Re: [Qemu-devel] [PATCH/RFC] s390x/kvm: implement and use QEMU config device for s390

[Paolo Bonzini <pbonzini@redhat.com>]

Il 01/04/2014 16:47, Christian Borntraeger ha scritto:
> From: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
>
> The following patch adds Qemu CONFIG device,
> which interacts with kvm CONFIG device by calling KVM_CREATE_DEVICE
> (to create the device in kernel), KVM_GET_DEVICE_ATTR and
> KVM_SET_DEVICE_ATTR (to get and set the particular attributes of
> KVM CONFIG device respectively).
> This patch uses the Qemu CONFIG device to copy the
> qemu_name (if specified) into the kvm CONFIG device.
>
> Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>

On the QEMU side we'll soon have per-machine-type options in -machine. 
s390 can then use that.

Paolo

> ---
>  default-configs/s390x-softmmu.mak |   1 +
>  hw/s390x/Makefile.objs            |   1 +
>  hw/s390x/config.c                 | 113 ++++++++++++++++++++++++++++++++++++++
>  hw/s390x/s390-virtio-ccw.c        |   6 ++
>  hw/s390x/s390-virtio.c            |  24 ++++++++
>  hw/s390x/s390-virtio.h            |   1 +
>  include/hw/s390x/config.h         |  51 +++++++++++++++++
>  linux-headers/asm-s390/kvm.h      |  11 ++++
>  linux-headers/linux/kvm.h         |   1 +
>  trace-events                      |   4 ++
>  10 files changed, 213 insertions(+)
>  create mode 100644 hw/s390x/config.c
>  create mode 100644 include/hw/s390x/config.h
>
> diff --git a/default-configs/s390x-softmmu.mak b/default-configs/s390x-softmmu.mak
> index d843dc0..a07697d 100644
> --- a/default-configs/s390x-softmmu.mak
> +++ b/default-configs/s390x-softmmu.mak
> @@ -1,3 +1,4 @@
>  CONFIG_VIRTIO=y
>  CONFIG_SCLPCONSOLE=y
>  CONFIG_S390_FLIC=$(CONFIG_KVM)
> +CONFIG_S390_CONFIG=$(CONFIG_KVM)
> diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> index 1ba6c3a..dc03e1d 100644
> --- a/hw/s390x/Makefile.objs
> +++ b/hw/s390x/Makefile.objs
> @@ -8,3 +8,4 @@ obj-y += ipl.o
>  obj-y += css.o
>  obj-y += s390-virtio-ccw.o
>  obj-y += virtio-ccw.o
> +obj-$(CONFIG_S390_CONFIG) += config.o
> diff --git a/hw/s390x/config.c b/hw/s390x/config.c
> new file mode 100644
> index 0000000..f70e880
> --- /dev/null
> +++ b/hw/s390x/config.c
> @@ -0,0 +1,113 @@
> +/*
> + * S390 configuration and control device
> + *
> + * Copyright 2014 IBM Corp.
> + * Author(s): Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +
> +#include <sys/ioctl.h>
> +#include "hw/s390x/config.h"
> +#include "trace.h"
> +
> +S390ConfigState *get_config_state(void)
> +{
> +    return S390_CONFIG(object_resolve_path("/machine/s390-config", NULL));
> +}
> +
> +static int config_set(S390ConfigState *config, struct kvm_device_attr *attr)
> +{
> +    int rc;
> +
> +    rc = ioctl(config->fd, KVM_SET_DEVICE_ATTR, attr);
> +    return rc < 0 ? -errno : rc;
> +}
> +
> +/*
> +static int config_get(S390ConfigState *config, struct kvm_device_attr *attr)
> +{
> +    int rc;
> +
> +    rc = ioctl(config->fd, KVM_GET_DEVICE_ATTR, attr);
> +    return rc < 0 ? -errno : rc;
> +}
> +*/
> +
> +static int config_set_name(S390ConfigState *config, char *name)
> +{
> +    struct kvm_device_attr attr = {
> +        .group = KVM_DEV_CONFIG_GROUP,
> +        .attr  = KVM_DEV_CONFIG_NAME,
> +        .addr  = (uint64_t)name,
> +    };
> +
> +    if (!name ||
> +        (qemu_strnlen(name, S390_MACHINE_NAME_SIZE)
> +         >= S390_MACHINE_NAME_SIZE)) {
> +        return -EINVAL;
> +    }
> +
> +    return config_set(config, &attr);
> +}
> +
> +static void s390_config_realize(DeviceState *dev, Error **errp)
> +{
> +    S390ConfigState *cfg = S390_CONFIG(dev);
> +    struct kvm_create_device cd = {0};
> +    int ret;
> +
> +    if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
> +        trace_config_no_device_api(errno);
> +        return;
> +    }
> +
> +    cd.type = KVM_DEV_TYPE_S390_CONFIG;
