Re: [Qemu-devel] [PATCH 1/7] spapr: Clean up DR entity sense handling

[Michael Roth]

Quoting David Gibson (2017-06-06 03:32:15)
> DRC classes have an entity_sense method to determine (in a specific PAPR
> sense) the presence or absence of a device plugged into a DRC.  However,
> we only have one implementation of the method, which explicitly tests for
> different DRC types.  This changes it to instead have different method
> implementations for the two cases: "logical" and "physical" DRCs.
> 
> While we're at it, the entity sense method always returns RTAS_OUT_SUCCESS,
> and the interesting value is returned via pass-by-reference.  Simplify this
> to directly return the value we care about
> 
> Signed-off-by: David Gibson <address@hidden>
> ---
>  hw/ppc/spapr_drc.c         | 76 
> ++++++++++++++++++++++++----------------------
>  hw/ppc/spapr_pci.c         |  6 ++--
>  hw/ppc/trace-events        |  1 -
>  include/hw/ppc/spapr_drc.h |  4 +--
>  4 files changed, 44 insertions(+), 43 deletions(-)
> 
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> index 39e7f30..da3779e 100644
> --- a/hw/ppc/spapr_drc.c
> +++ b/hw/ppc/spapr_drc.c
> @@ -185,39 +185,29 @@ static void set_signalled(sPAPRDRConnector *drc)
>   * based on the current allocation/indicator/power states
>   * for the DR connector.
>   */
> -static uint32_t entity_sense(sPAPRDRConnector *drc, sPAPRDREntitySense 
> *state)
> +static sPAPRDREntitySense physical_entity_sense(sPAPRDRConnector *drc)
>  {
> -    if (drc->dev) {
> -        if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI &&
> -            drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
> -            /* for logical DR, we return a state of UNUSABLE
> -             * iff the allocation state UNUSABLE.
> -             * Otherwise, report the state as USABLE/PRESENT,
> -             * as we would for PCI.
> -             */
> -            *state = SPAPR_DR_ENTITY_SENSE_UNUSABLE;
> -        } else {
> -            /* this assumes all PCI devices are assigned to
> -             * a 'live insertion' power domain, where QEMU
> -             * manages power state automatically as opposed
> -             * to the guest. present, non-PCI resources are
> -             * unaffected by power state.
> -             */
> -            *state = SPAPR_DR_ENTITY_SENSE_PRESENT;
> -        }
> +    /* this assumes all PCI devices are assigned to a 'live insertion'
> +     * power domain, where QEMU manages power state automatically as
> +     * opposed to the guest. present, non-PCI resources are unaffected
> +     * by power state.
> +     */
> +    return drc->dev ? SPAPR_DR_ENTITY_SENSE_PRESENT
> +        : SPAPR_DR_ENTITY_SENSE_EMPTY;
> +}
> +
> +static sPAPRDREntitySense logical_entity_sense(sPAPRDRConnector *drc)
> +{
> +    /* for logical DR, we return a state of UNUSABLE iff the
> +     * allocation state UNUSABLE.  Otherwise, report the state as
> +     * USABLE/PRESENT, as we would for PCI.
> +     */

Now that it's outside of the drc->dev block this comment isn't quite
accurate. And any rewordings I come up with in this new context
basically end up just describing the code (nice), so I think it should
just be dropped.

Otherwise:

