Patchwork [8/8] s390: Add new channel I/O based virtio transport.

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Submitter Cornelia Huck
Date Dec. 7, 2012, 12:50 p.m.
Message ID <1354884626-15060-9-git-send-email-cornelia.huck@de.ibm.com>
Download mbox | patch
Permalink /patch/204478/
State New
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Comments

Cornelia Huck - Dec. 7, 2012, 12:50 p.m.
Add a new virtio transport that uses channel commands to perform
virtio operations.

Add a new machine type s390-ccw that uses this virtio-ccw transport
and make it the default machine for s390.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 hw/s390-virtio.c       | 149 ++++++--
 hw/s390x/Makefile.objs |   1 +
 hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
 hw/s390x/virtio-ccw.h  |  81 +++++
 trace-events           |   4 +
 5 files changed, 1124 insertions(+), 20 deletions(-)
 create mode 100644 hw/s390x/virtio-ccw.c
 create mode 100644 hw/s390x/virtio-ccw.h
Alexander Graf - Dec. 11, 2012, 10:53 a.m.
On 07.12.2012, at 13:50, Cornelia Huck wrote:

> Add a new virtio transport that uses channel commands to perform
> virtio operations.
> 
> Add a new machine type s390-ccw that uses this virtio-ccw transport
> and make it the default machine for s390.
> 
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
> hw/s390-virtio.c       | 149 ++++++--
> hw/s390x/Makefile.objs |   1 +
> hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
> hw/s390x/virtio-ccw.h  |  81 +++++
> trace-events           |   4 +
> 5 files changed, 1124 insertions(+), 20 deletions(-)
> create mode 100644 hw/s390x/virtio-ccw.c
> create mode 100644 hw/s390x/virtio-ccw.h
> 
> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
> index 9e1afb2..f29ff74 100644
> --- a/hw/s390-virtio.c
> +++ b/hw/s390-virtio.c
> @@ -33,6 +33,8 @@
> 
> #include "hw/s390-virtio-bus.h"
> #include "hw/s390x/sclp.h"
> +#include "hw/s390x/css.h"
> +#include "hw/s390x/virtio-ccw.h"
> 
> //#define DEBUG_S390
> 
> @@ -47,6 +49,7 @@
> #define KVM_S390_VIRTIO_NOTIFY          0
> #define KVM_S390_VIRTIO_RESET           1
> #define KVM_S390_VIRTIO_SET_STATUS      2
> +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
> 
> #define KERN_IMAGE_START                0x010000UL
> #define KERN_PARM_AREA                  0x010480UL
> @@ -63,6 +66,7 @@
> 
> static VirtIOS390Bus *s390_bus;
> static S390CPU **ipi_states;
> +VirtioCcwBus *ccw_bus;
> 
> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> {
> @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
> {
>     int r = 0, i;
> +    int cssid, ssid, schid, m;
> +    SubchDev *sch;
> 
>     dprintf("KVM hypercall: %ld\n", hypercall);
>     switch (hypercall) {
>     case KVM_S390_VIRTIO_NOTIFY:
>         if (mem > ram_size) {
> -            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> -                                                               mem, &i);
> -            if (dev) {
> -                virtio_queue_notify(dev->vdev, i);
> +            if (s390_bus) {
> +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> +                                                                   mem, &i);
> +                if (dev) {
> +                    virtio_queue_notify(dev->vdev, i);
> +                } else {
> +                    r = -EINVAL;
> +                }

We really want to factor out the DIAG handling code similar to how spapr handles its hypercalls. That way the legacy s390-virtio machine can register a VIRTIO_NOTIFY hypercall that works for it here, while the s390-virtio-ccw machine doesn't.

>             } else {
>                 r = -EINVAL;
>             }
> @@ -93,28 +103,49 @@ int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
>         }
>         break;
>     case KVM_S390_VIRTIO_RESET:
> -    {
> -        VirtIOS390Device *dev;
> -
> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> -        virtio_reset(dev->vdev);
> -        stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> -        s390_virtio_device_sync(dev);
> -        s390_virtio_reset_idx(dev);
> +        if (s390_bus) {
> +            VirtIOS390Device *dev;
> +
> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +            virtio_reset(dev->vdev);
> +            stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> +            s390_virtio_device_sync(dev);
> +            s390_virtio_reset_idx(dev);
> +        } else {
> +            r = -EINVAL;
> +        }
>         break;
> -    }
>     case KVM_S390_VIRTIO_SET_STATUS:
> -    {
> -        VirtIOS390Device *dev;
> +        if (s390_bus) {
> +            VirtIOS390Device *dev;
> 
> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> -        if (dev) {
> -            s390_virtio_device_update_status(dev);
> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +            if (dev) {
> +                s390_virtio_device_update_status(dev);
> +            } else {
> +                r = -EINVAL;
> +            }
>         } else {
>             r = -EINVAL;
>         }
>         break;
> -    }
> +    case KVM_S390_VIRTIO_CCW_NOTIFY:
> +        if (ccw_bus) {
> +            if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid, &ssid,
> +                                             &schid)) {
> +                r = -EINVAL;
> +            } else {
> +                sch = css_find_subch(m, cssid, ssid, schid);
> +                if (sch && css_subch_visible(sch)) {
> +                    virtio_queue_notify(virtio_ccw_get_vdev(sch), env->regs[3]);
> +                } else {
> +                    r = -EINVAL;
> +                }
> +            }
> +         } else {
> +             r = -EINVAL;
> +         }
> +         break;
>     default:
>         r = -EINVAL;
>         break;
> @@ -370,7 +401,6 @@ static QEMUMachine s390_machine = {
>     .no_sdcard = 1,
>     .use_virtcon = 1,
>     .max_cpus = 255,
> -    .is_default = 1,
> };
> 
> static void s390_machine_init(void)
> @@ -379,3 +409,82 @@ static void s390_machine_init(void)
> }
> 
> machine_init(s390_machine_init);
> +
> +static void ccw_init(QEMUMachineInitArgs *args)

Do you think it'd be possible to move this into its own .c file?

> +{
> +    ram_addr_t my_ram_size = args->ram_size;
> +    ram_addr_t ram_size = args->ram_size;
> +    const char *cpu_model = args->cpu_model;
> +    const char *kernel_filename = args->kernel_filename;
> +    const char *kernel_cmdline = args->kernel_cmdline;
> +    const char *initrd_filename = args->initrd_filename;
> +    CPUS390XState *env = NULL;
> +    MemoryRegion *sysmem = get_system_memory();
> +    MemoryRegion *ram = g_new(MemoryRegion, 1);
> +    int shift = 0;
> +    uint8_t *storage_keys;
> +    int ret;
> +
> +    /* s390x ram size detection needs a 16bit multiplier + an increment. So
> +       guests > 64GB can be specified in 2MB steps etc. */
> +    while ((my_ram_size >> (20 + shift)) > 65535) {
> +        shift++;
> +    }
> +    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
> +
> +    /* lets propagate the changed ram size into the global variable. */
> +    ram_size = my_ram_size;
> +
> +    /* get a BUS */
> +    ccw_bus = virtio_ccw_bus_init();
> +    s390_sclp_init();
> +
> +    /* allocate RAM */
> +    memory_region_init_ram(ram, "s390.ram", my_ram_size);
> +    vmstate_register_ram_global(ram);
> +    memory_region_add_subregion(sysmem, 0, ram);
> +
> +    /* allocate storage keys */
> +    storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
> +
> +    /* init CPUs */
> +    env = s390_init_cpus(cpu_model, storage_keys);
> +
> +    kvm_s390_enable_css_support(env);
> +
> +    /*
> +     * Create virtual css and set it as default so that non mcss-e
> +     * enabled guests only see virtio devices.
> +     */
> +    ret = css_create_css_image(VIRTUAL_CSSID, true);
> +    assert(ret == 0);
> +
> +
> +    s390_set_up_kernel(env, kernel_filename, kernel_cmdline, initrd_filename);
> +
> +    /* Create VirtIO network adapters */
> +    s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
> +
> +}
> +
> +static QEMUMachine ccw_machine = {
> +    .name = "s390-ccw-virtio",
> +    .alias = "s390-ccw",
> +    .desc = "VirtIO-ccw based S390 machine",
> +    .init = ccw_init,
> +    .no_cdrom = 1,
> +    .no_floppy = 1,
> +    .no_serial = 1,
> +    .no_parallel = 1,
> +    .no_sdcard = 1,
> +    .use_virtcon = 1,
> +    .max_cpus = 255,
> +    .is_default = 1,
> +};
> +
> +static void ccw_machine_init(void)
> +{
> +    qemu_register_machine(&ccw_machine);
> +}
> +
> +machine_init(ccw_machine_init);
> diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> index 378b099..d408558 100644
> --- a/hw/s390x/Makefile.objs
> +++ b/hw/s390x/Makefile.objs
> @@ -5,3 +5,4 @@ obj-y += sclp.o
> obj-y += event-facility.o
> obj-y += sclpquiesce.o sclpconsole.o
> obj-y += css.o
> +obj-y += virtio-ccw.o
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> new file mode 100644
> index 0000000..b4624ab
> --- /dev/null
> +++ b/hw/s390x/virtio-ccw.c
> @@ -0,0 +1,909 @@
> +/*
> + * virtio ccw target implementation

Please extract this into a separate patch.

> + *
> + * Copyright 2012 IBM Corp.
> + * Author(s): Cornelia Huck <cornelia.huck@de.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 <hw/hw.h>
> +#include "block.h"
> +#include "blockdev.h"
> +#include "sysemu.h"
> +#include "net.h"
> +#include "monitor.h"
> +#include "qemu-thread.h"
> +#include "hw/virtio.h"
> +#include "hw/virtio-serial.h"
> +#include "hw/virtio-net.h"
> +#include "hw/sysbus.h"
> +#include "bitops.h"
> +
> +#include "ioinst.h"
> +#include "css.h"
> +#include "virtio-ccw.h"
> +#include "trace.h"
> +
> +static const TypeInfo virtio_ccw_bus_info = {
> +    .name = TYPE_VIRTIO_CCW_BUS,
> +    .parent = TYPE_BUS,
> +    .instance_size = sizeof(VirtioCcwBus),
> +};
> +
> +static const VirtIOBindings virtio_ccw_bindings;
> +
> +VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
> +{
> +    VirtIODevice *vdev = NULL;
> +
> +    if (sch->driver_data) {
> +        vdev = ((VirtioCcwData *)sch->driver_data)->vdev;
> +    }
> +    return vdev;
> +}
> +
> +static void virtio_ccw_reset_subchannels(void *opaque)
> +{
> +    VirtioCcwBus *bus = opaque;
> +    BusChild *kid;
> +    VirtioCcwData *data;
> +
> +    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
> +        data = (VirtioCcwData *)kid->child;
> +        virtio_reset(data->vdev);
> +        css_reset_sch(data->sch);
> +    }
> +    css_reset();
> +}
> +
> +VirtioCcwBus *virtio_ccw_bus_init(void)
> +{
> +    VirtioCcwBus *cbus;
> +    BusState *bus;
> +    DeviceState *dev;
> +
> +    /* Create bridge device */
> +    dev = qdev_create(NULL, "virtio-ccw-bridge");
> +    qdev_init_nofail(dev);
> +
> +    /* Create bus on bridge device */
> +    bus = qbus_create(TYPE_VIRTIO_CCW_BUS, dev, "virtio-ccw");
> +    cbus = DO_UPCAST(VirtioCcwBus, bus, bus);
> +
> +    /* Enable hotplugging */
> +    bus->allow_hotplug = 1;
> +
> +    qemu_register_reset(virtio_ccw_reset_subchannels, cbus);
> +    return cbus;
> +}
> +
> +/* Communication blocks used by several channel commands. */
> +typedef struct VqInfoBlock {
> +    uint64_t queue;
> +    uint32_t align;
> +    uint16_t index;
> +    uint16_t num;
> +} QEMU_PACKED VqInfoBlock;
> +
> +typedef struct VqConfigBlock {
> +    uint16_t index;
> +    uint16_t num_max;
> +} QEMU_PACKED VqConfigBlock;
> +
> +typedef struct VirtioFeatDesc {
> +    uint32_t features;
> +    uint8_t index;
> +} QEMU_PACKED VirtioFeatDesc;
> +
> +/* Specify where the virtqueues for the subchannel are in guest memory. */
> +static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t addr, uint32_t align,
> +                              uint16_t index, uint16_t num)
> +{
> +    VirtioCcwData *data = sch->driver_data;
> +
> +    if (index > VIRTIO_PCI_QUEUE_MAX) {
> +        return -EINVAL;
> +    }
> +
> +    /* Current code in virtio.c relies on 4K alignment. */
> +    if (addr && (align != 4096)) {
> +        return -EINVAL;
> +    }
> +
> +    if (!data) {
> +        return -EINVAL;
> +    }
> +
> +    virtio_queue_set_addr(data->vdev, index, addr);
> +    if (!addr) {
> +        virtio_queue_set_vector(data->vdev, index, 0);
> +    } else {
> +        /* Fail if we don't have a big enough queue. */
> +        /* TODO: Add interface to handle vring.num changing */
> +        if (virtio_queue_get_num(data->vdev, index) > num) {
> +            return -EINVAL;
> +        }
> +        virtio_queue_set_vector(data->vdev, index, index);
> +    }
> +    /* tell notify handler in case of config change */
> +    data->vdev->config_vector = VIRTIO_PCI_QUEUE_MAX;
> +    return 0;
> +}
> +
> +static int virtio_ccw_cb(SubchDev *sch, CCW1 *ccw)
> +{
> +    int ret;
> +    VqInfoBlock info;
> +    uint8_t status;
> +    VirtioFeatDesc features;
> +    void *config;
> +    hwaddr indicators;
> +    VqConfigBlock vq_config;
> +    VirtioCcwData *data = sch->driver_data;
> +    bool check_len;
> +    int len;
> +
> +    if (!ccw) {
> +        return -EIO;
> +    }
> +
> +    if (!data) {
> +        return -EINVAL;
> +    }
> +
> +    trace_virtio_ccw_interpret_ccw(sch->cssid, sch->ssid, sch->schid,
> +                                   ccw->cmd_code);
> +    check_len = !((ccw->flags & CCW_FLAG_SLI) && !(ccw->flags & CCW_FLAG_DC));
> +
> +    /* Look at the command. */
> +    switch (ccw->cmd_code) {
> +    case CCW_CMD_SET_VQ:
> +        if (check_len) {
> +            if (ccw->count != sizeof(info)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(info)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        if (!qemu_get_ram_ptr(ccw->cda)) {
> +            ret = -EFAULT;
> +        } else {
> +            info.queue = ldq_phys(ccw->cda);
> +            info.align = ldl_phys(ccw->cda + sizeof(info.queue));
> +            info.index = lduw_phys(ccw->cda + sizeof(info.queue)
> +                                   + sizeof(info.align));
> +            info.num = lduw_phys(ccw->cda + sizeof(info.queue)
> +                                 + sizeof(info.align)
> +                                 + sizeof(info.index));
> +            ret = virtio_ccw_set_vqs(sch, info.queue, info.align, info.index,
> +                                     info.num);
> +            sch->curr_status.scsw.count = 0;
> +        }
> +        break;
> +    case CCW_CMD_VDEV_RESET:
> +        virtio_reset(data->vdev);
> +        ret = 0;
> +        break;
> +    case CCW_CMD_READ_FEAT:
> +        if (check_len) {
> +            if (ccw->count != sizeof(features)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(features)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        if (!qemu_get_ram_ptr(ccw->cda)) {
> +            ret = -EFAULT;
> +        } else {
> +            features.index = ldub_phys(ccw->cda + sizeof(features.features));
> +            if (features.index < ARRAY_SIZE(data->host_features)) {
> +                features.features = data->host_features[features.index];
> +            } else {
> +                /* Return zeroes if the guest supports more feature bits. */
> +                features.features = 0;
> +            }
> +            stl_le_phys(ccw->cda, features.features);
> +            sch->curr_status.scsw.count = ccw->count - sizeof(features);
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_WRITE_FEAT:
> +        if (check_len) {
> +            if (ccw->count != sizeof(features)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(features)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        if (!qemu_get_ram_ptr(ccw->cda)) {
> +            ret = -EFAULT;
> +        } else {
> +            features.index = ldub_phys(ccw->cda + sizeof(features.features));
> +            features.features = ldl_le_phys(ccw->cda);
> +            if (features.index < ARRAY_SIZE(data->host_features)) {
> +                if (data->vdev->set_features) {
> +                    data->vdev->set_features(data->vdev, features.features);
> +                }
> +                data->vdev->guest_features = features.features;
> +            } else {
> +                /*
> +                 * If the guest supports more feature bits, assert that it
> +                 * passes us zeroes for those we don't support.
> +                 */
> +                if (features.features) {
> +                    fprintf(stderr, "Guest bug: features[%i]=%x (expected 0)\n",
> +                            features.index, features.features);
> +                    /* XXX: do a unit check here? */
> +                }
> +            }
> +            sch->curr_status.scsw.count = ccw->count - sizeof(features);
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_READ_CONF:
> +        if (check_len) {
> +            if (ccw->count > data->vdev->config_len) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        }
> +        len = MIN(ccw->count, data->vdev->config_len);
> +        if (!qemu_get_ram_ptr(ccw->cda)) {
> +            ret = -EFAULT;
> +        } else {
> +            data->vdev->get_config(data->vdev, data->vdev->config);
> +            cpu_physical_memory_write(ccw->cda, data->vdev->config, len);
> +            sch->curr_status.scsw.count = ccw->count - len;
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_WRITE_CONF:
> +        if (check_len) {
> +            if (ccw->count > data->vdev->config_len) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        }
> +        len = MIN(ccw->count, data->vdev->config_len);
> +        config = qemu_get_ram_ptr(ccw->cda);
> +        if (!config) {
> +            ret = -EFAULT;
> +        } else {
> +            memcpy(data->vdev->config, config, len);
> +            if (data->vdev->set_config) {
> +                data->vdev->set_config(data->vdev, data->vdev->config);
> +            }
> +            sch->curr_status.scsw.count = ccw->count - len;
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_WRITE_STATUS:
> +        if (check_len) {
> +            if (ccw->count != sizeof(status)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(status)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        if (!qemu_get_ram_ptr(ccw->cda)) {
> +            ret = -EFAULT;
> +        } else {
> +            status = ldub_phys(ccw->cda);
> +            virtio_set_status(data->vdev, status);
> +            sch->curr_status.scsw.count = ccw->count - sizeof(status);
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_SET_IND:
> +        if (check_len) {
> +            if (ccw->count != sizeof(indicators)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(indicators)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        indicators = ldq_phys(ccw->cda);
> +        if (!indicators) {
> +            ret = -EFAULT;
> +        } else {
> +            data->indicators = indicators;
> +            sch->curr_status.scsw.count = ccw->count - sizeof(indicators);
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_SET_CONF_IND:
> +        if (check_len) {
> +            if (ccw->count != sizeof(indicators)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(indicators)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        indicators = ldq_phys(ccw->cda);
> +        if (!indicators) {
> +            ret = -EFAULT;
> +        } else {
> +            data->indicators2 = indicators;
> +            sch->curr_status.scsw.count = ccw->count - sizeof(indicators);
> +            ret = 0;
> +        }
> +        break;
> +    case CCW_CMD_READ_VQ_CONF:
> +        if (check_len) {
> +            if (ccw->count != sizeof(vq_config)) {
> +                ret = -EINVAL;
> +                break;
> +            }
> +        } else if (ccw->count < sizeof(vq_config)) {
> +            /* Can't execute command. */
> +            ret = -EINVAL;
> +            break;
> +        }
> +        if (!qemu_get_ram_ptr(ccw->cda)) {
> +            ret = -EFAULT;
> +        } else {
> +            vq_config.index = lduw_phys(ccw->cda);
> +            vq_config.num_max = virtio_queue_get_num(data->vdev,
> +                                                     vq_config.index);
> +            stw_phys(ccw->cda + sizeof(vq_config.index), vq_config.num_max);
> +            sch->curr_status.scsw.count = ccw->count - sizeof(vq_config);
> +            ret = 0;
> +        }
> +        break;
> +    default:
> +        ret = -EOPNOTSUPP;
> +        break;
> +    }
> +    return ret;
> +}
> +
> +static int virtio_ccw_device_init(VirtioCcwData *dev, VirtIODevice *vdev)
> +{
> +    unsigned int cssid = 0;
> +    unsigned int ssid = 0;
> +    unsigned int schid;
> +    unsigned int devno;
> +    bool have_devno = false;
> +    bool found = false;
> +    SubchDev *sch;
> +    int ret;
> +    int num;
> +
> +    sch = g_malloc0(sizeof(SubchDev));

Any reason to not just make sch part of dev?

Alex
Christian Borntraeger - Dec. 11, 2012, 12:06 p.m.
On 11/12/12 11:53, Alexander Graf wrote:
> 
> On 07.12.2012, at 13:50, Cornelia Huck wrote:
> 
>> Add a new virtio transport that uses channel commands to perform
>> virtio operations.
>>
>> Add a new machine type s390-ccw that uses this virtio-ccw transport
>> and make it the default machine for s390.
>>
>> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>> ---
>> hw/s390-virtio.c       | 149 ++++++--
>> hw/s390x/Makefile.objs |   1 +
>> hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
>> hw/s390x/virtio-ccw.h  |  81 +++++
>> trace-events           |   4 +
>> 5 files changed, 1124 insertions(+), 20 deletions(-)
>> create mode 100644 hw/s390x/virtio-ccw.c
>> create mode 100644 hw/s390x/virtio-ccw.h
>>
>> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
>> index 9e1afb2..f29ff74 100644
>> --- a/hw/s390-virtio.c
>> +++ b/hw/s390-virtio.c
>> @@ -33,6 +33,8 @@
>>
>> #include "hw/s390-virtio-bus.h"
>> #include "hw/s390x/sclp.h"
>> +#include "hw/s390x/css.h"
>> +#include "hw/s390x/virtio-ccw.h"
>>
>> //#define DEBUG_S390
>>
>> @@ -47,6 +49,7 @@
>> #define KVM_S390_VIRTIO_NOTIFY          0
>> #define KVM_S390_VIRTIO_RESET           1
>> #define KVM_S390_VIRTIO_SET_STATUS      2
>> +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
>>
>> #define KERN_IMAGE_START                0x010000UL
>> #define KERN_PARM_AREA                  0x010480UL
>> @@ -63,6 +66,7 @@
>>
>> static VirtIOS390Bus *s390_bus;
>> static S390CPU **ipi_states;
>> +VirtioCcwBus *ccw_bus;
>>
>> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>> {
>> @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>> int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
>> {
>>     int r = 0, i;
>> +    int cssid, ssid, schid, m;
>> +    SubchDev *sch;
>>
>>     dprintf("KVM hypercall: %ld\n", hypercall);
>>     switch (hypercall) {
>>     case KVM_S390_VIRTIO_NOTIFY:
>>         if (mem > ram_size) {
>> -            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
>> -                                                               mem, &i);
>> -            if (dev) {
>> -                virtio_queue_notify(dev->vdev, i);
>> +            if (s390_bus) {
>> +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
>> +                                                                   mem, &i);
>> +                if (dev) {
>> +                    virtio_queue_notify(dev->vdev, i);
>> +                } else {
>> +                    r = -EINVAL;
>> +                }
> 
> We really want to factor out the DIAG handling code similar to how spapr handles its hypercalls. That way the legacy s390-virtio machine can register a VIRTIO_NOTIFY hypercall that works for it here, while the s390-virtio-ccw machine doesn't.
> 

Agreed, but this has nothing to do with virtio-ccw and should be part of a follow-up cleanup. no?

Christian
Cornelia Huck - Dec. 11, 2012, 1:03 p.m.
On Tue, 11 Dec 2012 11:53:18 +0100
Alexander Graf <agraf@suse.de> wrote:

> 
> On 07.12.2012, at 13:50, Cornelia Huck wrote:
> 
> > Add a new virtio transport that uses channel commands to perform
> > virtio operations.
> > 
> > Add a new machine type s390-ccw that uses this virtio-ccw transport
> > and make it the default machine for s390.
> > 
> > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> > ---
> > hw/s390-virtio.c       | 149 ++++++--
> > hw/s390x/Makefile.objs |   1 +
> > hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
> > hw/s390x/virtio-ccw.h  |  81 +++++
> > trace-events           |   4 +
> > 5 files changed, 1124 insertions(+), 20 deletions(-)
> > create mode 100644 hw/s390x/virtio-ccw.c
> > create mode 100644 hw/s390x/virtio-ccw.h
> > 
> > diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
> > index 9e1afb2..f29ff74 100644
> > --- a/hw/s390-virtio.c
> > +++ b/hw/s390-virtio.c
> > @@ -33,6 +33,8 @@
> > 
> > #include "hw/s390-virtio-bus.h"
> > #include "hw/s390x/sclp.h"
> > +#include "hw/s390x/css.h"
> > +#include "hw/s390x/virtio-ccw.h"
> > 
> > //#define DEBUG_S390
> > 
> > @@ -47,6 +49,7 @@
> > #define KVM_S390_VIRTIO_NOTIFY          0
> > #define KVM_S390_VIRTIO_RESET           1
> > #define KVM_S390_VIRTIO_SET_STATUS      2
> > +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
> > 
> > #define KERN_IMAGE_START                0x010000UL
> > #define KERN_PARM_AREA                  0x010480UL
> > @@ -63,6 +66,7 @@
> > 
> > static VirtIOS390Bus *s390_bus;
> > static S390CPU **ipi_states;
> > +VirtioCcwBus *ccw_bus;
> > 
> > S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> > {
> > @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> > int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
> > {
> >     int r = 0, i;
> > +    int cssid, ssid, schid, m;
> > +    SubchDev *sch;
> > 
> >     dprintf("KVM hypercall: %ld\n", hypercall);
> >     switch (hypercall) {
> >     case KVM_S390_VIRTIO_NOTIFY:
> >         if (mem > ram_size) {
> > -            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> > -                                                               mem, &i);
> > -            if (dev) {
> > -                virtio_queue_notify(dev->vdev, i);
> > +            if (s390_bus) {
> > +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> > +                                                                   mem, &i);
> > +                if (dev) {
> > +                    virtio_queue_notify(dev->vdev, i);
> > +                } else {
> > +                    r = -EINVAL;
> > +                }
> 
> We really want to factor out the DIAG handling code similar to how spapr handles its hypercalls. That way the legacy s390-virtio machine can register a VIRTIO_NOTIFY hypercall that works for it here, while the s390-virtio-ccw machine doesn't.
> 
> >             } else {
> >                 r = -EINVAL;
> >             }
> > @@ -93,28 +103,49 @@ int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
> >         }
> >         break;
> >     case KVM_S390_VIRTIO_RESET:
> > -    {
> > -        VirtIOS390Device *dev;
> > -
> > -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > -        virtio_reset(dev->vdev);
> > -        stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> > -        s390_virtio_device_sync(dev);
> > -        s390_virtio_reset_idx(dev);
> > +        if (s390_bus) {
> > +            VirtIOS390Device *dev;
> > +
> > +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > +            virtio_reset(dev->vdev);
> > +            stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> > +            s390_virtio_device_sync(dev);
> > +            s390_virtio_reset_idx(dev);
> > +        } else {
> > +            r = -EINVAL;
> > +        }
> >         break;
> > -    }
> >     case KVM_S390_VIRTIO_SET_STATUS:
> > -    {
> > -        VirtIOS390Device *dev;
> > +        if (s390_bus) {
> > +            VirtIOS390Device *dev;
> > 
> > -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > -        if (dev) {
> > -            s390_virtio_device_update_status(dev);
> > +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > +            if (dev) {
> > +                s390_virtio_device_update_status(dev);
> > +            } else {
> > +                r = -EINVAL;
> > +            }
> >         } else {
> >             r = -EINVAL;
> >         }
> >         break;
> > -    }
> > +    case KVM_S390_VIRTIO_CCW_NOTIFY:
> > +        if (ccw_bus) {
> > +            if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid, &ssid,
> > +                                             &schid)) {
> > +                r = -EINVAL;
> > +            } else {
> > +                sch = css_find_subch(m, cssid, ssid, schid);
> > +                if (sch && css_subch_visible(sch)) {
> > +                    virtio_queue_notify(virtio_ccw_get_vdev(sch), env->regs[3]);
> > +                } else {
> > +                    r = -EINVAL;
> > +                }
> > +            }
> > +         } else {
> > +             r = -EINVAL;
> > +         }
> > +         break;
> >     default:
> >         r = -EINVAL;
> >         break;
> > @@ -370,7 +401,6 @@ static QEMUMachine s390_machine = {
> >     .no_sdcard = 1,
> >     .use_virtcon = 1,
> >     .max_cpus = 255,
> > -    .is_default = 1,
> > };
> > 
> > static void s390_machine_init(void)
> > @@ -379,3 +409,82 @@ static void s390_machine_init(void)
> > }
> > 
> > machine_init(s390_machine_init);
> > +
> > +static void ccw_init(QEMUMachineInitArgs *args)
> 
> Do you think it'd be possible to move this into its own .c file?

Any particular reason why it should be moved? I saw this file as
'handle generic s390 virtio stuff'.

> 
> > +{
> > +    ram_addr_t my_ram_size = args->ram_size;
> > +    ram_addr_t ram_size = args->ram_size;
> > +    const char *cpu_model = args->cpu_model;
> > +    const char *kernel_filename = args->kernel_filename;
> > +    const char *kernel_cmdline = args->kernel_cmdline;
> > +    const char *initrd_filename = args->initrd_filename;
> > +    CPUS390XState *env = NULL;
> > +    MemoryRegion *sysmem = get_system_memory();
> > +    MemoryRegion *ram = g_new(MemoryRegion, 1);
> > +    int shift = 0;
> > +    uint8_t *storage_keys;
> > +    int ret;
> > +
> > +    /* s390x ram size detection needs a 16bit multiplier + an increment. So
> > +       guests > 64GB can be specified in 2MB steps etc. */
> > +    while ((my_ram_size >> (20 + shift)) > 65535) {
> > +        shift++;
> > +    }
> > +    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
> > +
> > +    /* lets propagate the changed ram size into the global variable. */
> > +    ram_size = my_ram_size;
> > +
> > +    /* get a BUS */
> > +    ccw_bus = virtio_ccw_bus_init();
> > +    s390_sclp_init();
> > +
> > +    /* allocate RAM */
> > +    memory_region_init_ram(ram, "s390.ram", my_ram_size);
> > +    vmstate_register_ram_global(ram);
> > +    memory_region_add_subregion(sysmem, 0, ram);
> > +
> > +    /* allocate storage keys */
> > +    storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
> > +
> > +    /* init CPUs */
> > +    env = s390_init_cpus(cpu_model, storage_keys);
> > +
> > +    kvm_s390_enable_css_support(env);
> > +
> > +    /*
> > +     * Create virtual css and set it as default so that non mcss-e
> > +     * enabled guests only see virtio devices.
> > +     */
> > +    ret = css_create_css_image(VIRTUAL_CSSID, true);
> > +    assert(ret == 0);
> > +
> > +
> > +    s390_set_up_kernel(env, kernel_filename, kernel_cmdline, initrd_filename);
> > +
> > +    /* Create VirtIO network adapters */
> > +    s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
> > +
> > +}
> > +
> > +static QEMUMachine ccw_machine = {
> > +    .name = "s390-ccw-virtio",
> > +    .alias = "s390-ccw",
> > +    .desc = "VirtIO-ccw based S390 machine",
> > +    .init = ccw_init,
> > +    .no_cdrom = 1,
> > +    .no_floppy = 1,
> > +    .no_serial = 1,
> > +    .no_parallel = 1,
> > +    .no_sdcard = 1,
> > +    .use_virtcon = 1,
> > +    .max_cpus = 255,
> > +    .is_default = 1,
> > +};
> > +
> > +static void ccw_machine_init(void)
> > +{
> > +    qemu_register_machine(&ccw_machine);
> > +}
> > +
> > +machine_init(ccw_machine_init);
> > diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> > index 378b099..d408558 100644
> > --- a/hw/s390x/Makefile.objs
> > +++ b/hw/s390x/Makefile.objs
> > @@ -5,3 +5,4 @@ obj-y += sclp.o
> > obj-y += event-facility.o
> > obj-y += sclpquiesce.o sclpconsole.o
> > obj-y += css.o
> > +obj-y += virtio-ccw.o
> > diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> > new file mode 100644
> > index 0000000..b4624ab
> > --- /dev/null
> > +++ b/hw/s390x/virtio-ccw.c
> > @@ -0,0 +1,909 @@
> > +/*
> > + * virtio ccw target implementation
> 
> Please extract this into a separate patch.

You mean first add the virtio-ccw backend and then introduce the new
machine?


> > +static int virtio_ccw_device_init(VirtioCcwData *dev, VirtIODevice *vdev)
> > +{
> > +    unsigned int cssid = 0;
> > +    unsigned int ssid = 0;
> > +    unsigned int schid;
> > +    unsigned int devno;
> > +    bool have_devno = false;
> > +    bool found = false;
> > +    SubchDev *sch;
> > +    int ret;
> > +    int num;
> > +
> > +    sch = g_malloc0(sizeof(SubchDev));
> 
> Any reason to not just make sch part of dev?

If anything, we'd probably want the virtio-ccw stuff extending the
generic subchannel stuff (so that we can have a basic subchannel
structure which might later be extended in a different way if we want
real device passthrough).

I'll try to implement it in such a way that it can be easily refactored
and extended.
Alexander Graf - Dec. 12, 2012, 12:38 a.m.
On 11.12.2012, at 13:06, Christian Borntraeger wrote:

> On 11/12/12 11:53, Alexander Graf wrote:
>> 
>> On 07.12.2012, at 13:50, Cornelia Huck wrote:
>> 
>>> Add a new virtio transport that uses channel commands to perform
>>> virtio operations.
>>> 
>>> Add a new machine type s390-ccw that uses this virtio-ccw transport
>>> and make it the default machine for s390.
>>> 
>>> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>>> ---
>>> hw/s390-virtio.c       | 149 ++++++--
>>> hw/s390x/Makefile.objs |   1 +
>>> hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
>>> hw/s390x/virtio-ccw.h  |  81 +++++
>>> trace-events           |   4 +
>>> 5 files changed, 1124 insertions(+), 20 deletions(-)
>>> create mode 100644 hw/s390x/virtio-ccw.c
>>> create mode 100644 hw/s390x/virtio-ccw.h
>>> 
>>> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
>>> index 9e1afb2..f29ff74 100644
>>> --- a/hw/s390-virtio.c
>>> +++ b/hw/s390-virtio.c
>>> @@ -33,6 +33,8 @@
>>> 
>>> #include "hw/s390-virtio-bus.h"
>>> #include "hw/s390x/sclp.h"
>>> +#include "hw/s390x/css.h"
>>> +#include "hw/s390x/virtio-ccw.h"
>>> 
>>> //#define DEBUG_S390
>>> 
>>> @@ -47,6 +49,7 @@
>>> #define KVM_S390_VIRTIO_NOTIFY          0
>>> #define KVM_S390_VIRTIO_RESET           1
>>> #define KVM_S390_VIRTIO_SET_STATUS      2
>>> +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
>>> 
>>> #define KERN_IMAGE_START                0x010000UL
>>> #define KERN_PARM_AREA                  0x010480UL
>>> @@ -63,6 +66,7 @@
>>> 
>>> static VirtIOS390Bus *s390_bus;
>>> static S390CPU **ipi_states;
>>> +VirtioCcwBus *ccw_bus;
>>> 
>>> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>>> {
>>> @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>>> int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
>>> {
>>>    int r = 0, i;
>>> +    int cssid, ssid, schid, m;
>>> +    SubchDev *sch;
>>> 
>>>    dprintf("KVM hypercall: %ld\n", hypercall);
>>>    switch (hypercall) {
>>>    case KVM_S390_VIRTIO_NOTIFY:
>>>        if (mem > ram_size) {
>>> -            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
>>> -                                                               mem, &i);
>>> -            if (dev) {
>>> -                virtio_queue_notify(dev->vdev, i);
>>> +            if (s390_bus) {
>>> +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
>>> +                                                                   mem, &i);
>>> +                if (dev) {
>>> +                    virtio_queue_notify(dev->vdev, i);
>>> +                } else {
>>> +                    r = -EINVAL;
>>> +                }
>> 
>> We really want to factor out the DIAG handling code similar to how spapr handles its hypercalls. That way the legacy s390-virtio machine can register a VIRTIO_NOTIFY hypercall that works for it here, while the s390-virtio-ccw machine doesn't.
>> 
> 
> Agreed, but this has nothing to do with virtio-ccw and should be part of a follow-up cleanup. no?

