Re: [Qemu-devel] [RFC PATCH v12 16/21]

[Pavel Dovgaluk]

This patch is the reduced version of prior "bottom halves" patch.

Pavel Dovgalyuk


> -----Original Message-----
> From: Pavel Dovgalyuk [mailto:address@hidden
> Sent: Tuesday, May 05, 2015 1:19 PM
> To: address@hidden
> Cc: address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden
> Subject: [RFC PATCH v12 16/21]
> 
> 
> 
> Signed-off-by: Pavel Dovgalyuk <address@hidden>
> ---
>  async.c                  |   24 +++++++++++++++++++++++-
>  dma-helpers.c            |    4 +++-
>  hw/timer/arm_timer.c     |    2 +-
>  include/block/aio.h      |   18 ++++++++++++++++++
>  include/qemu/main-loop.h |    1 +
>  main-loop.c              |    5 +++++
>  replay/replay-events.c   |   16 ++++++++++++++++
>  replay/replay-internal.h |    1 +
>  replay/replay.h          |    2 ++
>  stubs/replay.c           |    4 ++++
>  10 files changed, 74 insertions(+), 3 deletions(-)
> 
> diff --git a/async.c b/async.c
> index bd975c9..d092aa2 100644
> --- a/async.c
> +++ b/async.c
> @@ -27,6 +27,7 @@
>  #include "block/thread-pool.h"
>  #include "qemu/main-loop.h"
>  #include "qemu/atomic.h"
> +#include "replay/replay.h"
> 
>  /***********************************************************/
>  /* bottom halves (can be seen as timers which expire ASAP) */
> @@ -39,6 +40,8 @@ struct QEMUBH {
>      bool scheduled;
>      bool idle;
>      bool deleted;
> +    bool replay;
> +    uint64_t id;
>  };
> 
>  QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
> @@ -56,6 +59,21 @@ QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void 
> *opaque)
>      return bh;
>  }
> 
> +QEMUBH *aio_bh_new_replay(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
> +                          uint64_t id)
> +{
> +    QEMUBH *bh = aio_bh_new(ctx, cb, opaque);
> +    bh->replay = true;
> +    bh->id = id;
> +    return bh;
> +}
> +
> +void aio_bh_call(void *opaque)
> +{
> +    QEMUBH *bh = (QEMUBH *)opaque;
> +    bh->cb(bh->opaque);
> +}
> +
>  /* Multiple occurrences of aio_bh_poll cannot be called concurrently */
>  int aio_bh_poll(AioContext *ctx)
>  {
> @@ -78,7 +96,11 @@ int aio_bh_poll(AioContext *ctx)
>              if (!bh->idle)
>                  ret = 1;
>              bh->idle = 0;
> -            bh->cb(bh->opaque);
> +            if (!bh->replay) {
> +                aio_bh_call(bh);
> +            } else {
> +                replay_add_bh_event(bh, bh->id);
> +            }
>          }
>      }
> 
> diff --git a/dma-helpers.c b/dma-helpers.c
> index 6918572..357d7e9 100644
> --- a/dma-helpers.c
> +++ b/dma-helpers.c
> @@ -13,6 +13,7 @@
>  #include "qemu/range.h"
>  #include "qemu/thread.h"
>  #include "qemu/main-loop.h"
> +#include "replay/replay.h"
> 
>  /* #define DEBUG_IOMMU */
> 
> @@ -96,7 +97,8 @@ static void continue_after_map_failure(void *opaque)
>  {
>      DMAAIOCB *dbs = (DMAAIOCB *)opaque;
> 
> -    dbs->bh = qemu_bh_new(reschedule_dma, dbs);
> +    dbs->bh = qemu_bh_new_replay(reschedule_dma, dbs,
> +                                 replay_get_current_step());
>      qemu_bh_schedule(dbs->bh);
>  }
> 
> diff --git a/hw/timer/arm_timer.c b/hw/timer/arm_timer.c
> index 1452910..97784a0 100644
> --- a/hw/timer/arm_timer.c
> +++ b/hw/timer/arm_timer.c
> @@ -168,7 +168,7 @@ static arm_timer_state *arm_timer_init(uint32_t freq)
>      s->freq = freq;
>      s->control = TIMER_CTRL_IE;
> 
> -    bh = qemu_bh_new(arm_timer_tick, s);
> +    bh = qemu_bh_new_replay(arm_timer_tick, s, 0);
>      s->timer = ptimer_init(bh);
>      vmstate_register(NULL, -1, &vmstate_arm_timer, s);
>      return s;
> diff --git a/include/block/aio.h b/include/block/aio.h
> index 82cdf78..ed76b43 100644
> --- a/include/block/aio.h
> +++ b/include/block/aio.h
> @@ -35,6 +35,8 @@ struct BlockAIOCB {
>      const AIOCBInfo *aiocb_info;
>      BlockDriverState *bs;
>      BlockCompletionFunc *cb;
> +    bool replay;
> +    uint64_t replay_step;
>      void *opaque;
>      int refcnt;
>  };
> @@ -144,6 +146,17 @@ void aio_context_release(AioContext *ctx);
>  QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
> 
>  /**
> + * aio_bh_new_replay: Allocate a new bottom half structure for replay.
> + *
> + * This function calls aio_bh_new function and also fills replay parameters
