s390x/css: device support for s390-ccw passthrough

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.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-7-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

hw/s390x/Makefile.objs

@@ -14,3 +14,4 @@ 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

hw/s390x/s390-ccw.c

@@ -0,0 +1,141 @@
+/*
+ * s390 CCW Assignment Support
+ *
+ * Copyright 2017 IBM Corp
+ * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
+ *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
+ *            Pierre Morel <pmorel@linux.vnet.ibm.com>
+ *
+ * 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 "hw/s390x/s390-ccw.h"
+
+static void s390_ccw_get_dev_info(S390CCWDevice *cdev,
+                                  char *sysfsdev,
+                                  Error **errp)
+{
+    unsigned int cssid, ssid, devid;
+    char dev_path[PATH_MAX] = {0}, *tmp;
+
+    if (!sysfsdev) {
+        error_setg(errp, "No host device provided");
+        error_append_hint(errp,
+                          "Use -device vfio-ccw,sysfsdev=PATH_TO_DEVICE\n");
+        return;
+    }
+
+    if (!realpath(sysfsdev, dev_path)) {
+        error_setg_errno(errp, errno, "Host device '%s' not found", sysfsdev);
+        return;
+    }
+
+    cdev->mdevid = g_strdup(basename(dev_path));
+
+    tmp = basename(dirname(dev_path));
+    if (sscanf(tmp, "%2x.%1x.%4x", &cssid, &ssid, &devid) != 3) {
+        error_setg_errno(errp, errno, "Failed to read %s", tmp);
+        return;
+    }
+
+    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, &err);
+    if (err) {
+        goto out_err_propagate;
+    }
+
+    sch = css_create_sch(ccw_dev->devno, false, cbus->squash_mcss, &err);
+    if (!sch) {
+        goto out_mdevid_free;
+    }
+    sch->driver_data = cdev;
+
+    ccw_dev->sch = sch;
+    ret = css_sch_build_schib(sch, &cdev->hostid);
+    if (ret) {
+        error_setg_errno(&err, -ret, "%s: Failed to build initial schib",
+                         __func__);
+        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:
+    css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
+    ccw_dev->sch = NULL;
+    g_free(sch);
+out_mdevid_free:
+    g_free(cdev->mdevid);
+out_err_propagate:
+    error_propagate(errp, err);
+}
+
+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)

include/hw/s390x/s390-ccw.h

@@ -0,0 +1,38 @@
+/*
+ * s390 CCW Assignment Support
+ *
+ * Copyright 2017 IBM Corp.
+ * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
+ *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
+ *
+ * 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