[Qemu-devel] [PATCH v8 02/16] spapr_drc: initial implementation of sPAPRDRConnector device

[Michael Roth <mdroth@linux.vnet.ibm.com>]

This device emulates a firmware abstraction used by pSeries guests to
manage hotplug/dynamic-reconfiguration of host-bridges, PCI devices,
memory, and CPUs. It is conceptually similar to an SHPC device,
complete with LED indicators to identify individual slots to physical
physical users and indicate when it is safe to remove a device. In
some cases it is also used to manage virtualized resources, such a
memory, CPUs, and physical-host bridges, which in the case of pSeries
guests are virtualized resources where the physical components are
managed by the host.

Guests communicate with these DR Connectors using RTAS calls,
generally by addressing the unique DRC index associated with a
particular connector for a particular resource. For introspection
purposes we expose this state initially as QOM properties, and
in subsequent patches will introduce the RTAS calls that make use of
it. This constitutes to the 'guest' interface.

On the QEMU side we provide an attach/detach interface to associate
or cleanup a DeviceState with a particular sPAPRDRConnector in
response to hotplug/unplug, respectively. This constitutes the
'physical' interface to the DR Connector.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/Makefile.objs       |   2 +-
 hw/ppc/spapr_drc.c         | 587 +++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr_drc.h | 199 +++++++++++++++
 3 files changed, 787 insertions(+), 1 deletion(-)
 create mode 100644 hw/ppc/spapr_drc.c
 create mode 100644 include/hw/ppc/spapr_drc.h

diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
index 437955d..c8ab06e 100644
--- a/hw/ppc/Makefile.objs
+++ b/hw/ppc/Makefile.objs
@@ -3,7 +3,7 @@ obj-y += ppc.o ppc_booke.o
 # IBM pSeries (sPAPR)
 obj-$(CONFIG_PSERIES) += spapr.o spapr_vio.o spapr_events.o
 obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o
-obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o
+obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o spapr_drc.o
 ifeq ($(CONFIG_PCI)$(CONFIG_PSERIES)$(CONFIG_LINUX), yyy)
 obj-y += spapr_pci_vfio.o
 endif
diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
new file mode 100644
index 0000000..22b331a
--- /dev/null
+++ b/hw/ppc/spapr_drc.c
@@ -0,0 +1,587 @@
+/*
+ * QEMU SPAPR Dynamic Reconfiguration Connector Implementation
+ *
+ * Copyright IBM Corp. 2014
+ *
+ * Authors:
+ *  Michael Roth      <mdroth@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "hw/ppc/spapr_drc.h"
+#include "qom/object.h"
+#include "hw/qdev.h"
+#include "qapi/visitor.h"
+#include "qemu/error-report.h"
+
+/* #define DEBUG_SPAPR_DRC */
+
+#ifdef DEBUG_SPAPR_DRC
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
+#define DPRINTFN(fmt, ...) \
+    do { DPRINTF(fmt, ## __VA_ARGS__); fprintf(stderr, "\n"); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#define DPRINTFN(fmt, ...) \
+    do { } while (0)
+#endif
+
+#define DRC_CONTAINER_PATH "/dr-connector"
+#define DRC_INDEX_TYPE_SHIFT 28
+#define DRC_INDEX_ID_MASK (~(~0 << DRC_INDEX_TYPE_SHIFT))
+
+static sPAPRDRConnectorTypeShift get_type_shift(sPAPRDRConnectorType type)
+{
+    uint32_t shift = 0;
+
+    /* make sure this isn't SPAPR_DR_CONNECTOR_TYPE_ANY, or some
+     * other wonky value.
