Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 705 insertions, 0 deletions

diff --git a/qemu/hw/ppc/spapr_vio.c b/qemu/hw/ppc/spapr_vio.c
new file mode 100644
index 000000000..c51eb8e24
--- /dev/null
+++ b/qemu/hw/ppc/spapr_vio.c
@@ -0,0 +1,705 @@
+/*
+ * QEMU sPAPR VIO code
+ *
+ * Copyright (c) 2010 David Gibson, IBM Corporation <dwg@au1.ibm.com>
+ * Based on the s390 virtio bus code:
+ * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw/hw.h"
+#include "sysemu/sysemu.h"
+#include "hw/boards.h"
+#include "hw/loader.h"
+#include "elf.h"
+#include "hw/sysbus.h"
+#include "sysemu/kvm.h"
+#include "sysemu/device_tree.h"
+#include "kvm_ppc.h"
+
+#include "hw/ppc/spapr.h"
+#include "hw/ppc/spapr_vio.h"
+#include "hw/ppc/xics.h"
+
+#include <libfdt.h>
+
+/* #define DEBUG_SPAPR */
+
+#ifdef DEBUG_SPAPR
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+static Property spapr_vio_props[] = {
+    DEFINE_PROP_UINT32("irq", VIOsPAPRDevice, irq, 0), \
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static char *spapr_vio_get_dev_name(DeviceState *qdev)
+{
+    VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
+    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
+    char *name;
+
+    /* Device tree style name device@reg */
+    name = g_strdup_printf("%s@%x", pc->dt_name, dev->reg);
+
+    return name;
+}
+
+static void spapr_vio_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->get_dev_path = spapr_vio_get_dev_name;
+    k->get_fw_dev_path = spapr_vio_get_dev_name;
+}
+
+static const TypeInfo spapr_vio_bus_info = {
+    .name = TYPE_SPAPR_VIO_BUS,
+    .parent = TYPE_BUS,
+    .class_init = spapr_vio_bus_class_init,
+    .instance_size = sizeof(VIOsPAPRBus),
+};
+
+VIOsPAPRDevice *spapr_vio_find_by_reg(VIOsPAPRBus *bus, uint32_t reg)
+{
+    BusChild *kid;
+    VIOsPAPRDevice *dev = NULL;
+
+    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
+        dev = (VIOsPAPRDevice *)kid->child;
+        if (dev->reg == reg) {
+            return dev;
+        }
+    }
+
+    return NULL;
+}
+
+static int vio_make_devnode(VIOsPAPRDevice *dev,
+                            void *fdt)
+{
+    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
+    int vdevice_off, node_off, ret;
+    char *dt_name;
+
+    vdevice_off = fdt_path_offset(fdt, "/vdevice");
+    if (vdevice_off < 0) {
+        return vdevice_off;
+    }
+
+    dt_name = spapr_vio_get_dev_name(DEVICE(dev));
+    node_off = fdt_add_subnode(fdt, vdevice_off, dt_name);
+    g_free(dt_name);
+    if (node_off < 0) {
+        return node_off;
+    }
+
+    ret = fdt_setprop_cell(fdt, node_off, "reg", dev->reg);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (pc->dt_type) {
+        ret = fdt_setprop_string(fdt, node_off, "device_type",
+                                 pc->dt_type);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    if (pc->dt_compatible) {
+        ret = fdt_setprop_string(fdt, node_off, "compatible",
+                                 pc->dt_compatible);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    if (dev->irq) {
+        uint32_t ints_prop[] = {cpu_to_be32(dev->irq), 0};
+
+        ret = fdt_setprop(fdt, node_off, "interrupts", ints_prop,
+                          sizeof(ints_prop));
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    ret = spapr_tcet_dma_dt(fdt, node_off, "ibm,my-dma-window", dev->tcet);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (pc->devnode) {
+        ret = (pc->devnode)(dev, fdt, node_off);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    return node_off;
+}
+
+/*
+ * CRQ handling
+ */
+static target_ulong h_reg_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                              target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    target_ulong queue_addr = args[1];
+    target_ulong queue_len = args[2];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+
+    if (!dev) {
+        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
+        return H_PARAMETER;
+    }
+
+    /* We can't grok a queue size bigger than 256M for now */
+    if (queue_len < 0x1000 || queue_len > 0x10000000) {
+        hcall_dprintf("Queue size too small or too big (0x" TARGET_FMT_lx
+                      ")\n", queue_len);
+        return H_PARAMETER;
+    }
+
+    /* Check queue alignment */
+    if (queue_addr & 0xfff) {
+        hcall_dprintf("Queue not aligned (0x" TARGET_FMT_lx ")\n", queue_addr);
+        return H_PARAMETER;
+    }
+
+    /* Check if device supports CRQs */
+    if (!dev->crq.SendFunc) {
+        hcall_dprintf("Device does not support CRQ\n");
+        return H_NOT_FOUND;
+    }
+
+    /* Already a queue ? */
+    if (dev->crq.qsize) {
+        hcall_dprintf("CRQ already registered\n");
+        return H_RESOURCE;
+    }
+    dev->crq.qladdr = queue_addr;
+    dev->crq.qsize = queue_len;
+    dev->crq.qnext = 0;
+
+    DPRINTF("CRQ for dev 0x" TARGET_FMT_lx " registered at 0x"
+            TARGET_FMT_lx "/0x" TARGET_FMT_lx "\n",
+            reg, queue_addr, queue_len);
+    return H_SUCCESS;
+}
+
+static target_ulong free_crq(VIOsPAPRDevice *dev)
+{
+    dev->crq.qladdr = 0;
+    dev->crq.qsize = 0;
+    dev->crq.qnext = 0;
+
+    DPRINTF("CRQ for dev 0x%" PRIx32 " freed\n", dev->reg);
+
+    return H_SUCCESS;
+}
+
+static target_ulong h_free_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                               target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+
+    if (!dev) {
+        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
+        return H_PARAMETER;
+    }
+
+    return free_crq(dev);
+}
+
+static target_ulong h_send_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                               target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    target_ulong msg_hi = args[1];
+    target_ulong msg_lo = args[2];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+    uint64_t crq_mangle[2];
+
+    if (!dev) {
+        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
+        return H_PARAMETER;
+    }
+    crq_mangle[0] = cpu_to_be64(msg_hi);
+    crq_mangle[1] = cpu_to_be64(msg_lo);
+
+    if (dev->crq.SendFunc) {
+        return dev->crq.SendFunc(dev, (uint8_t *)crq_mangle);
+    }
+
+    return H_HARDWARE;
+}
+
+static target_ulong h_enable_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                                 target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+
+    if (!dev) {
+        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
+        return H_PARAMETER;
+    }
+
+    return 0;
+}
+
+/* Returns negative error, 0 success, or positive: queue full */
+int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
+{
+    int rc;
+    uint8_t byte;
+
+    if (!dev->crq.qsize) {
+        fprintf(stderr, "spapr_vio_send_creq on uninitialized queue\n");
+        return -1;
+    }
+
+    /* Maybe do a fast path for KVM just writing to the pages */
+    rc = spapr_vio_dma_read(dev, dev->crq.qladdr + dev->crq.qnext, &byte, 1);
+    if (rc) {
+        return rc;
+    }
+    if (byte != 0) {
+        return 1;
+    }
+
+    rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext + 8,
+                             &crq[8], 8);
+    if (rc) {
+        return rc;
+    }
+
+    kvmppc_eieio();
+
+    rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext, crq, 8);
+    if (rc) {
+        return rc;
+    }
+
+    dev->crq.qnext = (dev->crq.qnext + 16) % dev->crq.qsize;
+
+    if (dev->signal_state & 1) {
+        qemu_irq_pulse(spapr_vio_qirq(dev));
+    }
+
+    return 0;
+}
+
+/* "quiesce" handling */
+
+static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev)
+{
+    if (dev->tcet) {
+        device_reset(DEVICE(dev->tcet));
+    }
+    free_crq(dev);
+}
+
+void spapr_vio_set_bypass(VIOsPAPRDevice *dev, bool bypass)
+{
+    if (!dev->tcet) {
+        return;
+    }
+
+    memory_region_set_enabled(&dev->mrbypass, bypass);
+    memory_region_set_enabled(spapr_tce_get_iommu(dev->tcet), !bypass);
+
+    dev->tcet->bypass = bypass;
+}
+
+static void rtas_set_tce_bypass(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                                uint32_t token,
+                                uint32_t nargs, target_ulong args,
+                                uint32_t nret, target_ulong rets)
+{
+    VIOsPAPRBus *bus = spapr->vio_bus;
+    VIOsPAPRDevice *dev;
+    uint32_t unit, enable;
+
+    if (nargs != 2) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+    unit = rtas_ld(args, 0);
+    enable = rtas_ld(args, 1);
+    dev = spapr_vio_find_by_reg(bus, unit);
+    if (!dev) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    if (!dev->tcet) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    spapr_vio_set_bypass(dev, !!enable);
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+}
+
+static void rtas_quiesce(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                         uint32_t token,
+                         uint32_t nargs, target_ulong args,
+                         uint32_t nret, target_ulong rets)
+{
+    VIOsPAPRBus *bus = spapr->vio_bus;
+    BusChild *kid;
+    VIOsPAPRDevice *dev = NULL;
+
+    if (nargs != 0) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
+        dev = (VIOsPAPRDevice *)kid->child;
+        spapr_vio_quiesce_one(dev);
+    }
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+}
+
+static VIOsPAPRDevice *reg_conflict(VIOsPAPRDevice *dev)
+{
+    VIOsPAPRBus *bus = DO_UPCAST(VIOsPAPRBus, bus, dev->qdev.parent_bus);
+    BusChild *kid;
+    VIOsPAPRDevice *other;
+
+    /*
+     * Check for a device other than the given one which is already
+     * using the requested address. We have to open code this because
+     * the given dev might already be in the list.
+     */
+    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
+        other = VIO_SPAPR_DEVICE(kid->child);
+
+        if (other != dev && other->reg == dev->reg) {
+            return other;
+        }
+    }
+
+    return 0;
+}
+
+static void spapr_vio_busdev_reset(DeviceState *qdev)
+{
+    VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
+    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
+
+    /* Shut down the request queue and TCEs if necessary */
+    spapr_vio_quiesce_one(dev);
+
+    dev->signal_state = 0;
+
+    spapr_vio_set_bypass(dev, false);
+    if (pc->reset) {
+        pc->reset(dev);
+    }
+}
+
+static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp)
+{
+    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
+    VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
+    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
+    char *id;
+
+    if (dev->reg != -1) {
+        /*
+         * Explicitly assigned address, just verify that no-one else
+         * is using it.  other mechanism). We have to open code this
+         * rather than using spapr_vio_find_by_reg() because sdev
+         * itself is already in the list.
+         */
+        VIOsPAPRDevice *other = reg_conflict(dev);
+
+        if (other) {
+            error_setg(errp, "%s and %s devices conflict at address %#x",
+                       object_get_typename(OBJECT(qdev)),
+                       object_get_typename(OBJECT(&other->qdev)),
+                       dev->reg);
+            return;
+        }
+    } else {
+        /* Need to assign an address */
+        VIOsPAPRBus *bus = DO_UPCAST(VIOsPAPRBus, bus, dev->qdev.parent_bus);
+
+        do {
+            dev->reg = bus->next_reg++;
+        } while (reg_conflict(dev));
+    }
+
+    /* Don't overwrite ids assigned on the command line */
+    if (!dev->qdev.id) {
+        id = spapr_vio_get_dev_name(DEVICE(dev));
+        dev->qdev.id = id;
+    }
+
+    dev->irq = xics_alloc(spapr->icp, 0, dev->irq, false);
+    if (!dev->irq) {
+        error_setg(errp, "can't allocate IRQ");
+        return;
+    }
+
+    if (pc->rtce_window_size) {
+        uint32_t liobn = SPAPR_VIO_LIOBN(dev->reg);
+
+        memory_region_init(&dev->mrroot, OBJECT(dev), "iommu-spapr-root",
+                           ram_size);
+        memory_region_init_alias(&dev->mrbypass, OBJECT(dev),
+                                 "iommu-spapr-bypass", get_system_memory(),
+                                 0, ram_size);
+        memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass, 1);
+        address_space_init(&dev->as, &dev->mrroot, qdev->id);
+
+        dev->tcet = spapr_tce_new_table(qdev, liobn,
+                                        0,
+                                        SPAPR_TCE_PAGE_SHIFT,
+                                        pc->rtce_window_size >>
+                                        SPAPR_TCE_PAGE_SHIFT, false);
+        dev->tcet->vdev = dev;
+        memory_region_add_subregion_overlap(&dev->mrroot, 0,
+                                            spapr_tce_get_iommu(dev->tcet), 2);
+    }
+
+    pc->realize(dev, errp);
+}
+
+static target_ulong h_vio_signal(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                                 target_ulong opcode,
+                                 target_ulong *args)
+{
+    target_ulong reg = args[0];
+    target_ulong mode = args[1];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+    VIOsPAPRDeviceClass *pc;
+
+    if (!dev) {
+        return H_PARAMETER;
+    }
+
+    pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
+
+    if (mode & ~pc->signal_mask) {
+        return H_PARAMETER;
+    }
+
+    dev->signal_state = mode;
+
+    return H_SUCCESS;
+}
+
+VIOsPAPRBus *spapr_vio_bus_init(void)
+{
+    VIOsPAPRBus *bus;
+    BusState *qbus;
+    DeviceState *dev;
+
+    /* Create bridge device */
+    dev = qdev_create(NULL, "spapr-vio-bridge");
+    qdev_init_nofail(dev);
+
+    /* Create bus on bridge device */
+
+    qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio");
+    bus = DO_UPCAST(VIOsPAPRBus, bus, qbus);
+    bus->next_reg = 0x71000000;
+
+    /* hcall-vio */
+    spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
