Re: [Qemu-devel] [PATCH v2 06/10] replay: vmstate for replay module

[Paolo Bonzini]

On 15/09/2016 11:01, Pavel Dovgalyuk wrote:
> This patch introduces vmstate for replay data structures.
> It allows saving and loading vmstate while replaying.
> 
> Signed-off-by: Pavel Dovgalyuk <address@hidden>
> ---
>  include/sysemu/replay.h  |    4 ++++
>  replay/replay-internal.h |    2 ++
>  replay/replay-snapshot.c |   40 ++++++++++++++++++++++++++++++++++++++++
>  vl.c                     |    1 +
>  4 files changed, 47 insertions(+)
> 
> diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h
> index aa378ce..1123fc2 100644
> --- a/include/sysemu/replay.h
> +++ b/include/sysemu/replay.h
> @@ -147,6 +147,10 @@ void replay_net_packet_event(ReplayNetState *rns, 
> unsigned flags,
>  
>  /* VM state operations */
>  
> +/* Registers replay VMState.
> +   Should be called before virtual devices initialization
> +   to make cached timers available for post_load functions. */
> +void replay_vmstate_register(void);

Can this be done simply in replay_configure?

Paolo

>  /*! Called at the start of execution.
>      Loads or saves initial vmstate depending on execution mode. */
>  void replay_vmstate_init(void);
> diff --git a/replay/replay-internal.h b/replay/replay-internal.h
> index 3147d66..9bc4a29 100644
> --- a/replay/replay-internal.h
> +++ b/replay/replay-internal.h
> @@ -67,6 +67,8 @@ typedef struct ReplayState {
>      unsigned int data_kind;
>      /*! Flag which indicates that event is not processed yet. */
>      unsigned int has_unread_data;
> +    /*! Temporary variable for saving current log offset. */
> +    uint64_t file_offset;
>  } ReplayState;
>  extern ReplayState replay_state;
>  
> diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c
> index a48c6fc..4933bdd 100644
> --- a/replay/replay-snapshot.c
> +++ b/replay/replay-snapshot.c
> @@ -17,6 +17,46 @@
>  #include "sysemu/sysemu.h"
>  #include "monitor/monitor.h"
>  #include "qapi/qmp/qstring.h"
> +#include "migration/vmstate.h"
> +
> +static void replay_pre_save(void *opaque)
> +{
> +    ReplayState *state = opaque;
> +    state->file_offset = ftello64(replay_file);
> +}
> +
> +static int replay_post_load(void *opaque, int version_id)
> +{
> +    ReplayState *state = opaque;
> +    fseeko64(replay_file, state->file_offset, SEEK_SET);
> +    /* If this was a vmstate, saved in recording mode,
> +       we need to initialize replay data fields. */
> +    replay_fetch_data_kind();
> +
> +    return 0;
> +}
> +
> +static const VMStateDescription vmstate_replay = {
> +    .name = "replay",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .pre_save = replay_pre_save,
> +    .post_load = replay_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_INT64_ARRAY(cached_clock, ReplayState, REPLAY_CLOCK_COUNT),
> +        VMSTATE_UINT64(current_step, ReplayState),
> +        VMSTATE_INT32(instructions_count, ReplayState),
> +        VMSTATE_UINT32(data_kind, ReplayState),
> +        VMSTATE_UINT32(has_unread_data, ReplayState),
> +        VMSTATE_UINT64(file_offset, ReplayState),
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
> +void replay_vmstate_register(void)
> +{
> +    vmstate_register(NULL, 0, &vmstate_replay, &replay_state);
> +}
>  
>  void replay_vmstate_init(void)
>  {
> diff --git a/vl.c b/vl.c
> index 6698d88..f2193cb 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4361,6 +4361,7 @@ int main(int argc, char **argv, char **envp)
>          configure_icount(icount_opts, &error_abort);
>          qemu_opts_del(icount_opts);
>      }
> +    replay_vmstate_register();
>  
>      if (default_net) {
>          QemuOptsList *net = qemu_find_opts("net");
> 
> 
>