+     */
+    g_assert(is_power_of_2(type));
+
+    while (type != (1 << shift)) {
+        shift++;
+    }
+    return shift;
+}
+
+static uint32_t get_index(sPAPRDRConnector *drc)
+{
+    /* no set format for a drc index: it only needs to be globally
+     * unique. this is how we encode the DRC type on bare-metal
+     * however, so might as well do that here
+     */
+    return (get_type_shift(drc->type) << DRC_INDEX_TYPE_SHIFT) |
+            (drc->id & DRC_INDEX_ID_MASK);
+}
+
+static int set_isolation_state(sPAPRDRConnector *drc,
+                               sPAPRDRIsolationState state)
+{
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+
+    DPRINTFN("drc: %x, set_isolation_state: %x", get_index(drc), state);
+
+    drc->isolation_state = state;
+
+    if (drc->isolation_state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {
+        /* if we're awaiting release, but still in an unconfigured state,
+         * it's likely the guest is still in the process of configuring
+         * the device and is transitioning the devices to an ISOLATED
+         * state as a part of that process. so we only complete the
+         * removal when this transition happens for a device in a
+         * configured state, as suggested by the state diagram from
+         * PAPR+ 2.7, 13.4
+         */
+        if (drc->awaiting_release) {
+            if (drc->configured) {
+                DPRINTFN("finalizing device removal");
+                drck->detach(drc, DEVICE(drc->dev), drc->detach_cb,
+                             drc->detach_cb_opaque, NULL);
+            } else {
+                DPRINTFN("deferring device removal on unconfigured device\n");
+            }
+        }
+        drc->configured = false;
+    }
+
+    return 0;
+}
+
+static int set_indicator_state(sPAPRDRConnector *drc,
+                               sPAPRDRIndicatorState state)
+{
+    DPRINTFN("drc: %x, set_indicator_state: %x", get_index(drc), state);
+    drc->indicator_state = state;
+    return 0;
+}
+
+static int set_allocation_state(sPAPRDRConnector *drc,
+                                sPAPRDRAllocationState state)
+{
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+
+    DPRINTFN("drc: %x, set_allocation_state: %x", get_index(drc), state);
+
+    if (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI) {
+        drc->allocation_state = state;
+        if (drc->awaiting_release &&
+            drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
+            DPRINTFN("finalizing device removal");
+            drck->detach(drc, DEVICE(drc->dev), drc->detach_cb,
+                         drc->detach_cb_opaque, NULL);
+        }
+    }
+    return 0;
+}
+
+static uint32_t get_type(sPAPRDRConnector *drc)
+{
+    return drc->type;
+}
+
+static const char *get_name(sPAPRDRConnector *drc)
+{
+    return drc->name;
+}
+
+static const void *get_fdt(sPAPRDRConnector *drc, int *fdt_start_offset)
+{
+    if (fdt_start_offset) {
+        *fdt_start_offset = drc->fdt_start_offset;
+    }
+    return drc->fdt;
+}
+
+static void set_configured(sPAPRDRConnector *drc)
+{
+    DPRINTFN("drc: %x, set_configured", get_index(drc));
+
+    if (drc->isolation_state != SPAPR_DR_ISOLATION_STATE_UNISOLATED) {
+        /* guest should be not configuring an isolated device */
+        DPRINTFN("drc: %x, set_configured: skipping isolated device",
+                 get_index(drc));
+        return;
+    }
+    drc->configured = true;
+}
+
+/*
+ * dr-entity-sense sensor value
+ * returned via get-sensor-state RTAS calls
+ * as expected by state diagram in PAPR+ 2.7, 13.4
+ * based on the current allocation/indicator/power states
+ * for the DR connector.
+ */
+static sPAPRDREntitySense entity_sense(sPAPRDRConnector *drc)
+{
+    sPAPRDREntitySense state;
+
+    if (drc->dev) {
+        if (drc->type != 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;
+        }
+    } else {
+        if (drc->type == 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;
+        }
+    }
+
+    DPRINTFN("drc: %x, entity_sense: %x", get_index(drc), state);
+    return state;
+}
+
+static void prop_get_index(Object *obj, Visitor *v, void *opaque,
+                                  const char *name, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    uint32_t value = (uint32_t)drck->get_index(drc);
+    visit_type_uint32(v, &value, name, errp);
+}
+
+static void prop_get_type(Object *obj, Visitor *v, void *opaque,
+                          const char *name, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    uint32_t value = (uint32_t)drck->get_type(drc);
+    visit_type_uint32(v, &value, name, errp);
+}
+
+static char *prop_get_name(Object *obj, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    return g_strdup(drck->get_name(drc));
+}
+
+static void prop_get_entity_sense(Object *obj, Visitor *v, void *opaque,
+                                  const char *name, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    uint32_t value = (uint32_t)drck->entity_sense(drc);
+    visit_type_uint32(v, &value, name, errp);
+}
+
+static void prop_get_fdt(Object *obj, Visitor *v, void *opaque,
+                        const char *name, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
+    int fdt_offset_next, fdt_offset, fdt_depth;
+    void *fdt;
+
+    if (!drc->fdt) {
+        return;
+    }
+
+    fdt = drc->fdt;
+    fdt_offset = drc->fdt_start_offset;
+    fdt_depth = 0;
+
+    do {
+        const char *name = NULL;
+        const struct fdt_property *prop = NULL;
+        int prop_len = 0, name_len = 0;
+        uint32_t tag;
+
+        tag = fdt_next_tag(fdt, fdt_offset, &fdt_offset_next);
+        switch (tag) {
+        case FDT_BEGIN_NODE:
+            fdt_depth++;
+            name = fdt_get_name(fdt, fdt_offset, &name_len);
+            visit_start_struct(v, NULL, NULL, name, 0, NULL);
+            break;
+        case FDT_END_NODE:
+            /* shouldn't ever see an FDT_END_NODE before FDT_BEGIN_NODE */
+            g_assert(fdt_depth > 0);
+            visit_end_struct(v, NULL);
+            fdt_depth--;
+            break;
+        case FDT_PROP: {
+            int i;
+            prop = fdt_get_property_by_offset(fdt, fdt_offset, &prop_len);
+            name = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
+            visit_start_list(v, name, NULL);
+            for (i = 0; i < prop_len; i++) {
+                visit_type_uint8(v, (uint8_t *)&prop->data[i], NULL, NULL);
+
+            }
+            visit_end_list(v, NULL);
+            break;
+        }
+        default:
+            error_setg(&error_abort, "device FDT in unexpected state: %d", tag);
+        }
+        fdt_offset = fdt_offset_next;
+    } while (fdt_depth != 0);
+}
+
+static void attach(sPAPRDRConnector *drc, DeviceState *d, void *fdt,
+                   int fdt_start_offset, bool coldplug, Error **errp)
+{
+    DPRINTFN("drc: %x, attach", get_index(drc));
+
+    if (drc->isolation_state != SPAPR_DR_ISOLATION_STATE_ISOLATED) {
+        error_setg(errp, "an attached device is still awaiting release");
+        return;
+    }
+    if (drc->type == SPAPR_DR_CONNECTOR_TYPE_PCI) {
+        g_assert(drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_USABLE);
+    }
+    g_assert(fdt || coldplug);
+
+    /* NOTE: setting initial isolation state to UNISOLATED means we can't
+     * detach unless guest has a userspace/kernel that moves this state
+     * back to ISOLATED in response to an unplug event, or this is done
+     * manually by the admin prior. if we force things while the guest
+     * may be accessing the device, we can easily crash the guest, so we
+     * we defer completion of removal in such cases to the reset() hook.
