121,7 +1121,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
>  
>      vm_stop(RUN_STATE_RESTORE_VM);
>  
> -    if (load_snapshot(name, &err) == 0 && saved_vm_running) {
> +    if (load_snapshot(name, NULL, false, NULL, &err) == 0 && saved_vm_running) {
>          vm_start();
>      }
>      hmp_handle_error(mon, err);
> @@ -1131,7 +1131,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
>  {
>      Error *err = NULL;
>  
> -    save_snapshot(qdict_get_try_str(qdict, "name"), true, &err);
> +    save_snapshot(qdict_get_try_str(qdict, "name"), true, NULL, false, NULL, &err);
>      hmp_handle_error(mon, err);
>  }
>  
> diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c
> index 8e7ff97d11..8ed09177b5 100644
> --- a/replay/replay-snapshot.c
> +++ b/replay/replay-snapshot.c
> @@ -77,13 +77,13 @@ void replay_vmstate_init(void)
>  
>      if (replay_snapshot) {
>          if (replay_mode == REPLAY_MODE_RECORD) {
> -            if (save_snapshot(replay_snapshot, true, &err) != 0) {
> +            if (save_snapshot(replay_snapshot, true, NULL, false, NULL, &err) != 0) {
>                  error_report_err(err);
>                  error_report("Could not create snapshot for icount record");
>                  exit(1);
>              }
>          } else if (replay_mode == REPLAY_MODE_PLAY) {
> -            if (load_snapshot(replay_snapshot, &err) != 0) {
> +            if (load_snapshot(replay_snapshot, NULL, false, NULL, &err) != 0) {
>                  error_report_err(err);
>                  error_report("Could not load snapshot for icount replay");
>                  exit(1);
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index f7b103467c..820d380229 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -4459,7 +4459,7 @@ void qemu_init(int argc, char **argv, char **envp)
>      register_global_state();
>      if (loadvm) {
>          Error *local_err = NULL;
> -        if (load_snapshot(loadvm, &local_err) < 0) {
> +        if (load_snapshot(loadvm, NULL, false, NULL, &local_err) < 0) {
>              error_report_err(local_err);
>              autostart = 0;
>              exit(1);
> -- 
> 2.26.2
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK