Re: [Qemu-devel] [PATCH v3 4/6] Introduce condition to notifiy waiters of completed command

["Michael S. Tsirkin" <mst@redhat.com>]

Typo in subject.

On Tue, May 26, 2015 at 05:33:42PM -0400, Stefan Berger wrote:
> Introduce a lock and a condition to notify anyone waiting for the completion
> of the execution of a TPM command by the backend (thread). The backend
> uses the condition to signal anyone waiting for command completion.
> We need to place the condition in two locations: one is invoked by the
> backend thread, the other by the bottom half thread.
> We will use the signalling to wait for command completion before VM
> suspend.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> ---
>  hw/tpm/tpm_int.h |  3 +++
>  hw/tpm/tpm_tis.c | 14 ++++++++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/hw/tpm/tpm_int.h b/hw/tpm/tpm_int.h
> index 6b2c9c9..70be1ad 100644
> --- a/hw/tpm/tpm_int.h
> +++ b/hw/tpm/tpm_int.h
> @@ -30,6 +30,9 @@ struct TPMState {
>      char *backend;
>      TPMBackend *be_driver;
>      TPMVersion be_tpm_version;
> +
> +    QemuMutex state_lock;
> +    QemuCond cmd_complete;
>  };
>  
>  #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
> diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> index 1fb4e17..f278e1e 100644
> --- a/hw/tpm/tpm_tis.c
> +++ b/hw/tpm/tpm_tis.c
> @@ -367,6 +367,8 @@ static void tpm_tis_receive_bh(void *opaque)
>      TPMTISEmuState *tis = &s->s.tis;
>      uint8_t locty = s->locty_number;
>  
> +    qemu_mutex_lock(&s->state_lock);
> +
>      tpm_tis_sts_set(&tis->loc[locty],
>                      TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
>      tis->loc[locty].state = TPM_TIS_STATE_COMPLETION;
> @@ -383,6 +385,10 @@ static void tpm_tis_receive_bh(void *opaque)
>      tpm_tis_raise_irq(s, locty,
>                        TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
>  #endif
> +
> +    /* notify of completed command */
> +    qemu_cond_signal(&s->cmd_complete);
> +    qemu_mutex_unlock(&s->state_lock);
>  }
>  
>  /*
> @@ -402,6 +408,11 @@ static void tpm_tis_receive_cb(TPMState *s, uint8_t locty,
>          }
>      }
>  
> +    qemu_mutex_lock(&s->state_lock);
> +    /* notify of completed command */
> +    qemu_cond_signal(&s->cmd_complete);
> +    qemu_mutex_unlock(&s->state_lock);
> +
>      qemu_bh_schedule(tis->bh);
>  }
>  
> @@ -1097,6 +1108,9 @@ static void tpm_tis_initfn(Object *obj)
>      memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
>                            s, "tpm-tis-mmio",
>                            TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
> +
> +    qemu_mutex_init(&s->state_lock);
> +    qemu_cond_init(&s->cmd_complete);
>  }
>  
>  static void tpm_tis_class_init(ObjectClass *klass, void *data)
> -- 
> 1.9.3
>