I think it'd make the virtio-ccw machine implementation easier to implement and easier to separate. I can cook up a patch that does this though if you say you don't have anyone to work on this atm.


Alex
Alexander Graf - Dec. 12, 2012, 12:39 a.m.
On 11.12.2012, at 14:03, Cornelia Huck wrote:

> On Tue, 11 Dec 2012 11:53:18 +0100
> Alexander Graf <agraf@suse.de> wrote:
> 
>> 
>> On 07.12.2012, at 13:50, Cornelia Huck wrote:
>> 
>>> Add a new virtio transport that uses channel commands to perform
>>> virtio operations.
>>> 
>>> Add a new machine type s390-ccw that uses this virtio-ccw transport
>>> and make it the default machine for s390.
>>> 
>>> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>>> ---
>>> hw/s390-virtio.c       | 149 ++++++--
>>> hw/s390x/Makefile.objs |   1 +
>>> hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
>>> hw/s390x/virtio-ccw.h  |  81 +++++
>>> trace-events           |   4 +
>>> 5 files changed, 1124 insertions(+), 20 deletions(-)
>>> create mode 100644 hw/s390x/virtio-ccw.c
>>> create mode 100644 hw/s390x/virtio-ccw.h
>>> 
>>> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
>>> index 9e1afb2..f29ff74 100644
>>> --- a/hw/s390-virtio.c
>>> +++ b/hw/s390-virtio.c
>>> @@ -33,6 +33,8 @@
>>> 
>>> #include "hw/s390-virtio-bus.h"
>>> #include "hw/s390x/sclp.h"
>>> +#include "hw/s390x/css.h"
>>> +#include "hw/s390x/virtio-ccw.h"
>>> 
>>> //#define DEBUG_S390
>>> 
>>> @@ -47,6 +49,7 @@
>>> #define KVM_S390_VIRTIO_NOTIFY          0
>>> #define KVM_S390_VIRTIO_RESET           1
>>> #define KVM_S390_VIRTIO_SET_STATUS      2
>>> +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
>>> 
>>> #define KERN_IMAGE_START                0x010000UL
>>> #define KERN_PARM_AREA                  0x010480UL
>>> @@ -63,6 +66,7 @@
>>> 
>>> static VirtIOS390Bus *s390_bus;
>>> static S390CPU **ipi_states;
>>> +VirtioCcwBus *ccw_bus;
>>> 
>>> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>>> {
>>> @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>>> int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
>>> {
>>>    int r = 0, i;
>>> +    int cssid, ssid, schid, m;
>>> +    SubchDev *sch;
>>> 
>>>    dprintf("KVM hypercall: %ld\n", hypercall);
>>>    switch (hypercall) {
>>>    case KVM_S390_VIRTIO_NOTIFY:
>>>        if (mem > ram_size) {
>>> -            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
>>> -                                                               mem, &i);
>>> -            if (dev) {
>>> -                virtio_queue_notify(dev->vdev, i);
>>> +            if (s390_bus) {
>>> +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
>>> +                                                                   mem, &i);
>>> +                if (dev) {
>>> +                    virtio_queue_notify(dev->vdev, i);
>>> +                } else {
>>> +                    r = -EINVAL;
>>> +                }
>> 
>> We really want to factor out the DIAG handling code similar to how spapr handles its hypercalls. That way the legacy s390-virtio machine can register a VIRTIO_NOTIFY hypercall that works for it here, while the s390-virtio-ccw machine doesn't.
>> 
>>>            } else {
>>>                r = -EINVAL;
>>>            }
>>> @@ -93,28 +103,49 @@ int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
>>>        }
>>>        break;
>>>    case KVM_S390_VIRTIO_RESET:
>>> -    {
>>> -        VirtIOS390Device *dev;
>>> -
>>> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
>>> -        virtio_reset(dev->vdev);
>>> -        stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
>>> -        s390_virtio_device_sync(dev);
>>> -        s390_virtio_reset_idx(dev);
>>> +        if (s390_bus) {
>>> +            VirtIOS390Device *dev;
>>> +
>>> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
>>> +            virtio_reset(dev->vdev);
>>> +            stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
>>> +            s390_virtio_device_sync(dev);
>>> +            s390_virtio_reset_idx(dev);
>>> +        } else {
>>> +            r = -EINVAL;
>>> +        }
>>>        break;
>>> -    }
>>>    case KVM_S390_VIRTIO_SET_STATUS:
>>> -    {
>>> -        VirtIOS390Device *dev;
>>> +        if (s390_bus) {
>>> +            VirtIOS390Device *dev;
>>> 
>>> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
>>> -        if (dev) {
>>> -            s390_virtio_device_update_status(dev);
>>> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
>>> +            if (dev) {
>>> +                s390_virtio_device_update_status(dev);
>>> +            } else {
>>> +                r = -EINVAL;
>>> +            }
>>>        } else {
>>>            r = -EINVAL;
>>>        }
>>>        break;
>>> -    }
>>> +    case KVM_S390_VIRTIO_CCW_NOTIFY:
>>> +        if (ccw_bus) {
>>> +            if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid, &ssid,
>>> +                                             &schid)) {
>>> +                r = -EINVAL;
>>> +            } else {
>>> +                sch = css_find_subch(m, cssid, ssid, schid);
>>> +                if (sch && css_subch_visible(sch)) {
>>> +                    virtio_queue_notify(virtio_ccw_get_vdev(sch), env->regs[3]);
>>> +                } else {
>>> +                    r = -EINVAL;
>>> +                }
>>> +            }
>>> +         } else {
>>> +             r = -EINVAL;
>>> +         }
>>> +         break;
>>>    default:
>>>        r = -EINVAL;
>>>        break;
>>> @@ -370,7 +401,6 @@ static QEMUMachine s390_machine = {
>>>    .no_sdcard = 1,
>>>    .use_virtcon = 1,
>>>    .max_cpus = 255,
>>> -    .is_default = 1,
>>> };
>>> 
>>> static void s390_machine_init(void)
>>> @@ -379,3 +409,82 @@ static void s390_machine_init(void)
>>> }
>>> 
>>> machine_init(s390_machine_init);
>>> +
>>> +static void ccw_init(QEMUMachineInitArgs *args)
>> 
>> Do you think it'd be possible to move this into its own .c file?
> 
> Any particular reason why it should be moved? I saw this file as
> 'handle generic s390 virtio stuff'.

This file is "the legacy s390 virtio machine" file. Anything virtio-ccw machine should be separate :).


>> 
>>> +{
>>> +    ram_addr_t my_ram_size = args->ram_size;
>>> +    ram_addr_t ram_size = args->ram_size;
>>> +    const char *cpu_model = args->cpu_model;
>>> +    const char *kernel_filename = args->kernel_filename;
>>> +    const char *kernel_cmdline = args->kernel_cmdline;
>>> +    const char *initrd_filename = args->initrd_filename;
>>> +    CPUS390XState *env = NULL;
>>> +    MemoryRegion *sysmem = get_system_memory();
>>> +    MemoryRegion *ram = g_new(MemoryRegion, 1);
>>> +    int shift = 0;
>>> +    uint8_t *storage_keys;
>>> +    int ret;
>>> +
>>> +    /* s390x ram size detection needs a 16bit multiplier + an increment. So
>>> +       guests > 64GB can be specified in 2MB steps etc. */
>>> +    while ((my_ram_size >> (20 + shift)) > 65535) {
>>> +        shift++;
>>> +    }
>>> +    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
>>> +
>>> +    /* lets propagate the changed ram size into the global variable. */
>>> +    ram_size = my_ram_size;
>>> +
>>> +    /* get a BUS */
>>> +    ccw_bus = virtio_ccw_bus_init();
>>> +    s390_sclp_init();
>>> +
>>> +    /* allocate RAM */
>>> +    memory_region_init_ram(ram, "s390.ram", my_ram_size);
>>> +    vmstate_register_ram_global(ram);
>>> +    memory_region_add_subregion(sysmem, 0, ram);
>>> +
>>> +    /* allocate storage keys */
>>> +    storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
>>> +
>>> +    /* init CPUs */
>>> +    env = s390_init_cpus(cpu_model, storage_keys);
>>> +
>>> +    kvm_s390_enable_css_support(env);
>>> +
>>> +    /*
>>> +     * Create virtual css and set it as default so that non mcss-e
>>> +     * enabled guests only see virtio devices.
>>> +     */
>>> +    ret = css_create_css_image(VIRTUAL_CSSID, true);
>>> +    assert(ret == 0);
>>> +
>>> +
>>> +    s390_set_up_kernel(env, kernel_filename, kernel_cmdline, initrd_filename);
>>> +
>>> +    /* Create VirtIO network adapters */
>>> +    s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
>>> +
>>> +}
>>> +
>>> +static QEMUMachine ccw_machine = {
>>> +    .name = "s390-ccw-virtio",
>>> +    .alias = "s390-ccw",
>>> +    .desc = "VirtIO-ccw based S390 machine",
>>> +    .init = ccw_init,
>>> +    .no_cdrom = 1,
>>> +    .no_floppy = 1,
>>> +    .no_serial = 1,
>>> +    .no_parallel = 1,
>>> +    .no_sdcard = 1,
>>> +    .use_virtcon = 1,
>>> +    .max_cpus = 255,
>>> +    .is_default = 1,
>>> +};
>>> +
>>> +static void ccw_machine_init(void)
>>> +{
>>> +    qemu_register_machine(&ccw_machine);
>>> +}
>>> +
>>> +machine_init(ccw_machine_init);
>>> diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
>>> index 378b099..d408558 100644
>>> --- a/hw/s390x/Makefile.objs
>>> +++ b/hw/s390x/Makefile.objs
>>> @@ -5,3 +5,4 @@ obj-y += sclp.o
>>> obj-y += event-facility.o
>>> obj-y += sclpquiesce.o sclpconsole.o
>>> obj-y += css.o
>>> +obj-y += virtio-ccw.o
>>> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
>>> new file mode 100644
>>> index 0000000..b4624ab
>>> --- /dev/null
>>> +++ b/hw/s390x/virtio-ccw.c
>>> @@ -0,0 +1,909 @@
>>> +/*
>>> + * virtio ccw target implementation
>> 
>> Please extract this into a separate patch.
> 
> You mean first add the virtio-ccw backend and then introduce the new
> machine?

Yes :).

> 
> 
>>> +static int virtio_ccw_device_init(VirtioCcwData *dev, VirtIODevice *vdev)
>>> +{
>>> +    unsigned int cssid = 0;
>>> +    unsigned int ssid = 0;
>>> +    unsigned int schid;
>>> +    unsigned int devno;
>>> +    bool have_devno = false;
>>> +    bool found = false;
>>> +    SubchDev *sch;
>>> +    int ret;
>>> +    int num;
>>> +
>>> +    sch = g_malloc0(sizeof(SubchDev));
>> 
>> Any reason to not just make sch part of dev?
> 
> If anything, we'd probably want the virtio-ccw stuff extending the
> generic subchannel stuff (so that we can have a basic subchannel
> structure which might later be extended in a different way if we want
> real device passthrough).
> 
> I'll try to implement it in such a way that it can be easily refactored
> and extended.

Ok :).


