Re: [Qemu-devel] [PATCH v5 06/13] s390x/css: device support for s390-ccw passthrough

[Alex Williamson]

On Wed, 12 Apr 2017 07:21:08 +0200
Dong Jia Shi <address@hidden> wrote:

> In order to support subchannels pass-through, we introduce a s390
> subchannel device called "s390-ccw" to hold the real subchannel info.
> The s390-ccw devices inherit from the abstract CcwDevice which connect
> to the existing virtual-css-bus.
> 
> Signed-off-by: Dong Jia Shi <address@hidden>
> ---
>  hw/s390x/Makefile.objs |   1 +
>  hw/s390x/s390-ccw.c    | 134 
> +++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/s390x/s390-ccw.h    |  38 ++++++++++++++
>  3 files changed, 173 insertions(+)
>  create mode 100644 hw/s390x/s390-ccw.c
>  create mode 100644 hw/s390x/s390-ccw.h
> 
> diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> index 41ac4ec..72a3d37 100644
> --- a/hw/s390x/Makefile.objs
> +++ b/hw/s390x/Makefile.objs
> @@ -13,3 +13,4 @@ obj-y += ccw-device.o
>  obj-y += s390-pci-bus.o s390-pci-inst.o
>  obj-y += s390-skeys.o
>  obj-$(CONFIG_KVM) += s390-skeys-kvm.o
> +obj-y += s390-ccw.o
> diff --git a/hw/s390x/s390-ccw.c b/hw/s390x/s390-ccw.c
> new file mode 100644
> index 0000000..f3d5ed1
> --- /dev/null
> +++ b/hw/s390x/s390-ccw.c
> @@ -0,0 +1,134 @@
> +/*
> + * s390 CCW Assignment Support
> + *
> + * Copyright 2017 IBM Corp
> + * Author(s): Dong Jia Shi <address@hidden>
> + *            Xiao Feng Ren <address@hidden>
> + *            Pierre Morel <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 "libgen.h"
> +#include "hw/s390x/css.h"
> +#include "hw/s390x/css-bridge.h"
> +#include "s390-ccw.h"
> +
> +static void s390_ccw_get_dev_info(S390CCWDevice *cdev,
> +                                  char *sysfsdev,
> +                                  Error **errp)
> +{
> +    char dev_path[PATH_MAX], *tmp;
> +    unsigned int cssid, ssid, devid;
> +
> +    if (!sysfsdev) {
> +        error_setg(errp, "No host device provided");
> +        error_append_hint(errp, "Use -vfio-ccw,sysfsdev=PATH_TO_DEVICE\n");

nit, the leading '-' here seems strange, either you're describing
'-device vfio-ccw,...', or only the 'vfio-ccw,...' part.  Maybe I
notice this because sometimes I do accidentally type -vfio-pci instead
of -device vfio-pci.  Thanks,