Reviewed-by: Michael Roth <address@hidden>

> +    if (drc->dev
> +        && (drc->allocation_state != SPAPR_DR_ALLOCATION_STATE_UNUSABLE)) {
> +        return SPAPR_DR_ENTITY_SENSE_PRESENT;
>      } else {
> -        if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_PCI) {
> -            /* PCI devices, and only PCI devices, use EMPTY
> -             * in cases where we'd otherwise use UNUSABLE
> -             */
> -            *state = SPAPR_DR_ENTITY_SENSE_EMPTY;
> -        } else {
> -            *state = SPAPR_DR_ENTITY_SENSE_UNUSABLE;
> -        }
> +        return SPAPR_DR_ENTITY_SENSE_UNUSABLE;
>      }
> -
> -    trace_spapr_drc_entity_sense(spapr_drc_index(drc), *state);
> -    return RTAS_OUT_SUCCESS;
>  }
> 
>  static void prop_get_index(Object *obj, Visitor *v, const char *name,
> @@ -445,7 +435,6 @@ static void reset(DeviceState *d)
>  {
>      sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(d);
>      sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> -    sPAPRDREntitySense state;
> 
>      trace_spapr_drc_reset(spapr_drc_index(drc));
> 
> @@ -477,8 +466,7 @@ static void reset(DeviceState *d)
>          }
>      }
> 
> -    drck->entity_sense(drc, &state);
> -    if (state == SPAPR_DR_ENTITY_SENSE_PRESENT) {
> +    if (drck->dr_entity_sense(drc) == SPAPR_DR_ENTITY_SENSE_PRESENT) {
>          drck->set_signalled(drc);
>      }
>  }
> @@ -488,8 +476,7 @@ static bool spapr_drc_needed(void *opaque)
>      sPAPRDRConnector *drc = (sPAPRDRConnector *)opaque;
>      sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
>      bool rc = false;
> -    sPAPRDREntitySense value;
> -    drck->entity_sense(drc, &value);
> +    sPAPRDREntitySense value = drck->dr_entity_sense(drc);
> 
>      /* If no dev is plugged in there is no need to migrate the DRC state */
>      if (value != SPAPR_DR_ENTITY_SENSE_PRESENT) {
> @@ -667,7 +654,6 @@ static void spapr_dr_connector_class_init(ObjectClass *k, 
> void *data)
>      drck->set_indicator_state = set_indicator_state;
>      drck->set_allocation_state = set_allocation_state;
>      drck->get_name = get_name;
> -    drck->entity_sense = entity_sense;
>      drck->attach = attach;
>      drck->detach = detach;
>      drck->release_pending = release_pending;
> @@ -678,6 +664,20 @@ static void spapr_dr_connector_class_init(ObjectClass 
> *k, void *data)
>      dk->user_creatable = false;
>  }
> 
> +static void spapr_drc_physical_class_init(ObjectClass *k, void *data)
> +{
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_CLASS(k);
> +
> +    drck->dr_entity_sense = physical_entity_sense;
> +}
> +
> +static void spapr_drc_logical_class_init(ObjectClass *k, void *data)
> +{
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_CLASS(k);
> +
> +    drck->dr_entity_sense = logical_entity_sense;
> +}
> +
>  static void spapr_drc_cpu_class_init(ObjectClass *k, void *data)
>  {
>      sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_CLASS(k);
> @@ -716,6 +716,7 @@ static const TypeInfo spapr_drc_physical_info = {
>      .name          = TYPE_SPAPR_DRC_PHYSICAL,
>      .parent        = TYPE_SPAPR_DR_CONNECTOR,
>      .instance_size = sizeof(sPAPRDRConnector),
> +    .class_init    = spapr_drc_physical_class_init,
>      .abstract      = true,
>  };
> 
> @@ -723,6 +724,7 @@ static const TypeInfo spapr_drc_logical_info = {
>      .name          = TYPE_SPAPR_DRC_LOGICAL,
>      .parent        = TYPE_SPAPR_DR_CONNECTOR,
>      .instance_size = sizeof(sPAPRDRConnector),
> +    .class_init    = spapr_drc_logical_class_init,
>      .abstract      = true,
>  };
> 
> @@ -1010,7 +1012,7 @@ static void rtas_get_sensor_state(PowerPCCPU *cpu, 
> sPAPRMachineState *spapr,
>          goto out;
>      }
>      drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> -    ret = drck->entity_sense(drc, &sensor_state);