> + * of the BH structure. BH created with this function in record/replay mode
> + * are executed through the replay queue only at checkpoints and instructions
> + * executions.
> + */
> +QEMUBH *aio_bh_new_replay(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
> +                          uint64_t id);
> +
> +/**
>   * aio_notify: Force processing of pending events.
>   *
>   * Similar to signaling a condition variable, aio_notify forces
> @@ -159,6 +172,11 @@ QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void 
> *opaque);
>  void aio_notify(AioContext *ctx);
> 
>  /**
> + * aio_bh_call: Executes callback function of the specified BH.
> + */
> +void aio_bh_call(void *opaque);
> +
> +/**
>   * aio_bh_poll: Poll bottom halves for an AioContext.
>   *
>   * These are internal functions used by the QEMU main loop.
> diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
> index 62c68c0..f5a98fe 100644
> --- a/include/qemu/main-loop.h
> +++ b/include/qemu/main-loop.h
> @@ -306,6 +306,7 @@ void qemu_iohandler_fill(GArray *pollfds);
>  void qemu_iohandler_poll(GArray *pollfds, int rc);
> 
>  QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque);
> +QEMUBH *qemu_bh_new_replay(QEMUBHFunc *cb, void *opaque, uint64_t id);
>  void qemu_bh_schedule_idle(QEMUBH *bh);
> 
>  #endif
> diff --git a/main-loop.c b/main-loop.c
> index 06aad06..87ebad4 100644
> --- a/main-loop.c
> +++ b/main-loop.c
> @@ -514,3 +514,8 @@ QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
>  {
>      return aio_bh_new(qemu_aio_context, cb, opaque);
>  }
> +
> +QEMUBH *qemu_bh_new_replay(QEMUBHFunc *cb, void *opaque, uint64_t id)
> +{
> +    return aio_bh_new_replay(qemu_aio_context, cb, opaque, id);
> +}
> diff --git a/replay/replay-events.c b/replay/replay-events.c
> index 409c9ad..ec15683 100755
> --- a/replay/replay-events.c
> +++ b/replay/replay-events.c
> @@ -35,6 +35,9 @@ static bool events_enabled = false;
>  static void replay_run_event(Event *event)
>  {
>      switch (event->event_kind) {
> +    case REPLAY_ASYNC_EVENT_BH:
> +        aio_bh_call(event->opaque);
> +        break;
>      default:
>          error_report("Replay: invalid async event ID (%d) in the queue",
>                      event->event_kind);
> @@ -133,10 +136,18 @@ static void replay_save_event(Event *event, int 
> checkpoint)
> 
>          /* save event-specific data */
>          switch (event->event_kind) {
> +        case REPLAY_ASYNC_EVENT_BH:
> +            replay_put_qword(event->id);
> +            break;
>          }
>      }
>  }
> 
> +void replay_add_bh_event(void *bh, uint64_t id)
> +{
> +    replay_add_event_internal(REPLAY_ASYNC_EVENT_BH, bh, NULL, id);
> +}
> +
>  /* Called with replay mutex locked */
>  void replay_save_events(int checkpoint)
>  {
> @@ -168,6 +179,11 @@ static Event *replay_read_event(int checkpoint)
> 
>      /* Events that has not to be in the queue */
>      switch (read_event_kind) {
> +    case REPLAY_ASYNC_EVENT_BH:
> +        if (read_id == -1) {
> +            read_id = replay_get_qword();
> +        }
> +        break;
>      default:
>          error_report("Unknown ID %d of replay event", read_event_kind);
>          exit(1);
> diff --git a/replay/replay-internal.h b/replay/replay-internal.h
> index f758371..29722cf 100755
> --- a/replay/replay-internal.h
> +++ b/replay/replay-internal.h
> @@ -39,6 +39,7 @@ enum ReplayEvents {
>  /* Asynchronous events IDs */
> 
>  enum ReplayAsyncEventKind {
> +    REPLAY_ASYNC_EVENT_BH,
>      REPLAY_ASYNC_COUNT
>  };
> 
> diff --git a/replay/replay.h b/replay/replay.h
> index b6c4a8d..f83dc8e 100755
> --- a/replay/replay.h
> +++ b/replay/replay.h
> @@ -96,5 +96,7 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint);
>  void replay_disable_events(void);
>  /*! Returns true when saving events is enabled */
>  bool replay_events_enabled(void);
> +/*! Adds BH event to the queue */
> +void replay_add_bh_event(void *bh, uint64_t id);
> 
>  #endif
> diff --git a/stubs/replay.c b/stubs/replay.c
> index 1be3575..268f3e0 100755
> --- a/stubs/replay.c
> +++ b/stubs/replay.c
> @@ -21,3 +21,7 @@ int runstate_is_running(void)
>  {
>      return 0;
>  }
> +
> +void replay_add_bh_event(void *bh, uint64_t id)
> +{
> +}