+     */
+    if (drc->type == SPAPR_DR_CONNECTOR_TYPE_PCI) {
+        drc->isolation_state = SPAPR_DR_ISOLATION_STATE_UNISOLATED;
+    }
+    drc->indicator_state = SPAPR_DR_INDICATOR_STATE_ACTIVE;
+
+    drc->dev = d;
+    drc->fdt = fdt;
+    drc->fdt_start_offset = fdt_start_offset;
+    drc->configured = false;
+
+    object_property_add_link(OBJECT(drc), "device",
+                             object_get_typename(OBJECT(drc->dev)),
+                             (Object **)(&drc->dev),
+                             NULL, 0, NULL);
+}
+
+static void detach(sPAPRDRConnector *drc, DeviceState *d,
+                   spapr_drc_detach_cb *detach_cb,
+                   void *detach_cb_opaque, Error **errp)
+{
+    DPRINTFN("drc: %x, detach", get_index(drc));
+
+    drc->detach_cb = detach_cb;
+    drc->detach_cb_opaque = detach_cb_opaque;
+
+    if (drc->isolation_state != SPAPR_DR_ISOLATION_STATE_ISOLATED) {
+        DPRINTFN("awaiting transition to isolated state before removal");
+        drc->awaiting_release = true;
+        return;
+    }
+
+    if (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI &&
+        drc->allocation_state != SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
+        DPRINTFN("awaiting transition to unusable state before removal");
+        drc->awaiting_release = true;
+        return;
+    }
+
+    drc->indicator_state = SPAPR_DR_INDICATOR_STATE_INACTIVE;
+
+    if (drc->detach_cb) {
+        drc->detach_cb(drc->dev, drc->detach_cb_opaque);
+    }
+
+    drc->awaiting_release = false;
+    g_free(drc->fdt);
+    drc->fdt = NULL;
+    drc->fdt_start_offset = 0;
+    object_property_del(OBJECT(drc), "device", NULL);
+    drc->dev = NULL;
+    drc->detach_cb = NULL;
+    drc->detach_cb_opaque = NULL;
+}
+
+static bool release_pending(sPAPRDRConnector *drc)
+{
+    return drc->awaiting_release;
+}
+
+static void reset(DeviceState *d)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(d);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+
+    DPRINTFN("drc reset: %x", drck->get_index(drc));
+    /* immediately upon reset we can safely assume DRCs whose devices are pending
+     * removal can be safely removed, and that they will subsequently be left in
+     * an ISOLATED state. move the DRC to this state in these cases (which will in
+     * turn complete any pending device removals)
+     */
+    if (drc->awaiting_release) {
+        drck->set_isolation_state(drc, SPAPR_DR_ISOLATION_STATE_ISOLATED);
+        /* generally this should also finalize the removal, but if the device
+         * hasn't yet been configured we normally defer removal under the
+         * assumption that this transition is taking place as part of device
+         * configuration. so check if we're still waiting after this, and
+         * force removal if we are
+         */
+        if (drc->awaiting_release) {
+            drck->detach(drc, DEVICE(drc->dev), drc->detach_cb,
+                         drc->detach_cb_opaque, NULL);
+        }
+
+        /* non-PCI devices may be awaiting a transition to UNUSABLE */
+        if (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI &&
+            drc->awaiting_release) {
+            drck->set_allocation_state(drc, SPAPR_DR_ALLOCATION_STATE_UNUSABLE);
+        }
+    }
+}
+
+static void realize(DeviceState *d, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(d);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    Object *root_container;
+    char link_name[256];
+    gchar *child_name;
+    Error *err = NULL;
+
+    DPRINTFN("drc realize: %x", drck->get_index(drc));
+    /* NOTE: we do this as part of realize/unrealize due to the fact
+     * that the guest will communicate with the DRC via RTAS calls
+     * referencing the global DRC index. By unlinking the DRC
+     * from DRC_CONTAINER_PATH/<drc_index> we effectively make it
+     * inaccessible by the guest, since lookups rely on this path
+     * existing in the composition tree