+
+    /* hcall-crq */
+    spapr_register_hypercall(H_REG_CRQ, h_reg_crq);
+    spapr_register_hypercall(H_FREE_CRQ, h_free_crq);
+    spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
+    spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
+
+    /* RTAS calls */
+    spapr_rtas_register(RTAS_IBM_SET_TCE_BYPASS, "ibm,set-tce-bypass",
+                        rtas_set_tce_bypass);
+    spapr_rtas_register(RTAS_QUIESCE, "quiesce", rtas_quiesce);
+
+    return bus;
+}
+
+/* Represents sPAPR hcall VIO devices */
+
+static int spapr_vio_bridge_init(SysBusDevice *dev)
+{
+    /* nothing */
+    return 0;
+}
+
+static void spapr_vio_bridge_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->fw_name = "vdevice";
+    k->init = spapr_vio_bridge_init;
+}
+
+static const TypeInfo spapr_vio_bridge_info = {
+    .name          = "spapr-vio-bridge",
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SysBusDevice),
+    .class_init    = spapr_vio_bridge_class_init,
+};
+
+const VMStateDescription vmstate_spapr_vio = {
+    .name = "spapr_vio",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        /* Sanity check */
+        VMSTATE_UINT32_EQUAL(reg, VIOsPAPRDevice),
+        VMSTATE_UINT32_EQUAL(irq, VIOsPAPRDevice),
+
+        /* General VIO device state */
+        VMSTATE_UINTTL(signal_state, VIOsPAPRDevice),
+        VMSTATE_UINT64(crq.qladdr, VIOsPAPRDevice),
+        VMSTATE_UINT32(crq.qsize, VIOsPAPRDevice),
+        VMSTATE_UINT32(crq.qnext, VIOsPAPRDevice),
+
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void vio_spapr_device_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *k = DEVICE_CLASS(klass);
+    k->realize = spapr_vio_busdev_realize;
+    k->reset = spapr_vio_busdev_reset;
+    k->bus_type = TYPE_SPAPR_VIO_BUS;
+    k->props = spapr_vio_props;
+}
+
+static const TypeInfo spapr_vio_type_info = {
+    .name = TYPE_VIO_SPAPR_DEVICE,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(VIOsPAPRDevice),
+    .abstract = true,
+    .class_size = sizeof(VIOsPAPRDeviceClass),
+    .class_init = vio_spapr_device_class_init,
+};
+
+static void spapr_vio_register_types(void)
+{
+    type_register_static(&spapr_vio_bus_info);
+    type_register_static(&spapr_vio_bridge_info);
+    type_register_static(&spapr_vio_type_info);
+}
+
+type_init(spapr_vio_register_types)
+
+static int compare_reg(const void *p1, const void *p2)
+{
+    VIOsPAPRDevice const *dev1, *dev2;
+
+    dev1 = (VIOsPAPRDevice *)*(DeviceState **)p1;
+    dev2 = (VIOsPAPRDevice *)*(DeviceState **)p2;
+
+    if (dev1->reg < dev2->reg) {
+        return -1;
+    }
+    if (dev1->reg == dev2->reg) {
+        return 0;
+    }
+
+    /* dev1->reg > dev2->reg */
+    return 1;
+}
+
+int spapr_populate_vdevice(VIOsPAPRBus *bus, void *fdt)
+{
+    DeviceState *qdev, **qdevs;
+    BusChild *kid;
+    int i, num, ret = 0;
+
+    /* Count qdevs on the bus list */
+    num = 0;
+    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
+        num++;
+    }
+
+    /* Copy out into an array of pointers */
+    qdevs = g_malloc(sizeof(qdev) * num);
+    num = 0;
+    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
+        qdevs[num++] = kid->child;
+    }
+
+    /* Sort the array */
+    qsort(qdevs, num, sizeof(qdev), compare_reg);
+
+    /* Hack alert. Give the devices to libfdt in reverse order, we happen
+     * to know that will mean they are in forward order in the tree. */
+    for (i = num - 1; i >= 0; i--) {
+        VIOsPAPRDevice *dev = (VIOsPAPRDevice *)(qdevs[i]);
+
+        ret = vio_make_devnode(dev, fdt);
+
+        if (ret < 0) {
+            goto out;
+        }
+    }
+
+    ret = 0;
+out:
+    g_free(qdevs);
+
+    return ret;
+}
+
+int spapr_populate_chosen_stdout(void *fdt, VIOsPAPRBus *bus)
+{
+    VIOsPAPRDevice *dev;
+    char *name, *path;
+    int ret, offset;
+
+    dev = spapr_vty_get_default(bus);
+    if (!dev)
+        return 0;
+
+    offset = fdt_path_offset(fdt, "/chosen");
+    if (offset < 0) {
+        return offset;
+    }
+
+    name = spapr_vio_get_dev_name(DEVICE(dev));
+    path = g_strdup_printf("/vdevice/%s", name);
+
+    ret = fdt_setprop_string(fdt, offset, "linux,stdout-path", path);
+
+    g_free(name);
+    g_free(path);
+
+    return ret;
+}