Alex
Alexander Graf - Jan. 16, 2013, 1:24 p.m.
On 07.12.2012, at 13:50, Cornelia Huck wrote:

> Add a new virtio transport that uses channel commands to perform
> virtio operations.
> 
> Add a new machine type s390-ccw that uses this virtio-ccw transport
> and make it the default machine for s390.
> 
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
> hw/s390-virtio.c       | 149 ++++++--
> hw/s390x/Makefile.objs |   1 +
> hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
> hw/s390x/virtio-ccw.h  |  81 +++++
> trace-events           |   4 +
> 5 files changed, 1124 insertions(+), 20 deletions(-)
> create mode 100644 hw/s390x/virtio-ccw.c
> create mode 100644 hw/s390x/virtio-ccw.h
> 
> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
> index 9e1afb2..f29ff74 100644
> --- a/hw/s390-virtio.c
> +++ b/hw/s390-virtio.c
> @@ -33,6 +33,8 @@
> 
> #include "hw/s390-virtio-bus.h"
> #include "hw/s390x/sclp.h"
> +#include "hw/s390x/css.h"
> +#include "hw/s390x/virtio-ccw.h"
> 
> //#define DEBUG_S390
> 
> @@ -47,6 +49,7 @@
> #define KVM_S390_VIRTIO_NOTIFY          0
> #define KVM_S390_VIRTIO_RESET           1
> #define KVM_S390_VIRTIO_SET_STATUS      2
> +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
> 
> #define KERN_IMAGE_START                0x010000UL
> #define KERN_PARM_AREA                  0x010480UL
> @@ -63,6 +66,7 @@
> 
> static VirtIOS390Bus *s390_bus;
> static S390CPU **ipi_states;
> +VirtioCcwBus *ccw_bus;
> 
> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> {
> @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
> {
>     int r = 0, i;
> +    int cssid, ssid, schid, m;
> +    SubchDev *sch;
> 
>     dprintf("KVM hypercall: %ld\n", hypercall);
>     switch (hypercall) {
>     case KVM_S390_VIRTIO_NOTIFY:
>         if (mem > ram_size) {
> -            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> -                                                               mem, &i);
> -            if (dev) {
> -                virtio_queue_notify(dev->vdev, i);
> +            if (s390_bus) {
> +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> +                                                                   mem, &i);
> +                if (dev) {
> +                    virtio_queue_notify(dev->vdev, i);
> +                } else {
> +                    r = -EINVAL;
> +                }
>             } else {
>                 r = -EINVAL;
>             }
> @@ -93,28 +103,49 @@ int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
>         }
>         break;
>     case KVM_S390_VIRTIO_RESET:
> -    {
> -        VirtIOS390Device *dev;
> -
> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> -        virtio_reset(dev->vdev);
> -        stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> -        s390_virtio_device_sync(dev);
> -        s390_virtio_reset_idx(dev);
> +        if (s390_bus) {
> +            VirtIOS390Device *dev;
> +
> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +            virtio_reset(dev->vdev);
> +            stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> +            s390_virtio_device_sync(dev);
> +            s390_virtio_reset_idx(dev);
> +        } else {
> +            r = -EINVAL;
> +        }
>         break;
> -    }
>     case KVM_S390_VIRTIO_SET_STATUS:
> -    {
> -        VirtIOS390Device *dev;
> +        if (s390_bus) {
> +            VirtIOS390Device *dev;
> 
> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> -        if (dev) {
> -            s390_virtio_device_update_status(dev);
> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +            if (dev) {
> +                s390_virtio_device_update_status(dev);
> +            } else {
> +                r = -EINVAL;
> +            }
>         } else {
>             r = -EINVAL;
>         }
>         break;
> -    }
> +    case KVM_S390_VIRTIO_CCW_NOTIFY:
> +        if (ccw_bus) {
> +            if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid, &ssid,
> +                                             &schid)) {
> +                r = -EINVAL;
> +            } else {
> +                sch = css_find_subch(m, cssid, ssid, schid);
> +                if (sch && css_subch_visible(sch)) {
> +                    virtio_queue_notify(virtio_ccw_get_vdev(sch), env->regs[3]);
> +                } else {
> +                    r = -EINVAL;
> +                }
> +            }
> +         } else {
> +             r = -EINVAL;
> +         }
> +         break;
>     default:
>         r = -EINVAL;
>         break;
> @@ -370,7 +401,6 @@ static QEMUMachine s390_machine = {
>     .no_sdcard = 1,
>     .use_virtcon = 1,
>     .max_cpus = 255,
> -    .is_default = 1,
> };
> 
> static void s390_machine_init(void)
> @@ -379,3 +409,82 @@ static void s390_machine_init(void)
> }
> 
> machine_init(s390_machine_init);
> +
> +static void ccw_init(QEMUMachineInitArgs *args)
> +{
> +    ram_addr_t my_ram_size = args->ram_size;
> +    ram_addr_t ram_size = args->ram_size;
> +    const char *cpu_model = args->cpu_model;
> +    const char *kernel_filename = args->kernel_filename;
> +    const char *kernel_cmdline = args->kernel_cmdline;
> +    const char *initrd_filename = args->initrd_filename;
> +    CPUS390XState *env = NULL;
> +    MemoryRegion *sysmem = get_system_memory();
> +    MemoryRegion *ram = g_new(MemoryRegion, 1);
> +    int shift = 0;
> +    uint8_t *storage_keys;
> +    int ret;
> +
> +    /* s390x ram size detection needs a 16bit multiplier + an increment. So
> +       guests > 64GB can be specified in 2MB steps etc. */
> +    while ((my_ram_size >> (20 + shift)) > 65535) {
> +        shift++;
> +    }
> +    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
> +
> +    /* lets propagate the changed ram size into the global variable. */
> +    ram_size = my_ram_size;
> +
> +    /* get a BUS */
> +    ccw_bus = virtio_ccw_bus_init();
> +    s390_sclp_init();
> +
> +    /* allocate RAM */
> +    memory_region_init_ram(ram, "s390.ram", my_ram_size);
> +    vmstate_register_ram_global(ram);
> +    memory_region_add_subregion(sysmem, 0, ram);
> +
> +    /* allocate storage keys */
> +    storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
> +
> +    /* init CPUs */
> +    env = s390_init_cpus(cpu_model, storage_keys);
> +
> +    kvm_s390_enable_css_support(env);
> +
> +    /*
> +     * Create virtual css and set it as default so that non mcss-e
> +     * enabled guests only see virtio devices.
> +     */
> +    ret = css_create_css_image(VIRTUAL_CSSID, true);
> +    assert(ret == 0);
> +
> +
> +    s390_set_up_kernel(env, kernel_filename, kernel_cmdline, initrd_filename);
> +
> +    /* Create VirtIO network adapters */
> +    s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
> +
> +}
> +
> +static QEMUMachine ccw_machine = {
> +    .name = "s390-ccw-virtio",
> +    .alias = "s390-ccw",
> +    .desc = "VirtIO-ccw based S390 machine",
> +    .init = ccw_init,
> +    .no_cdrom = 1,
> +    .no_floppy = 1,
> +    .no_serial = 1,
> +    .no_parallel = 1,
> +    .no_sdcard = 1,
> +    .use_virtcon = 1,

The ccw machine should use the ASCII console as default.


Alex
Richard Henderson - Jan. 16, 2013, 4:46 p.m.
$SUBJECT reminds me that the tcg s390x port is now prepared
to implement channel insns, but previously there were no
channels worth talking about:

> /* I/O Instructions.  For each we simply indicate non-operation.  */
>     C(0xb276, XSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb230, CSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb231, HSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb232, MSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb23b, RCHP,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb238, RSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb233, SSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb234, STSCH,   S,     Z,   0, 0, 0, 0, subchannel, 0)
>     C(0xb235, TSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)

With a bit of help, I can make these emulated insns implement
virtio as well.


r~
Alexander Graf - Jan. 16, 2013, 5:05 p.m.
On 16.01.2013, at 17:46, Richard Henderson wrote:

> $SUBJECT reminds me that the tcg s390x port is now prepared
> to implement channel insns, but previously there were no
> channels worth talking about:
> 
>> /* I/O Instructions.  For each we simply indicate non-operation.  */
>>    C(0xb276, XSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb230, CSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb231, HSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb232, MSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb23b, RCHP,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb238, RSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb233, SSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb234, STSCH,   S,     Z,   0, 0, 0, 0, subchannel, 0)
>>    C(0xb235, TSCH,    S,     Z,   0, 0, 0, 0, subchannel, 0)
> 
> With a bit of help, I can make these emulated insns implement
> virtio as well.

Cool! I would assume that

  http://marc.info/?l=linux-s390&m=135488344028834&w=2

and most of this thread

  http://lists.gnu.org/archive/html/qemu-devel/2012-12/msg00837.html

would be enough help to actually implement them. Though I'd personally prefer if we can get the IBM folks to do a proper implementation that works for KVM first. Once that is there, doing the rest of the plumbing shouldn't be too hard.


Alex

Patch

diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
index 9e1afb2..f29ff74 100644
--- a/hw/s390-virtio.c
+++ b/hw/s390-virtio.c
@@ -33,6 +33,8 @@ 
 
 #include "hw/s390-virtio-bus.h"
 #include "hw/s390x/sclp.h"
+#include "hw/s390x/css.h"
+#include "hw/s390x/virtio-ccw.h"
 
 //#define DEBUG_S390
 
@@ -47,6 +49,7 @@ 
 #define KVM_S390_VIRTIO_NOTIFY          0
 #define KVM_S390_VIRTIO_RESET           1
 #define KVM_S390_VIRTIO_SET_STATUS      2
+#define KVM_S390_VIRTIO_CCW_NOTIFY      3
 
 #define KERN_IMAGE_START                0x010000UL
 #define KERN_PARM_AREA                  0x010480UL
@@ -63,6 +66,7 @@ 
 
 static VirtIOS390Bus *s390_bus;
 static S390CPU **ipi_states;
+VirtioCcwBus *ccw_bus;
 
 S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
 {
@@ -76,15 +80,21 @@  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
 int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
 {
     int r = 0, i;
+    int cssid, ssid, schid, m;
+    SubchDev *sch;
 
     dprintf("KVM hypercall: %ld\n", hypercall);
     switch (hypercall) {
     case KVM_S390_VIRTIO_NOTIFY:
         if (mem > ram_size) {
-            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
-                                                               mem, &i);
-            if (dev) {
-                virtio_queue_notify(dev->vdev, i);
+            if (s390_bus) {
+                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
+                                                                   mem, &i);
+                if (dev) {
+                    virtio_queue_notify(dev->vdev, i);
+                } else {
+                    r = -EINVAL;
+                }
             } else {
                 r = -EINVAL;
             }
@@ -93,28 +103,49 @@  int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t hypercall)
         }
         break;
     case KVM_S390_VIRTIO_RESET:
-    {
-        VirtIOS390Device *dev;
-
-        dev = s390_virtio_bus_find_mem(s390_bus, mem);
-        virtio_reset(dev->vdev);
-        stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
-        s390_virtio_device_sync(dev);
-        s390_virtio_reset_idx(dev);
+        if (s390_bus) {
+            VirtIOS390Device *dev;
+
+            dev = s390_virtio_bus_find_mem(s390_bus, mem);
+            virtio_reset(dev->vdev);
+            stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
+            s390_virtio_device_sync(dev);
+            s390_virtio_reset_idx(dev);
+        } else {
+            r = -EINVAL;
+        }
         break;
-    }
     case KVM_S390_VIRTIO_SET_STATUS:
-    {
-        VirtIOS390Device *dev;
+        if (s390_bus) {
+            VirtIOS390Device *dev;
 