+     */
+    root_container = container_get(object_get_root(), DRC_CONTAINER_PATH);
+    snprintf(link_name, sizeof(link_name), "%x", drck->get_index(drc));
+    child_name = object_get_canonical_path_component(OBJECT(drc));
+    DPRINTFN("drc child name: %s", child_name);
+    object_property_add_alias(root_container, link_name,
+                              drc->owner, child_name, &err);
+    if (err) {
+        error_report("%s", error_get_pretty(err));
+        error_free(err);
+        object_unref(OBJECT(drc));
+    }
+    DPRINTFN("drc realize complete");
+}
+
+static void unrealize(DeviceState *d, Error **errp)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(d);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    Object *root_container;
+    char name[256];
+    Error *err = NULL;
+
+    DPRINTFN("drc unrealize: %x", drck->get_index(drc));
+    root_container = container_get(object_get_root(), DRC_CONTAINER_PATH);
+    snprintf(name, sizeof(name), "%x", drck->get_index(drc));
+    object_property_del(root_container, name, &err);
+    if (err) {
+        error_report("%s", error_get_pretty(err));
+        error_free(err);
+        object_unref(OBJECT(drc));
+    }
+}
+
+sPAPRDRConnector *spapr_dr_connector_new(Object *owner,
+                                         sPAPRDRConnectorType type,
+                                         uint32_t id)
+{
+    sPAPRDRConnector *drc =
+        SPAPR_DR_CONNECTOR(object_new(TYPE_SPAPR_DR_CONNECTOR));
+
+    g_assert(type);
+
+    drc->type = type;
+    drc->id = id;
+    drc->owner = owner;
+    object_property_add_child(owner, "dr-connector[*]", OBJECT(drc), NULL);
+    object_property_set_bool(OBJECT(drc), true, "realized", NULL);
+
+    /* human-readable name for a DRC to encode into the DT
+     * description. this is mainly only used within a guest in place
+     * of the unique DRC index.
+     *
+     * in the case of VIO/PCI devices, it corresponds to a
+     * "location code" that maps a logical device/function (DRC index)
+     * to a physical (or virtual in the case of VIO) location in the
+     * system by chaining together the "location label" for each
+     * encapsulating component.
+     *
+     * since this is more to do with diagnosing physical hardware
+     * issues than guest compatibility, we choose location codes/DRC
+     * names that adhere to the documented format, but avoid encoding
+     * the entire topology information into the label/code, instead
+     * just using the location codes based on the labels for the
+     * endpoints (VIO/PCI adaptor connectors), which is basically
+     * just "C" followed by an integer ID.
+     *
+     * DRC names as documented by PAPR+ v2.7, 13.5.2.4
+     * location codes as documented by PAPR+ v2.7, 12.3.1.5
+     */
+    switch (drc->type) {
+    case SPAPR_DR_CONNECTOR_TYPE_CPU:
+        drc->name = g_strdup_printf("CPU %d", id);
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_PHB:
+        drc->name = g_strdup_printf("PHB %d", id);
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_VIO:
+    case SPAPR_DR_CONNECTOR_TYPE_PCI:
+        drc->name = g_strdup_printf("C%d", id);
+        break;
+    case SPAPR_DR_CONNECTOR_TYPE_LMB:
+        drc->name = g_strdup_printf("LMB %d", id);
+        break;
+    default:
+        g_assert(false);
+    }
+
+    /* PCI slot always start in a USABLE state, and stay there */
+    if (drc->type == SPAPR_DR_CONNECTOR_TYPE_PCI) {
+        drc->allocation_state = SPAPR_DR_ALLOCATION_STATE_USABLE;
+    }
+
+    return drc;
+}
+
+static void spapr_dr_connector_instance_init(Object *obj)
+{
+    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
+
+    object_property_add_uint32_ptr(obj, "isolation-state",
+                                   &drc->isolation_state, NULL);
+    object_property_add_uint32_ptr(obj, "indicator-state",
+                                   &drc->indicator_state, NULL);
+    object_property_add_uint32_ptr(obj, "allocation-state",
