Re: [qemu-s390x] [PATCH v9 4/6] s390x/ap: base Adjunct Processor (AP) object model

[Thomas Huth]

On 2018-09-27 00:54, Tony Krowiak wrote:
> From: Tony Krowiak <address@hidden>
> 
> Introduces the base object model for virtualizing AP devices.
> 
> Signed-off-by: Tony Krowiak <address@hidden>
> ---
[...]
> diff --git a/hw/s390x/ap-bridge.c b/hw/s390x/ap-bridge.c
> new file mode 100644
> index 000000000000..8564dfa96ee7
> --- /dev/null
> +++ b/hw/s390x/ap-bridge.c
> @@ -0,0 +1,81 @@
> +/*
> + * ap bridge
> + *
> + * Copyright 2018 IBM Corp.
> + * Author(s): Halil Pasic <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "hw/sysbus.h"
> +#include "qemu/bitops.h"
> +#include "hw/s390x/ap-bridge.h"
> +#include "cpu.h"
> +
> +static char *vfio_ap_bus_get_dev_path(DeviceState *dev)
> +{
> +    /* at most one */
> +    return g_strdup_printf("/1");
> +}
> +
> +static void vfio_ap_bus_class_init(ObjectClass *klass, void *data)
> +{
> +    BusClass *k = BUS_CLASS(klass);

I think calling the variable "oc" (or something similar) instead of
"klass" is prefered nowadays.

> +    k->get_dev_path = vfio_ap_bus_get_dev_path;
> +    /* More than one vfio-ap device does not make sense */
> +    k->max_dev = 1;

Would it make sense to set a DEVICE_CATEGORY here, too?

> +}
> +
> +static const TypeInfo vfio_ap_bus_info = {
> +    .name = TYPE_AP_BUS,
> +    .parent = TYPE_BUS,
> +    .instance_size = sizeof(APBus),
> +    .class_init = vfio_ap_bus_class_init,
> +};
> +
> +void s390_init_ap(void)
> +{
> +    DeviceState *dev;
> +
> +    /* If no AP instructions then no need for AP bridge */
> +    if (!s390_has_feat(S390_FEAT_AP)) {
> +        return;
> +    }
> +
> +    /* Create bridge device */
> +    dev = qdev_create(NULL, TYPE_AP_BRIDGE);
> +    object_property_add_child(qdev_get_machine(), TYPE_AP_BRIDGE,
> +                              OBJECT(dev), NULL);
> +    qdev_init_nofail(dev);
> +
> +    /* Create bus on bridge device */
> +    qbus_create(TYPE_AP_BUS, dev, TYPE_AP_BUS);
> + }
> +
> +
> +

One empty line should be enough?

> +static void ap_bridge_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
> +}
> +
> +static const TypeInfo ap_bridge_info = {
> +    .name          = TYPE_AP_BRIDGE,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(APBridge),
> +    .class_init    = ap_bridge_class_init,
> +};
> +
> +static void ap_register(void)
> +{
> +    type_register_static(&ap_bridge_info);
> +    type_register_static(&vfio_ap_bus_info);
> +}
> +
> +type_init(ap_register)
[...]
> diff --git a/include/hw/s390x/ap-bridge.h b/include/hw/s390x/ap-bridge.h
> new file mode 100644
> index 000000000000..b6ca6ae4ab17
> --- /dev/null
> +++ b/include/hw/s390x/ap-bridge.h
> @@ -0,0 +1,37 @@
> +/*
> + * ap bridge
> + *
> + * Copyright 2018 IBM Corp.
> + * Author(s): Halil Pasic <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +
> +#ifndef HW_S390X_AP_BRIDGE_H
> +#define HW_S390X_AP_BRIDGE_H
> +#include "qom/object.h"
> +#include "hw/qdev-core.h"
> +#include "hw/sysbus.h"
> +
> +typedef struct APBridge {
> +    SysBusDevice sysbus_dev;
> +    bool css_dev_path;

What is this css_dev_path variable good for? I don't see it used in any
of the other patches?
If you don't need it, I think you could get rid of this struct completely?

> +} APBridge;
> +
> +#define TYPE_AP_BRIDGE "ap-bridge"
> +#define AP_BRIDGE(obj) \
> +    OBJECT_CHECK(APBridge, (obj), TYPE_AP_BRIDGE)
> +
> +typedef struct APBus {
> +    BusState parent_obj;
> +} APBus;
> +
> +#define TYPE_AP_BUS "ap-bus"
> +#define AP_BUS(obj) \
> +     OBJECT_CHECK(APBus, (obj), TYPE_AP_BUS)

I think you could also get rid of AP_BRIDGE(), AP_BUS() and maybe even
struct APBus.

> +void s390_init_ap(void);
> +
> +#endif
> diff --git a/include/hw/s390x/ap-device.h b/include/hw/s390x/ap-device.h
> new file mode 100644
> index 000000000000..693df90cc041
> --- /dev/null
> +++ b/include/hw/s390x/ap-device.h
> @@ -0,0 +1,38 @@
> +/*
> + * Adjunct Processor (AP) matrix device interfaces
> + *
> + * Copyright 2018 IBM Corp.
> + * Author(s): Tony Krowiak <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +#ifndef HW_S390X_AP_DEVICE_H
> +#define HW_S390X_AP_DEVICE_H
> +
> +#define AP_DEVICE_TYPE       "ap-device"
> +
> +typedef struct APDevice {
> +    DeviceState parent_obj;
> +} APDevice;
> +
> +typedef struct APDeviceClass {
> +    DeviceClass parent_class;
> +} APDeviceClass;
> +
> +static inline APDevice *to_ap_dev(DeviceState *dev)
> +{
> +    return container_of(dev, APDevice, parent_obj);
> +}
> +
> +#define AP_DEVICE(obj) \
> +    OBJECT_CHECK(APDevice, (obj), AP_DEVICE_TYPE)
> +
> +#define AP_DEVICE_GET_CLASS(obj) \
> +    OBJECT_GET_CLASS(APDeviceClass, (obj), AP_DEVICE_TYPE)
> +
> +#define AP_DEVICE_CLASS(klass) \
> +    OBJECT_CLASS_CHECK(APDeviceClass, (klass), AP_DEVICE_TYPE)

Do you really need any of these definitions except AP_DEVICE_TYPE ?

 Thomas