-        dev = s390_virtio_bus_find_mem(s390_bus, mem);
-        if (dev) {
-            s390_virtio_device_update_status(dev);
+            dev = s390_virtio_bus_find_mem(s390_bus, mem);
+            if (dev) {
+                s390_virtio_device_update_status(dev);
+            } else {
+                r = -EINVAL;
+            }
         } else {
             r = -EINVAL;
         }
         break;
-    }
+    case KVM_S390_VIRTIO_CCW_NOTIFY:
+        if (ccw_bus) {
+            if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid, &ssid,
+                                             &schid)) {
+                r = -EINVAL;
+            } else {
+                sch = css_find_subch(m, cssid, ssid, schid);
+                if (sch && css_subch_visible(sch)) {
+                    virtio_queue_notify(virtio_ccw_get_vdev(sch), env->regs[3]);
+                } else {
+                    r = -EINVAL;
+                }
+            }
+         } else {
+             r = -EINVAL;
+         }
+         break;
     default:
         r = -EINVAL;
         break;
@@ -370,7 +401,6 @@  static QEMUMachine s390_machine = {
     .no_sdcard = 1,
     .use_virtcon = 1,
     .max_cpus = 255,
-    .is_default = 1,
 };
 
 static void s390_machine_init(void)
@@ -379,3 +409,82 @@  static void s390_machine_init(void)
 }
 