+                                   &drc->allocation_state, NULL);
+    object_property_add_uint32_ptr(obj, "id", &drc->id, NULL);
+    object_property_add(obj, "index", "uint32", prop_get_index,
+                        NULL, NULL, NULL, NULL);
+    object_property_add(obj, "connector_type", "uint32", prop_get_type,
+                        NULL, NULL, NULL, NULL);
+    object_property_add_str(obj, "name", prop_get_name, NULL, NULL);
+    object_property_add(obj, "entity-sense", "uint32", prop_get_entity_sense,
+                        NULL, NULL, NULL, NULL);
+    object_property_add(obj, "fdt", "struct", prop_get_fdt,
+                        NULL, NULL, NULL, NULL);
+}
+
+static void spapr_dr_connector_class_init(ObjectClass *k, void *data)
+{
+    DeviceClass *dk = DEVICE_CLASS(k);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_CLASS(k);
+
+    dk->reset = reset;
+    dk->realize = realize;
+    dk->unrealize = unrealize;
+    drck->set_isolation_state = set_isolation_state;
+    drck->set_indicator_state = set_indicator_state;
+    drck->set_allocation_state = set_allocation_state;
+    drck->get_index = get_index;
+    drck->get_type = get_type;
+    drck->get_name = get_name;
+    drck->get_fdt = get_fdt;
+    drck->set_configured = set_configured;
+    drck->entity_sense = entity_sense;
+    drck->attach = attach;
+    drck->detach = detach;
+    drck->release_pending = release_pending;
+}
+
+static const TypeInfo spapr_dr_connector_info = {
+    .name          = TYPE_SPAPR_DR_CONNECTOR,
+    .parent        = TYPE_DEVICE,
+    .instance_size = sizeof(sPAPRDRConnector),
+    .instance_init = spapr_dr_connector_instance_init,
+    .class_size    = sizeof(sPAPRDRConnectorClass),
+    .class_init    = spapr_dr_connector_class_init,
+};
+
+static void spapr_drc_register_types(void)
+{
+    type_register_static(&spapr_dr_connector_info);
+}
+
+type_init(spapr_drc_register_types)
+
+/* helper functions for external users */
+
+sPAPRDRConnector *spapr_dr_connector_by_index(uint32_t index)
+{
+    Object *obj;
+    char name[256];
+
+    snprintf(name, sizeof(name), "%s/%x", DRC_CONTAINER_PATH, index);
+    obj = object_resolve_path(name, NULL);
+
+    return !obj ? NULL : SPAPR_DR_CONNECTOR(obj);
+}
+
+sPAPRDRConnector *spapr_dr_connector_by_id(sPAPRDRConnectorType type,
+                                           uint32_t id)
+{
+    return spapr_dr_connector_by_index(
+            (get_type_shift(type) << DRC_INDEX_TYPE_SHIFT) |
+            (id & DRC_INDEX_ID_MASK));
+}
diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h
new file mode 100644
index 0000000..34fdef9
--- /dev/null
+++ b/include/hw/ppc/spapr_drc.h
@@ -0,0 +1,199 @@
+/*
+ * QEMU SPAPR Dynamic Reconfiguration Connector Implementation
+ *
+ * Copyright IBM Corp. 2014
+ *
+ * Authors:
+ *  Michael Roth      <mdroth@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#if !defined(__HW_SPAPR_DRC_H__)
+#define __HW_SPAPR_DRC_H__
+
+#include "qom/object.h"
+#include "hw/qdev.h"
+#include "libfdt.h"
+
+#define TYPE_SPAPR_DR_CONNECTOR "spapr-dr-connector"
+#define SPAPR_DR_CONNECTOR_GET_CLASS(obj) \
+        OBJECT_GET_CLASS(sPAPRDRConnectorClass, obj, TYPE_SPAPR_DR_CONNECTOR)
+#define SPAPR_DR_CONNECTOR_CLASS(klass) \
+        OBJECT_CLASS_CHECK(sPAPRDRConnectorClass, klass, \
+                           TYPE_SPAPR_DR_CONNECTOR)
+#define SPAPR_DR_CONNECTOR(obj) OBJECT_CHECK(sPAPRDRConnector, (obj), \
+                                             TYPE_SPAPR_DR_CONNECTOR)
+
+/*
+ * Various hotplug types managed by sPAPRDRConnector
+ *
+ * these are somewhat arbitrary, but to make things easier
+ * when generating DRC indexes later we've aligned the bit
+ * positions with the values used to assign DRC indexes on
+ * pSeries. we use those values as bit shifts to allow for
+ * the OR'ing of these values in various QEMU routines, but
+ * for values exposed to the guest (via DRC indexes for
+ * instance) we will use the shift amounts.
