[Spice-devel] [PATCH] server: add vdi_port write retry timer. RHBZ 616772

[Arnon Gilboa]

Alon Levy wrote:
> Retry vdi_port_write whenever a write to the sif (i.e. virtio-serial) fails
> because the ivq (vq from host to guest) is full. There is no existing timer
> based or callback based mechanism. RHBZ 616772 is a request for virtio-serial
> to support such a callback.
>
> Please Ack.
>
> ---
>  server/reds.c |   30 ++++++++++++++++++++++++++++++
>  1 files changed, 30 insertions(+), 0 deletions(-)
>
> diff --git a/server/reds.c b/server/reds.c
> index 97a47ae..55d7cd4 100644
> --- a/server/reds.c
> +++ b/server/reds.c
> @@ -106,6 +106,7 @@ static void openssl_init();
>  #define KEY_MODIFIERS_TTL (1000 * 2) /*2sec*/
>  #define MM_TIMER_GRANULARITY_MS (1000 / 30)
>  #define MM_TIME_DELTA 400 /*ms*/
> +#define VDI_PORT_WRITE_RETRY_TIMEOUT 100 /*ms*/
>  
>  // approximate max receive message size
>  #define RECIVE_BUF_SIZE \
> @@ -279,6 +280,8 @@ typedef struct RedsState {
>      SpiceTimer *mig_timer;
>      SpiceTimer *key_modifiers_timer;
>      SpiceTimer *mm_timer;
> +    SpiceTimer *vdi_port_write_timer;
> +    int vdi_port_write_timer_started;
>  
>      TicketAuthentication taTicket;
>      SSL_CTX *ctx;
> @@ -1127,6 +1130,24 @@ static void reds_send_tokens()
>      reds_push_pipe_item(item);
>  }
>  
> +static int write_to_vdi_port();
> +
> +static void vdi_port_write_timer_start()
> +{
> +    if (reds->vdi_port_write_timer_started) {
> +        return;
> +    }
> +    reds->vdi_port_write_timer_started = TRUE;
> +    core->timer_start(reds->vdi_port_write_timer,
> +                      VDI_PORT_WRITE_RETRY_TIMEOUT);
> +}
> +
> +static void vdi_port_write_retry()
> +{
> +    write_to_vdi_port();
> +    reds->vdi_port_write_timer_started = FALSE;
> +}
> +
>  static int write_to_vdi_port()
>  {
>      VDIPortState *state = &reds->agent_state;
> @@ -1159,6 +1180,10 @@ static int write_to_vdi_port()
>          }
>          buf->now += n;
>      }
> +    // Workaround for lack of proper sif write_possible callback (RHBZ 616772)
> +    if (ring_item != NULL) {
> +        vdi_port_write_timer_start();
> +    }
>      return total;
>  }
>  
> @@ -3617,6 +3642,11 @@ static void do_spice_init(SpiceCoreInterface *core_interface)
>      if (!(reds->key_modifiers_timer = core->timer_add(key_modifiers_sender, NULL))) {
>          red_error("key modifiers timer create failed");
>      }
> +    if (!(reds->vdi_port_write_timer = core->timer_add(vdi_port_write_retry, NULL)))
> +    {
> +        red_error("vdi port write timer create failed");
> +    }
> +    reds->vdi_port_write_timer_started = FALSE;
>  
>  #ifdef RED_STATISTICS
>      int shm_name_len = strlen(SPICE_STAT_SHM_NAME) + 20;
>   
ACK