> +    sensor_state = drck->dr_entity_sense(drc);
> 
>  out:
>      rtas_st(rets, 0, ret);
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 0c181bb..5cba8f9 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1481,7 +1481,7 @@ static void spapr_phb_hot_plug_child(HotplugHandler 
> *plug_handler,
>              func_drc = spapr_phb_get_pci_func_drc(phb, pci_bus_num(bus),
>                                                    PCI_DEVFN(slotnr, i));
>              func_drck = SPAPR_DR_CONNECTOR_GET_CLASS(func_drc);
> -            func_drck->entity_sense(func_drc, &state);
> +            state = func_drck->dr_entity_sense(func_drc);
> 
>              if (state == SPAPR_DR_ENTITY_SENSE_PRESENT) {
>                  spapr_hotplug_req_add_by_index(func_drc);
> @@ -1522,7 +1522,7 @@ static void spapr_phb_hot_unplug_child(HotplugHandler 
> *plug_handler,
>                  func_drc = spapr_phb_get_pci_func_drc(phb, pci_bus_num(bus),
>                                                        PCI_DEVFN(slotnr, i));
>                  func_drck = SPAPR_DR_CONNECTOR_GET_CLASS(func_drc);
> -                func_drck->entity_sense(func_drc, &state);
> +                state = func_drck->dr_entity_sense(func_drc);
>                  if (state == SPAPR_DR_ENTITY_SENSE_PRESENT
>                      && !func_drck->release_pending(func_drc)) {
>                      error_setg(errp,
> @@ -1548,7 +1548,7 @@ static void spapr_phb_hot_unplug_child(HotplugHandler 
> *plug_handler,
>                  func_drc = spapr_phb_get_pci_func_drc(phb, pci_bus_num(bus),
>                                                        PCI_DEVFN(slotnr, i));
>                  func_drck = SPAPR_DR_CONNECTOR_GET_CLASS(func_drc);
> -                func_drck->entity_sense(func_drc, &state);
> +                state = func_drck->dr_entity_sense(func_drc);
>                  if (state == SPAPR_DR_ENTITY_SENSE_PRESENT) {
>                      spapr_hotplug_req_remove_by_index(func_drc);
>                  }
> diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events
> index 43d265f..4979397 100644
> --- a/hw/ppc/trace-events
> +++ b/hw/ppc/trace-events
> @@ -44,7 +44,6 @@ spapr_drc_set_allocation_state(uint32_t index, int state) 
> "drc: 0x%"PRIx32", sta
>  spapr_drc_set_allocation_state_finalizing(uint32_t index) "drc: 0x%"PRIx32
>  spapr_drc_set_configured(uint32_t index) "drc: 0x%"PRIx32
>  spapr_drc_set_configured_skipping(uint32_t index) "drc: 0x%"PRIx32", 
> isolated device"
> -spapr_drc_entity_sense(uint32_t index, int state) "drc: 0x%"PRIx32", state: 
> 0x%x"
>  spapr_drc_attach(uint32_t index) "drc: 0x%"PRIx32
>  spapr_drc_detach(uint32_t index) "drc: 0x%"PRIx32
>  spapr_drc_awaiting_isolated(uint32_t index) "drc: 0x%"PRIx32
> diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h
> index c88e1be..f892b94 100644
> --- a/include/hw/ppc/spapr_drc.h
> +++ b/include/hw/ppc/spapr_drc.h
> @@ -214,6 +214,8 @@ typedef struct sPAPRDRConnectorClass {
>      sPAPRDRConnectorTypeShift typeshift;
>      const char *typename; /* used in device tree, PAPR 13.5.2.6 & C.6.1 */
> 
> +    sPAPRDREntitySense (*dr_entity_sense)(sPAPRDRConnector *drc);
> +
>      /* accessors for guest-visible (generally via RTAS) DR state */
>      uint32_t (*set_isolation_state)(sPAPRDRConnector *drc,
>                                      sPAPRDRIsolationState state);
> @@ -223,8 +225,6 @@ typedef struct sPAPRDRConnectorClass {
>                                       sPAPRDRAllocationState state);
>      const char *(*get_name)(sPAPRDRConnector *drc);
> 
> -    uint32_t (*entity_sense)(sPAPRDRConnector *drc, sPAPRDREntitySense 
> *state);
> -
>      /* QEMU interfaces for managing hotplug operations */
>      void (*attach)(sPAPRDRConnector *drc, DeviceState *d, void *fdt,
>                     int fdt_start_offset, bool coldplug, Error **errp);
> -- 
> 2.9.4
>