 machine_init(s390_machine_init);
+
+static void ccw_init(QEMUMachineInitArgs *args)
+{
+    ram_addr_t my_ram_size = args->ram_size;
+    ram_addr_t ram_size = args->ram_size;
+    const char *cpu_model = args->cpu_model;
+    const char *kernel_filename = args->kernel_filename;
+    const char *kernel_cmdline = args->kernel_cmdline;
+    const char *initrd_filename = args->initrd_filename;
+    CPUS390XState *env = NULL;
+    MemoryRegion *sysmem = get_system_memory();
+    MemoryRegion *ram = g_new(MemoryRegion, 1);
+    int shift = 0;
+    uint8_t *storage_keys;
+    int ret;
+
+    /* s390x ram size detection needs a 16bit multiplier + an increment. So
+       guests > 64GB can be specified in 2MB steps etc. */
+    while ((my_ram_size >> (20 + shift)) > 65535) {
+        shift++;
+    }
+    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
+
+    /* lets propagate the changed ram size into the global variable. */
+    ram_size = my_ram_size;
+
+    /* get a BUS */
+    ccw_bus = virtio_ccw_bus_init();
+    s390_sclp_init();
+
+    /* allocate RAM */
+    memory_region_init_ram(ram, "s390.ram", my_ram_size);
+    vmstate_register_ram_global(ram);
+    memory_region_add_subregion(sysmem, 0, ram);
+
+    /* allocate storage keys */
+    storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
+
+    /* init CPUs */
+    env = s390_init_cpus(cpu_model, storage_keys);
+
+    kvm_s390_enable_css_support(env);
+
+    /*
+     * Create virtual css and set it as default so that non mcss-e
+     * enabled guests only see virtio devices.
+     */
+    ret = css_create_css_image(VIRTUAL_CSSID, true);
+    assert(ret == 0);
+
+
+    s390_set_up_kernel(env, kernel_filename, kernel_cmdline, initrd_filename);
+
+    /* Create VirtIO network adapters */
+    s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
+
+}
+
+static QEMUMachine ccw_machine = {
+    .name = "s390-ccw-virtio",
+    .alias = "s390-ccw",
+    .desc = "VirtIO-ccw based S390 machine",
+    .init = ccw_init,
+    .no_cdrom = 1,
+    .no_floppy = 1,
+    .no_serial = 1,
+    .no_parallel = 1,
+    .no_sdcard = 1,
+    .use_virtcon = 1,
+    .max_cpus = 255,
+    .is_default = 1,
+};
+
+static void ccw_machine_init(void)
+{
+    qemu_register_machine(&ccw_machine);
+}
+
+machine_init(ccw_machine_init);
diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index 378b099..d408558 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -5,3 +5,4 @@  obj-y += sclp.o
 obj-y += event-facility.o
 obj-y += sclpquiesce.o sclpconsole.o
 obj-y += css.o
+obj-y += virtio-ccw.o
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
new file mode 100644
index 0000000..b4624ab
--- /dev/null
+++ b/hw/s390x/virtio-ccw.c
@@ -0,0 +1,909 @@ 
+/*
+ * virtio ccw target implementation
+ *
+ * Copyright 2012 IBM Corp.
+ * Author(s): Cornelia Huck <cornelia.huck@de.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 <hw/hw.h>
+#include "block.h"
+#include "blockdev.h"
+#include "sysemu.h"
+#include "net.h"
+#include "monitor.h"
+#include "qemu-thread.h"
+#include "hw/virtio.h"
+#include "hw/virtio-serial.h"
+#include "hw/virtio-net.h"
+#include "hw/sysbus.h"
+#include "bitops.h"
+
+#include "ioinst.h"
+#include "css.h"
+#include "virtio-ccw.h"
+#include "trace.h"
+
+static const TypeInfo virtio_ccw_bus_info = {
+    .name = TYPE_VIRTIO_CCW_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(VirtioCcwBus),
+};
+
+static const VirtIOBindings virtio_ccw_bindings;
+
+VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
+{
+    VirtIODevice *vdev = NULL;
+
+    if (sch->driver_data) {
+        vdev = ((VirtioCcwData *)sch->driver_data)->vdev;
+    }
+    return vdev;
+}
+
+static void virtio_ccw_reset_subchannels(void *opaque)
+{
+    VirtioCcwBus *bus = opaque;
+    BusChild *kid;
+    VirtioCcwData *data;
+
+    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
+        data = (VirtioCcwData *)kid->child;
+        virtio_reset(data->vdev);
+        css_reset_sch(data->sch);
+    }
+    css_reset();
+}
+
+VirtioCcwBus *virtio_ccw_bus_init(void)
+{
+    VirtioCcwBus *cbus;
+    BusState *bus;
+    DeviceState *dev;
+
+    /* Create bridge device */
+    dev = qdev_create(NULL, "virtio-ccw-bridge");
+    qdev_init_nofail(dev);
+
+    /* Create bus on bridge device */
+    bus = qbus_create(TYPE_VIRTIO_CCW_BUS, dev, "virtio-ccw");
+    cbus = DO_UPCAST(VirtioCcwBus, bus, bus);
+
+    /* Enable hotplugging */
+    bus->allow_hotplug = 1;
+
+    qemu_register_reset(virtio_ccw_reset_subchannels, cbus);
+    return cbus;
+}
+
+/* Communication blocks used by several channel commands. */
+typedef struct VqInfoBlock {
+    uint64_t queue;
+    uint32_t align;
+    uint16_t index;
+    uint16_t num;
+} QEMU_PACKED VqInfoBlock;
+
+typedef struct VqConfigBlock {
+    uint16_t index;
+    uint16_t num_max;
+} QEMU_PACKED VqConfigBlock;
+
+typedef struct VirtioFeatDesc {
+    uint32_t features;
+    uint8_t index;
+} QEMU_PACKED VirtioFeatDesc;
+
+/* Specify where the virtqueues for the subchannel are in guest memory. */
+static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t addr, uint32_t align,
+                              uint16_t index, uint16_t num)
+{
+    VirtioCcwData *data = sch->driver_data;
+
+    if (index > VIRTIO_PCI_QUEUE_MAX) {
+        return -EINVAL;
+    }
+
+    /* Current code in virtio.c relies on 4K alignment. */
+    if (addr && (align != 4096)) {
+        return -EINVAL;
+    }
+
+    if (!data) {
+        return -EINVAL;
+    }
+
+    virtio_queue_set_addr(data->vdev, index, addr);
+    if (!addr) {
+        virtio_queue_set_vector(data->vdev, index, 0);
+    } else {
+        /* Fail if we don't have a big enough queue. */
+        /* TODO: Add interface to handle vring.num changing */
+        if (virtio_queue_get_num(data->vdev, index) > num) {
+            return -EINVAL;
+        }
+        virtio_queue_set_vector(data->vdev, index, index);
+    }
+    /* tell notify handler in case of config change */
+    data->vdev->config_vector = VIRTIO_PCI_QUEUE_MAX;
+    return 0;
+}
+
+static int virtio_ccw_cb(SubchDev *sch, CCW1 *ccw)
+{
+    int ret;
+    VqInfoBlock info;
+    uint8_t status;
+    VirtioFeatDesc features;
+    void *config;
+    hwaddr indicators;
+    VqConfigBlock vq_config;
+    VirtioCcwData *data = sch->driver_data;
+    bool check_len;
+    int len;
+
+    if (!ccw) {
+        return -EIO;
+    }
+
+    if (!data) {
+        return -EINVAL;
+    }
+
+    trace_virtio_ccw_interpret_ccw(sch->cssid, sch->ssid, sch->schid,
+                                   ccw->cmd_code);
+    check_len = !((ccw->flags & CCW_FLAG_SLI) && !(ccw->flags & CCW_FLAG_DC));
+
+    /* Look at the command. */
+    switch (ccw->cmd_code) {
+    case CCW_CMD_SET_VQ:
+        if (check_len) {
+            if (ccw->count != sizeof(info)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(info)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        if (!qemu_get_ram_ptr(ccw->cda)) {
+            ret = -EFAULT;
+        } else {
+            info.queue = ldq_phys(ccw->cda);
+            info.align = ldl_phys(ccw->cda + sizeof(info.queue));
+            info.index = lduw_phys(ccw->cda + sizeof(info.queue)
+                                   + sizeof(info.align));
+            info.num = lduw_phys(ccw->cda + sizeof(info.queue)
+                                 + sizeof(info.align)
+                                 + sizeof(info.index));
+            ret = virtio_ccw_set_vqs(sch, info.queue, info.align, info.index,
+                                     info.num);
+            sch->curr_status.scsw.count = 0;
+        }
+        break;
+    case CCW_CMD_VDEV_RESET:
+        virtio_reset(data->vdev);
+        ret = 0;
+        break;
+    case CCW_CMD_READ_FEAT:
+        if (check_len) {
+            if (ccw->count != sizeof(features)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(features)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        if (!qemu_get_ram_ptr(ccw->cda)) {
+            ret = -EFAULT;
+        } else {
+            features.index = ldub_phys(ccw->cda + sizeof(features.features));
+            if (features.index < ARRAY_SIZE(data->host_features)) {
+                features.features = data->host_features[features.index];
+            } else {
+                /* Return zeroes if the guest supports more feature bits. */
+                features.features = 0;
+            }
+            stl_le_phys(ccw->cda, features.features);
+            sch->curr_status.scsw.count = ccw->count - sizeof(features);
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_WRITE_FEAT:
+        if (check_len) {
+            if (ccw->count != sizeof(features)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(features)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        if (!qemu_get_ram_ptr(ccw->cda)) {
+            ret = -EFAULT;
+        } else {
+            features.index = ldub_phys(ccw->cda + sizeof(features.features));
+            features.features = ldl_le_phys(ccw->cda);
+            if (features.index < ARRAY_SIZE(data->host_features)) {
+                if (data->vdev->set_features) {
+                    data->vdev->set_features(data->vdev, features.features);
+                }
+                data->vdev->guest_features = features.features;
+            } else {
+                /*
+                 * If the guest supports more feature bits, assert that it
+                 * passes us zeroes for those we don't support.
+                 */
+                if (features.features) {
+                    fprintf(stderr, "Guest bug: features[%i]=%x (expected 0)\n",
+                            features.index, features.features);
+                    /* XXX: do a unit check here? */
+                }
+            }
+            sch->curr_status.scsw.count = ccw->count - sizeof(features);
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_READ_CONF:
+        if (check_len) {
+            if (ccw->count > data->vdev->config_len) {
+                ret = -EINVAL;
+                break;
+            }
+        }
+        len = MIN(ccw->count, data->vdev->config_len);
+        if (!qemu_get_ram_ptr(ccw->cda)) {
+            ret = -EFAULT;
+        } else {
+            data->vdev->get_config(data->vdev, data->vdev->config);
+            cpu_physical_memory_write(ccw->cda, data->vdev->config, len);
+            sch->curr_status.scsw.count = ccw->count - len;
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_WRITE_CONF:
+        if (check_len) {
+            if (ccw->count > data->vdev->config_len) {
+                ret = -EINVAL;
+                break;
+            }
+        }
+        len = MIN(ccw->count, data->vdev->config_len);
+        config = qemu_get_ram_ptr(ccw->cda);
+        if (!config) {
+            ret = -EFAULT;
+        } else {
+            memcpy(data->vdev->config, config, len);
+            if (data->vdev->set_config) {
+                data->vdev->set_config(data->vdev, data->vdev->config);
+            }
+            sch->curr_status.scsw.count = ccw->count - len;
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_WRITE_STATUS:
+        if (check_len) {
+            if (ccw->count != sizeof(status)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(status)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        if (!qemu_get_ram_ptr(ccw->cda)) {
+            ret = -EFAULT;
+        } else {
+            status = ldub_phys(ccw->cda);
+            virtio_set_status(data->vdev, status);
+            sch->curr_status.scsw.count = ccw->count - sizeof(status);
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_SET_IND:
+        if (check_len) {
+            if (ccw->count != sizeof(indicators)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(indicators)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        indicators = ldq_phys(ccw->cda);
+        if (!indicators) {
+            ret = -EFAULT;
+        } else {
+            data->indicators = indicators;
+            sch->curr_status.scsw.count = ccw->count - sizeof(indicators);
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_SET_CONF_IND:
+        if (check_len) {
+            if (ccw->count != sizeof(indicators)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(indicators)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        indicators = ldq_phys(ccw->cda);
+        if (!indicators) {
+            ret = -EFAULT;
+        } else {
+            data->indicators2 = indicators;
+            sch->curr_status.scsw.count = ccw->count - sizeof(indicators);
+            ret = 0;
+        }
+        break;
+    case CCW_CMD_READ_VQ_CONF:
+        if (check_len) {
+            if (ccw->count != sizeof(vq_config)) {
+                ret = -EINVAL;
+                break;
+            }
+        } else if (ccw->count < sizeof(vq_config)) {
+            /* Can't execute command. */
+            ret = -EINVAL;
+            break;
+        }
+        if (!qemu_get_ram_ptr(ccw->cda)) {
+            ret = -EFAULT;
+        } else {
+            vq_config.index = lduw_phys(ccw->cda);
+            vq_config.num_max = virtio_queue_get_num(data->vdev,
+                                                     vq_config.index);
+            stw_phys(ccw->cda + sizeof(vq_config.index), vq_config.num_max);
+            sch->curr_status.scsw.count = ccw->count - sizeof(vq_config);
+            ret = 0;
+        }
+        break;
+    default:
+        ret = -EOPNOTSUPP;
+        break;
+    }
+    return ret;
+}
+
+static int virtio_ccw_device_init(VirtioCcwData *dev, VirtIODevice *vdev)
+{
+    unsigned int cssid = 0;
+    unsigned int ssid = 0;
+    unsigned int schid;
+    unsigned int devno;
+    bool have_devno = false;
+    bool found = false;
+    SubchDev *sch;
+    int ret;
+    int num;
+
+    sch = g_malloc0(sizeof(SubchDev));
+
+    sch->driver_data = dev;
+    dev->sch = sch;
+
+    dev->vdev = vdev;
+    dev->indicators = 0;
+
+    /* Initialize subchannel structure. */
+    sch->channel_prog = NULL;
+    sch->last_cmd = NULL;
+    sch->orb = NULL;
+    /*
+     * Use a device number if provided. Otherwise, fall back to subchannel
+     * number.
+     */
+    if (dev->bus_id) {
+        num = sscanf(dev->bus_id, "%x.%x.%04x", &cssid, &ssid, &devno);
+        if (num == 3) {
+            if ((cssid > MAX_CSSID) || (ssid > MAX_SSID)) {
+                ret = -EINVAL;
+                error_report("Invalid cssid or ssid: cssid %x, ssid %x",
+                             cssid, ssid);
+                goto out_err;
+            }
+            /* Enforce use of virtual cssid. */
+            if (cssid != VIRTUAL_CSSID) {
+                ret = -EINVAL;
+                error_report("cssid %x not valid for virtio devices", cssid);
+                goto out_err;
+            }
+            if (css_devno_used(cssid, ssid, devno)) {
+                ret = -EEXIST;
+                error_report("Device %x.%x.%04x already exists", cssid, ssid,
+                             devno);
+                goto out_err;
+            }
+            sch->cssid = cssid;
+            sch->ssid = ssid;
+            sch->devno = devno;
+            have_devno = true;
+        } else {
+            ret = -EINVAL;
+            error_report("Malformed devno parameter '%s'", dev->bus_id);
+            goto out_err;
+        }
+    }
+
+    /* Find the next free id. */
+    if (have_devno) {
+        for (schid = 0; schid <= MAX_SCHID; schid++) {
+            if (!css_find_subch(1, cssid, ssid, schid)) {
+                sch->schid = schid;
+                css_subch_assign(cssid, ssid, schid, devno, sch);
+                found = true;
+                break;
+            }
+        }
+        if (!found) {
+            ret = -ENODEV;
+            error_report("No free subchannel found for %x.%x.%04x", cssid, ssid,
+                         devno);
+            goto out_err;
+        }