+ */
+typedef enum {
+    SPAPR_DR_CONNECTOR_TYPE_SHIFT_CPU = 1,
+    SPAPR_DR_CONNECTOR_TYPE_SHIFT_PHB = 2,
+    SPAPR_DR_CONNECTOR_TYPE_SHIFT_VIO = 3,
+    SPAPR_DR_CONNECTOR_TYPE_SHIFT_PCI = 4,
+    SPAPR_DR_CONNECTOR_TYPE_SHIFT_LMB = 8,
+} sPAPRDRConnectorTypeShift;
+
+typedef enum {
+    SPAPR_DR_CONNECTOR_TYPE_ANY = ~0,
+    SPAPR_DR_CONNECTOR_TYPE_CPU = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_CPU,
+    SPAPR_DR_CONNECTOR_TYPE_PHB = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_PHB,
+    SPAPR_DR_CONNECTOR_TYPE_VIO = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_VIO,
+    SPAPR_DR_CONNECTOR_TYPE_PCI = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_PCI,
+    SPAPR_DR_CONNECTOR_TYPE_LMB = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_LMB,
+} sPAPRDRConnectorType;
+
+/*
+ * set via set-indicator RTAS calls
+ * as documented by PAPR+ 2.7 13.5.3.4, Table 177
+ *
+ * isolated: put device under firmware control
+ * unisolated: claim OS control of device (may or may not be in use)
+ */
+typedef enum {
+    SPAPR_DR_ISOLATION_STATE_ISOLATED   = 0,
+    SPAPR_DR_ISOLATION_STATE_UNISOLATED = 1
+} sPAPRDRIsolationState;
+
+/*
+ * set via set-indicator RTAS calls
+ * as documented by PAPR+ 2.7 13.5.3.4, Table 177
+ *
+ * unusable: mark device as unavailable to OS
+ * usable: mark device as available to OS
+ * exchange: (currently unused)
+ * recover: (currently unused)
+ */
+typedef enum {
+    SPAPR_DR_ALLOCATION_STATE_UNUSABLE  = 0,
+    SPAPR_DR_ALLOCATION_STATE_USABLE    = 1,
+    SPAPR_DR_ALLOCATION_STATE_EXCHANGE  = 2,
+    SPAPR_DR_ALLOCATION_STATE_RECOVER   = 3
+} sPAPRDRAllocationState;
+
+/*
+ * LED/visual indicator state
+ *
+ * set via set-indicator RTAS calls
+ * as documented by PAPR+ 2.7 13.5.3.4, Table 177,
+ * and PAPR+ 2.7 13.5.4.1, Table 180
+ *
+ * inactive: hotpluggable entity inactive and safely removable
+ * active: hotpluggable entity in use and not safely removable
+ * identify: (currently unused)
+ * action: (currently unused)
+ */
+typedef enum {
+    SPAPR_DR_INDICATOR_STATE_INACTIVE   = 0,
+    SPAPR_DR_INDICATOR_STATE_ACTIVE     = 1,
+    SPAPR_DR_INDICATOR_STATE_IDENTIFY   = 2,
+    SPAPR_DR_INDICATOR_STATE_ACTION     = 3,
+} sPAPRDRIndicatorState;
+
+/*
+ * returned via get-sensor-state RTAS calls
+ * as documented by PAPR+ 2.7 13.5.3.3, Table 175:
+ *
+ * empty: connector slot empty (e.g. empty hotpluggable PCI slot)
+ * present: connector slot populated and device available to OS
+ * unusable: device not currently available to OS
+ * exchange: (currently unused)
+ * recover: (currently unused)
+ */
+typedef enum {
+    SPAPR_DR_ENTITY_SENSE_EMPTY     = 0,
+    SPAPR_DR_ENTITY_SENSE_PRESENT   = 1,
+    SPAPR_DR_ENTITY_SENSE_UNUSABLE  = 2,
+    SPAPR_DR_ENTITY_SENSE_EXCHANGE  = 3,
+    SPAPR_DR_ENTITY_SENSE_RECOVER   = 4,
+} sPAPRDREntitySense;
+