Alex

> +        return;
> +    }
> +
> +    if (!realpath(sysfsdev, dev_path)) {
> +        error_setg(errp, "Host device '%s' not found", sysfsdev);
> +        return;
> +    }
> +
> +    cdev->mdevid = g_strdup(basename(dev_path));
> +
> +    tmp = basename(dirname(dev_path));
> +    sscanf(tmp, "%2x.%1x.%4x", &cssid, &ssid, &devid);
> +
> +    cdev->hostid.cssid = cssid;
> +    cdev->hostid.ssid = ssid;
> +    cdev->hostid.devid = devid;
> +    cdev->hostid.valid = true;
> +}
> +
> +static void s390_ccw_realize(S390CCWDevice *cdev, char *sysfsdev, Error 
> **errp)
> +{
> +    CcwDevice *ccw_dev = CCW_DEVICE(cdev);
> +    CCWDeviceClass *ck = CCW_DEVICE_GET_CLASS(ccw_dev);
> +    DeviceState *parent = DEVICE(ccw_dev);
> +    BusState *qbus = qdev_get_parent_bus(parent);
> +    VirtualCssBus *cbus = VIRTUAL_CSS_BUS(qbus);
> +    SubchDev *sch;
> +    int ret;
> +    Error *err = NULL;
> +
> +    s390_ccw_get_dev_info(cdev, sysfsdev, errp);
> +    if (*errp) {
> +        return;
> +    }
> +
> +    sch = css_create_sch(ccw_dev->devno, false, cbus->squash_mcss, errp);
> +    if (!sch) {
> +        return;
> +    }
> +    sch->driver_data = cdev;
> +
> +    ccw_dev->sch = sch;
> +    ret = css_sch_build_schib(sch, &cdev->hostid);
> +    if (ret) {
> +        error_setg(&err, "%s: Failed to build initial schib: %d",
> +                   __func__, ret);
> +        goto out_err;
> +    }
> +
> +    ck->realize(ccw_dev, &err);
> +    if (err) {
> +        goto out_err;
> +    }
> +
> +    css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
> +                          parent->hotplugged, 1);
> +    return;
> +
> +out_err:
> +    error_propagate(errp, err);
> +    css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
> +    ccw_dev->sch = NULL;
> +    g_free(sch);
> +}
> +
> +static void s390_ccw_unrealize(S390CCWDevice *cdev, Error **errp)
> +{
> +    CcwDevice *ccw_dev = CCW_DEVICE(cdev);
> +    SubchDev *sch = ccw_dev->sch;
> +
> +    if (sch) {
> +        css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, 
> NULL);
> +        g_free(sch);
> +        ccw_dev->sch = NULL;
> +    }
> +
> +    g_free(cdev->mdevid);
> +}
> +
> +static void s390_ccw_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
> +
> +    dc->bus_type = TYPE_VIRTUAL_CSS_BUS;
> +    cdc->realize = s390_ccw_realize;
> +    cdc->unrealize = s390_ccw_unrealize;
> +}
> +
> +static const TypeInfo s390_ccw_info = {
> +    .name          = TYPE_S390_CCW,
> +    .parent        = TYPE_CCW_DEVICE,
> +    .instance_size = sizeof(S390CCWDevice),
> +    .class_size    = sizeof(S390CCWDeviceClass),
> +    .class_init    = s390_ccw_class_init,
> +    .abstract      = true,
> +};
> +
> +static void register_s390_ccw_type(void)
> +{
> +    type_register_static(&s390_ccw_info);
> +}
> +
> +type_init(register_s390_ccw_type)
> diff --git a/hw/s390x/s390-ccw.h b/hw/s390x/s390-ccw.h
> new file mode 100644
> index 0000000..b58d8e9
> --- /dev/null
> +++ b/hw/s390x/s390-ccw.h
> @@ -0,0 +1,38 @@
> +/*
> + * s390 CCW Assignment Support
> + *
> + * Copyright 2017 IBM Corp.
> + * Author(s): Dong Jia Shi <address@hidden>
> + *            Xiao Feng Ren <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_S390_CCW_H
> +#define HW_S390_CCW_H
> +
> +#include "hw/s390x/ccw-device.h"
> +
> +#define TYPE_S390_CCW "s390-ccw"
> +#define S390_CCW_DEVICE(obj) \
> +    OBJECT_CHECK(S390CCWDevice, (obj), TYPE_S390_CCW)
> +#define S390_CCW_DEVICE_CLASS(klass) \
> +    OBJECT_CLASS_CHECK(S390CCWDeviceClass, (klass), TYPE_S390_CCW)
> +#define S390_CCW_DEVICE_GET_CLASS(obj) \
> +    OBJECT_GET_CLASS(S390CCWDeviceClass, (obj), TYPE_S390_CCW)
> +
> +typedef struct S390CCWDevice {
> +    CcwDevice parent_obj;
> +    CssDevId hostid;
> +    char *mdevid;
> +} S390CCWDevice;
> +
> +typedef struct S390CCWDeviceClass {
> +    CCWDeviceClass parent_class;
> +    void (*realize)(S390CCWDevice *dev, char *sysfsdev, Error **errp);
> +    void (*unrealize)(S390CCWDevice *dev, Error **errp);
> +} S390CCWDeviceClass;
> +
> +#endif