+        trace_virtio_ccw_new_device(cssid, ssid, schid, devno, "user-configured");
+    } else {
+        cssid = VIRTUAL_CSSID;
+        for (ssid = 0; ssid <= MAX_SSID; ssid++) {
+            for (schid = 0; schid <= MAX_SCHID; schid++) {
+                if (!css_find_subch(1, cssid, ssid, schid)) {
+                    sch->cssid = cssid;
+                    sch->ssid = ssid;
+                    sch->schid = schid;
+                    devno = schid;
+                    /*
+                     * If the devno is already taken, look further in this
+                     * subchannel set.
+                     */
+                    while (css_devno_used(cssid, ssid, devno)) {
+                        if (devno == MAX_SCHID) {
+                            devno = 0;
+                        } else if (devno == schid - 1) {
+                            ret = -ENODEV;
+                            error_report("No free devno found");
+                            goto out_err;
+                        } else {
+                            devno++;
+                        }
+                    }
+                    sch->devno = devno;
+                    css_subch_assign(cssid, ssid, schid, devno, sch);
+                    found = true;
+                    break;
+                }
+            }
+            if (found) {
+                break;
+            }
+        }
+        if (!found) {
+            ret = -ENODEV;
+            error_report("Virtual channel subsystem is full!");
+            goto out_err;
+        }
+        trace_virtio_ccw_new_device(cssid, ssid, schid, devno, "auto-configured");
+    }
+
+    /* Build initial schib. */
+    css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);
+
+    sch->ccw_cb = virtio_ccw_cb;
+
+    /* Build senseid data. */
+    memset(&sch->id, 0, sizeof(SenseId));
+    sch->id.reserved = 0xff;
+    sch->id.cu_type = VIRTIO_CCW_CU_TYPE;
+    sch->id.cu_model = dev->vdev->device_id;
+
+    virtio_bind_device(vdev, &virtio_ccw_bindings, dev);
+    /* Only the first 32 feature bits are used. */
+    dev->host_features[0] = vdev->get_features(vdev, dev->host_features[0]);
+    dev->host_features[0] |= 0x1 << VIRTIO_F_NOTIFY_ON_EMPTY;
+    dev->host_features[0] |= 0x1 << VIRTIO_F_BAD_FEATURE;
+
+    css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
+                          dev->qdev.hotplugged, 1);
+    return 0;
+
+out_err:
+    dev->sch = NULL;
+    g_free(sch);
+    return ret;
+}
+
+static int virtio_ccw_exit(VirtioCcwData *dev)
+{
+    SubchDev *sch = dev->sch;
+
+    if (sch) {
+        css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
+        g_free(sch);
+    }
+    dev->indicators = 0;
+    return 0;
+}
+
+static int virtio_ccw_net_init(VirtioCcwData *dev)
+{
+    VirtIODevice *vdev;
+
+    vdev = virtio_net_init((DeviceState *)dev, &dev->nic, &dev->net);
+    if (!vdev) {
+        return -1;
+    }
+
+    return virtio_ccw_device_init(dev, vdev);
+}
+
+static int virtio_ccw_net_exit(VirtioCcwData *dev)
+{
+    virtio_net_exit(dev->vdev);
+    return virtio_ccw_exit(dev);
+}
+
+static int virtio_ccw_blk_init(VirtioCcwData *dev)
+{
+    VirtIODevice *vdev;
+
+    vdev = virtio_blk_init((DeviceState *)dev, &dev->blk);
+    if (!vdev) {
+        return -1;
+    }
+
+    return virtio_ccw_device_init(dev, vdev);
+}
+
+static int virtio_ccw_blk_exit(VirtioCcwData *dev)
+{
+    virtio_blk_exit(dev->vdev);
+    blockdev_mark_auto_del(dev->blk.conf.bs);
+    return virtio_ccw_exit(dev);
+}
+
+static int virtio_ccw_serial_init(VirtioCcwData *dev)
+{
+    VirtioCcwBus *bus;
+    VirtIODevice *vdev;
+    int r;
+
+    bus = DO_UPCAST(VirtioCcwBus, bus, dev->qdev.parent_bus);
+
+    vdev = virtio_serial_init((DeviceState *)dev, &dev->serial);
+    if (!vdev) {
+        return -1;
+    }
+
+    r = virtio_ccw_device_init(dev, vdev);
+    if (!r) {
+        bus->console = dev;
+    }
+
+    return r;
+}
+
+static int virtio_ccw_serial_exit(VirtioCcwData *dev)
+{
+    VirtioCcwBus *bus;
+
+    bus = DO_UPCAST(VirtioCcwBus, bus, dev->qdev.parent_bus);
+    bus->console = NULL;
+    virtio_serial_exit(dev->vdev);
+    return virtio_ccw_exit(dev);
+}
+
+static int virtio_ccw_balloon_init(VirtioCcwData *dev)
+{
+    VirtIODevice *vdev;
+
+    vdev = virtio_balloon_init((DeviceState *)dev);
+    if (!vdev) {
+        return -1;
+    }
+
+    return virtio_ccw_device_init(dev, vdev);
+}
+
+static int virtio_ccw_balloon_exit(VirtioCcwData *dev)
+{
+    virtio_balloon_exit(dev->vdev);
+    return virtio_ccw_exit(dev);
+}
+
+static int virtio_ccw_scsi_init(VirtioCcwData *dev)
+{
+    VirtIODevice *vdev;
+
+    vdev = virtio_scsi_init((DeviceState *)dev, &dev->scsi);
+    if (!vdev) {
+        return -1;
+    }
+
+    return virtio_ccw_device_init(dev, vdev);
+}
+
+static int virtio_ccw_scsi_exit(VirtioCcwData *dev)
+{
+    virtio_scsi_exit(dev->vdev);
+    return virtio_ccw_exit(dev);
+}
+
+VirtioCcwData *virtio_ccw_bus_console(VirtioCcwBus *bus)
+{
+    return bus->console;
+}
+
+static void virtio_ccw_notify(void *opaque, uint16_t vector)
+{
+    VirtioCcwData *dev = opaque;
+    SubchDev *sch = dev->sch;
+    uint64_t indicators;
+
+    if (vector >= 128) {
+        return;
+    }
+
+    if (vector < VIRTIO_PCI_QUEUE_MAX) {
+        indicators = ldq_phys(dev->indicators);
+        set_bit(vector, &indicators);
+        stq_phys(dev->indicators, indicators);
+    } else {
+        vector = 0;
+        indicators = ldq_phys(dev->indicators2);
+        set_bit(vector, &indicators);
+        stq_phys(dev->indicators2, indicators);
+    }
+
+    css_conditional_io_interrupt(sch);
+
+}
+
+static unsigned virtio_ccw_get_features(void *opaque)
+{
+    VirtioCcwData *dev = opaque;
+
+    /* Only the first 32 feature bits are used. */
+    return dev->host_features[0];
+}
+
+/**************** Virtio-ccw Bus Device Descriptions *******************/
+
+static const VirtIOBindings virtio_ccw_bindings = {
+    .notify = virtio_ccw_notify,
+    .get_features = virtio_ccw_get_features,
+};
+
+static Property virtio_ccw_net_properties[] = {
+    DEFINE_PROP_STRING("devno", VirtioCcwData, bus_id),
+    DEFINE_VIRTIO_NET_FEATURES(VirtioCcwData, host_features[0]),
+    DEFINE_NIC_PROPERTIES(VirtioCcwData, nic),
+    DEFINE_PROP_UINT32("x-txtimer", VirtioCcwData,
+                       net.txtimer, TX_TIMER_INTERVAL),
+    DEFINE_PROP_INT32("x-txburst", VirtioCcwData,
+                      net.txburst, TX_BURST),
+    DEFINE_PROP_STRING("tx", VirtioCcwData, net.tx),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_ccw_net_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
+
+    k->init = virtio_ccw_net_init;
+    k->exit = virtio_ccw_net_exit;
+    dc->props = virtio_ccw_net_properties;
+}
+
+static TypeInfo virtio_ccw_net = {
+    .name          = "virtio-net-ccw",
+    .parent        = TYPE_VIRTIO_CCW_DEVICE,
+    .instance_size = sizeof(VirtioCcwData),
+    .class_init    = virtio_ccw_net_class_init,
+};
+
+static Property virtio_ccw_blk_properties[] = {
+    DEFINE_PROP_STRING("devno", VirtioCcwData, bus_id),
+    DEFINE_BLOCK_PROPERTIES(VirtioCcwData, blk.conf),
+    DEFINE_PROP_STRING("serial", VirtioCcwData, blk.serial),
+#ifdef __linux__
+    DEFINE_PROP_BIT("scsi", VirtioCcwData, blk.scsi, 0, true),
+#endif
+    DEFINE_VIRTIO_BLK_FEATURES(VirtioCcwData, host_features[0]),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_ccw_blk_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
+
+    k->init = virtio_ccw_blk_init;
+    k->exit = virtio_ccw_blk_exit;
+    dc->props = virtio_ccw_blk_properties;
+}
+
+static TypeInfo virtio_ccw_blk = {
+    .name          = "virtio-blk-ccw",
+    .parent        = TYPE_VIRTIO_CCW_DEVICE,
+    .instance_size = sizeof(VirtioCcwData),
+    .class_init    = virtio_ccw_blk_class_init,
+};
+
+static Property virtio_ccw_serial_properties[] = {
+    DEFINE_PROP_STRING("devno", VirtioCcwData, bus_id),
+    DEFINE_PROP_UINT32("max_ports", VirtioCcwData, serial.max_virtserial_ports,
+                       31),
+    DEFINE_VIRTIO_COMMON_FEATURES(VirtioCcwData, host_features[0]),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_ccw_serial_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
+
+    k->init = virtio_ccw_serial_init;
+    k->exit = virtio_ccw_serial_exit;
+    dc->props = virtio_ccw_serial_properties;
+}
+
+static TypeInfo virtio_ccw_serial = {
+    .name          = "virtio-serial-ccw",
+    .parent        = TYPE_VIRTIO_CCW_DEVICE,
+    .instance_size = sizeof(VirtioCcwData),
+    .class_init    = virtio_ccw_serial_class_init,
+};
+
+static Property virtio_ccw_balloon_properties[] = {
+    DEFINE_PROP_STRING("devno", VirtioCcwData, bus_id),
+    DEFINE_VIRTIO_COMMON_FEATURES(VirtioCcwData, host_features[0]),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_ccw_balloon_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
+
+    k->init = virtio_ccw_balloon_init;
+    k->exit = virtio_ccw_balloon_exit;
+    dc->props = virtio_ccw_balloon_properties;
+}
+
+static TypeInfo virtio_ccw_balloon = {
+    .name          = "virtio-balloon-ccw",
+    .parent        = TYPE_VIRTIO_CCW_DEVICE,
+    .instance_size = sizeof(VirtioCcwData),
+    .class_init    = virtio_ccw_balloon_class_init,
+};
+
+static Property virtio_ccw_scsi_properties[] = {
+    DEFINE_PROP_STRING("devno", VirtioCcwData, bus_id),
+    DEFINE_VIRTIO_SCSI_PROPERTIES(VirtioCcwData, host_features[0], scsi),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_ccw_scsi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
+
+    k->init = virtio_ccw_scsi_init;
+    k->exit = virtio_ccw_scsi_exit;
+    dc->props = virtio_ccw_scsi_properties;
+}
+
+static TypeInfo virtio_ccw_scsi = {
+    .name          = "virtio-scsi-ccw",
+    .parent        = TYPE_VIRTIO_CCW_DEVICE,
+    .instance_size = sizeof(VirtioCcwData),
+    .class_init    = virtio_ccw_scsi_class_init,
+};
+
+static int virtio_ccw_busdev_init(DeviceState *dev)
+{
+    VirtioCcwData *_dev = (VirtioCcwData *)dev;
+    VirtIOCCWDeviceClass *_info = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
+
+    return _info->init(_dev);
+}
+
+static int virtio_ccw_busdev_exit(DeviceState *dev)
+{
+    VirtioCcwData *_dev = (VirtioCcwData *)dev;
+    VirtIOCCWDeviceClass *_info = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
+
+    return _info->exit(_dev);
+}
+
+static int virtio_ccw_busdev_unplug(DeviceState *dev)
+{
+    VirtioCcwData *_dev = (VirtioCcwData *)dev;
+    SubchDev *sch = _dev->sch;
+
+    /*
+     * We should arrive here only for device_del, since we don't support
+     * direct hot(un)plug of channels, but only through virtio.
+     */
+    assert(sch != NULL);
+    /* Subchannel is now disabled and no longer valid. */
+    sch->curr_status.pmcw.flags &= ~(PMCW_FLAGS_MASK_ENA |
+                                     PMCW_FLAGS_MASK_DNV);
+
+    css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
+
+    object_unparent(OBJECT(dev));
+    qdev_free(dev);
+    return 0;
+}
+
+static void virtio_ccw_device_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->init = virtio_ccw_busdev_init;
+    dc->exit = virtio_ccw_busdev_exit;
+    dc->unplug = virtio_ccw_busdev_unplug;
+    dc->bus_type = TYPE_VIRTIO_CCW_BUS;
+
+}
+
+static TypeInfo virtio_ccw_device_info = {
+    .name = TYPE_VIRTIO_CCW_DEVICE,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(VirtioCcwData),
+    .class_init = virtio_ccw_device_class_init,
+    .class_size = sizeof(VirtIOCCWDeviceClass),
+    .abstract = true,
+};
+
+/***************** Virtio-ccw Bus Bridge Device ********************/
+/* Only required to have the virtio bus as child in the system bus */
+
+static int virtio_ccw_bridge_init(SysBusDevice *dev)
+{
+    /* nothing */
+    return 0;
+}
+
+static void virtio_ccw_bridge_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+    k->init = virtio_ccw_bridge_init;
+    dc->no_user = 1;
+}
+
+static TypeInfo virtio_ccw_bridge_info = {
+    .name          = "virtio-ccw-bridge",
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SysBusDevice),
+    .class_init    = virtio_ccw_bridge_class_init,
+};
+
+static void virtio_ccw_register(void)
+{
+    type_register_static(&virtio_ccw_bus_info);
+    type_register_static(&virtio_ccw_device_info);
+    type_register_static(&virtio_ccw_serial);
+    type_register_static(&virtio_ccw_blk);
+    type_register_static(&virtio_ccw_net);
+    type_register_static(&virtio_ccw_balloon);
+    type_register_static(&virtio_ccw_scsi);
+    type_register_static(&virtio_ccw_bridge_info);
+}
+type_init(virtio_ccw_register);
diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
new file mode 100644
index 0000000..f0dee1e
--- /dev/null
+++ b/hw/s390x/virtio-ccw.h
@@ -0,0 +1,81 @@ 
+/*
+ * virtio ccw target definitions
+ *
+ * Copyright 2012 IBM Corp.
+ * Author(s): Cornelia Huck <cornelia.huck@de.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 <hw/virtio-blk.h>
+#include <hw/virtio-net.h>
+#include <hw/virtio-serial.h>
+#include <hw/virtio-scsi.h>
+
+#define VIRTUAL_CSSID 0xfe
+
+#define VIRTIO_CCW_CU_TYPE 0x3832
+#define VIRTIO_CCW_CHPID_TYPE 0x32
+
+#define CCW_CMD_SET_VQ       0x13
+#define CCW_CMD_VDEV_RESET   0x33
+#define CCW_CMD_READ_FEAT    0x12
+#define CCW_CMD_WRITE_FEAT   0x11
+#define CCW_CMD_READ_CONF    0x22
+#define CCW_CMD_WRITE_CONF   0x21
+#define CCW_CMD_WRITE_STATUS 0x31
+#define CCW_CMD_SET_IND      0x43
+#define CCW_CMD_SET_CONF_IND 0x53
+#define CCW_CMD_READ_VQ_CONF 0x32
+
+#define TYPE_VIRTIO_CCW_DEVICE "virtio-ccw-device"
+#define VIRTIO_CCW_DEVICE(obj) \
+     OBJECT_CHECK(VirtioCcwData, (obj), TYPE_VIRTIO_CCW_DEVICE)
+#define VIRTIO_CCW_DEVICE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(VirtIOCCWDeviceClass, (klass), TYPE_VIRTIO_CCW_DEVICE)
+#define VIRTIO_CCW_DEVICE_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(VirtIOCCWDeviceClass, (obj), TYPE_VIRTIO_CCW_DEVICE)
+
+#define TYPE_VIRTIO_CCW_BUS "virtio-ccw-bus"
+#define VIRTIO_CCW_BUS(obj) \
+     OBJECT_CHECK(VirtioCcwBus, (obj), TYPE_VIRTIO_CCW_BUS)
+
+typedef struct VirtioCcwData VirtioCcwData;
+
+typedef struct VirtIOCCWDeviceClass {
+    DeviceClass qdev;
+    int (*init)(VirtioCcwData *dev);
+    int (*exit)(VirtioCcwData *dev);
+} VirtIOCCWDeviceClass;
+
+/* Change here if we want to support more feature bits. */
+#define VIRTIO_CCW_FEATURE_SIZE 1
+
+struct VirtioCcwData {
+    DeviceState qdev;
+    SubchDev *sch;
+    VirtIODevice *vdev;
+    char *bus_id;
+    VirtIOBlkConf blk;
+    NICConf nic;
+    uint32_t host_features[VIRTIO_CCW_FEATURE_SIZE];
+    virtio_serial_conf serial;
+    virtio_net_conf net;
+    VirtIOSCSIConf scsi;
+    /* Guest provided values: */
+    hwaddr indicators;
+    hwaddr indicators2;
+};
+
+/* virtio-ccw bus type */
+typedef struct VirtioCcwBus {
+    BusState bus;
+    VirtioCcwData *console;
+} VirtioCcwBus;
+
+VirtioCcwBus *virtio_ccw_bus_init(void);
+void virtio_ccw_device_update_status(SubchDev *sch);
+VirtioCcwData *virtio_ccw_bus_console(VirtioCcwBus *bus);
+VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch);
diff --git a/trace-events b/trace-events
index ef44b1e..743bcba 100644
--- a/trace-events
+++ b/trace-events
@@ -1036,3 +1036,7 @@  css_chpid_add(uint8_t cssid, uint8_t chpid, uint8_t type) "CSS: add chpid %x.%02
 css_new_image(uint8_t cssid, const char *default_cssid) "CSS: add css image %02x %s"
 css_assign_subch(const char *do_assign, uint8_t cssid, uint8_t ssid, uint16_t schid, uint16_t devno) "CSS: %s %x.%x.%04x (devno %04x)"
 css_io_interrupt(int cssid, int ssid, int schid, uint32_t intparm, uint8_t isc, const char *conditional) "CSS: I/O interrupt on sch %x.%x.%04x (intparm %08x, isc %x) %s"
+
+# hw/s390x/virtio-ccw.c
+virtio_ccw_interpret_ccw(int cssid, int ssid, int schid, int cmd_code) "VIRTIO-CCW: %x.%x.%04x: interpret command %x"
+virtio_ccw_new_device(int cssid, int ssid, int schid, int devno, const char *devno_mode) "VIRTIO-CCW: add subchannel %x.%x.%04x, devno %04x (%s)"