+typedef enum {
+    SPAPR_DR_CC_RESPONSE_NEXT_SIB       = 1, /* currently unused */
+    SPAPR_DR_CC_RESPONSE_NEXT_CHILD     = 2,
+    SPAPR_DR_CC_RESPONSE_NEXT_PROPERTY  = 3,
+    SPAPR_DR_CC_RESPONSE_PREV_PARENT    = 4,
+    SPAPR_DR_CC_RESPONSE_SUCCESS        = 0,
+    SPAPR_DR_CC_RESPONSE_ERROR          = -1,
+    SPAPR_DR_CC_RESPONSE_CONTINUE       = -2,
+} sPAPRDRCCResponse;
+
+typedef void (spapr_drc_detach_cb)(DeviceState *d, void *opaque);
+
+typedef struct sPAPRDRConnector {
+    /*< private >*/
+    DeviceState parent;
+
+    sPAPRDRConnectorType type;
+    uint32_t id;
+    Object *owner;
+    const char *name;
+
+    /* sensor/indicator states */
+    uint32_t isolation_state;
+    uint32_t allocation_state;
+    uint32_t indicator_state;
+
+    /* configure-connector state */
+    void *fdt;
+    int fdt_start_offset;
+    bool configured;
+
+    bool awaiting_release;
+
+    /* device pointer, via link property */
+    DeviceState *dev;
+    spapr_drc_detach_cb *detach_cb;
+    void *detach_cb_opaque;
+} sPAPRDRConnector;
+
+typedef struct sPAPRDRConnectorClass {
+    /*< private >*/
+    DeviceClass parent;
+
+    /*< public >*/
+
+    /* accessors for guest-visible (generally via RTAS) DR state */
+    int (*set_isolation_state)(sPAPRDRConnector *drc,
+                               sPAPRDRIsolationState state);
+    int (*set_indicator_state)(sPAPRDRConnector *drc,
+                               sPAPRDRIndicatorState state);
+    int (*set_allocation_state)(sPAPRDRConnector *drc,
+                                sPAPRDRAllocationState state);
+    uint32_t (*get_index)(sPAPRDRConnector *drc);
+    uint32_t (*get_type)(sPAPRDRConnector *drc);
+    const char *(*get_name)(sPAPRDRConnector *drc);
+
+    sPAPRDREntitySense (*entity_sense)(sPAPRDRConnector *drc);
+
+    /* QEMU interfaces for managing FDT/configure-connector */
+    const void *(*get_fdt)(sPAPRDRConnector *drc, int *fdt_start_offset);
+    void (*set_configured)(sPAPRDRConnector *drc);
+
+    /* QEMU interfaces for managing hotplug operations */
+    void (*attach)(sPAPRDRConnector *drc, DeviceState *d, void *fdt,
+                   int fdt_start_offset, bool coldplug, Error **errp);
+    void (*detach)(sPAPRDRConnector *drc, DeviceState *d,
+                   spapr_drc_detach_cb *detach_cb,
+                   void *detach_cb_opaque, Error **errp);
+    bool (*release_pending)(sPAPRDRConnector *drc);
+} sPAPRDRConnectorClass;
+
+sPAPRDRConnector *spapr_dr_connector_new(Object *owner,
+                                         sPAPRDRConnectorType type,
+                                         uint32_t id);
+sPAPRDRConnector *spapr_dr_connector_by_index(uint32_t index);
+sPAPRDRConnector *spapr_dr_connector_by_id(sPAPRDRConnectorType type,
+                                           uint32_t id);
+
+#endif /* __HW_SPAPR_DRC_H__ */
-- 
1.9.1