> +    ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
> +    if (ret < 0) {
> +        trace_config_create_device(errno);
> +        return;
> +    }
> +    cfg->fd = cd.fd;
> +}
> +
> +void s390_config_dev_init(void)
> +{
> +    DeviceState *dev;
> +
> +    if (kvm_enabled()) {
> +        dev  = qdev_create(NULL, TYPE_S390_CONFIG);
> +
> +        object_property_add_child(qdev_get_machine(),
> +                                  TYPE_S390_CONFIG,
> +                                  OBJECT(dev), NULL);
> +        qdev_init_nofail(dev);
> +    }
> +}
> +
> +static void s390_config_class_init(ObjectClass *oc, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +    S390ConfigClass *scc = S390_CONFIG_CLASS(oc);
> +
> +    dc->realize = s390_config_realize;
> +    scc->set_name = config_set_name;
> +}
> +
> +static const TypeInfo s390_config_info = {
> +    .name          = TYPE_S390_CONFIG,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(S390ConfigState),
> +    .class_init    = s390_config_class_init,
> +    .class_size    = sizeof(S390ConfigClass),
> +};
> +
> +
> +static void s390_config_register_types(void)
> +{
> +    type_register_static(&s390_config_info);
> +}
> +
> +type_init(s390_config_register_types)
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 0d4f6ae..1e4b9ad 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -14,9 +14,11 @@
>  #include "s390-virtio.h"
>  #include "hw/s390x/sclp.h"
>  #include "hw/s390x/s390_flic.h"
> +#include "hw/s390x/config.h"
>  #include "ioinst.h"
>  #include "css.h"
>  #include "virtio-ccw.h"
> +#include "qemu/error-report.h"
>
>  void io_subsystem_reset(void)
>  {
> @@ -106,6 +108,10 @@ static void ccw_init(QEMUMachineInitArgs *args)
>                        args->initrd_filename, "s390-ccw.img");
>      s390_flic_init();
>
> +    s390_config_dev_init();
> +
> +    s390_set_vm_name();
> +
>      /* register hypercalls */
>      virtio_ccw_register_hcalls();
>
> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
> index aef2003..7a296fd 100644
> --- a/hw/s390x/s390-virtio.c
> +++ b/hw/s390x/s390-virtio.c
> @@ -39,6 +39,8 @@
>  #include "hw/s390x/s390_flic.h"
>  #include "hw/s390x/s390-virtio.h"
>
> +#include "hw/s390x/config.h"
> +
>  //#define DEBUG_S390
>
>  #ifdef DEBUG_S390
> @@ -223,6 +225,24 @@ void s390_create_virtio_net(BusState *bus, const char *name)
>      }
>  }
>
> +void s390_set_vm_name(void)
> +{
> +    S390ConfigState *config = get_config_state();
> +    char machine_name[S390_MACHINE_NAME_SIZE];
> +    S390ConfigClass *scc;
> +
> +    if (!config || !qemu_name) {
> +        return;
> +    }
> +    strncpy(machine_name, qemu_name, sizeof(machine_name));
> +
> +    scc = S390_CONFIG_GET_CLASS(config);
> +
> +    if (scc->set_name(config, machine_name)) {
> +        error_report("Setting machine name failed: %m");
> +    }
> +}
> +
>  /* PC hardware initialisation */
>  static void s390_init(QEMUMachineInitArgs *args)
>  {
> @@ -252,6 +272,10 @@ static void s390_init(QEMUMachineInitArgs *args)
>                        args->initrd_filename, ZIPL_FILENAME);
>      s390_flic_init();
>
> +    s390_config_dev_init();
> +
> +    s390_set_vm_name();
> +
>      /* register hypercalls */
>      s390_virtio_register_hcalls();
>
> diff --git a/hw/s390x/s390-virtio.h b/hw/s390x/s390-virtio.h
> index 5c405e7..deca18e 100644
> --- a/hw/s390x/s390-virtio.h
> +++ b/hw/s390x/s390-virtio.h
> @@ -26,4 +26,5 @@ void s390_init_ipl_dev(const char *kernel_filename,
>                         const char *initrd_filename,
>                         const char *firmware);
>  void s390_create_virtio_net(BusState *bus, const char *name);
> +void s390_set_vm_name(void);
>  #endif
> diff --git a/include/hw/s390x/config.h b/include/hw/s390x/config.h
> new file mode 100644
> index 0000000..14d9b02
> --- /dev/null
> +++ b/include/hw/s390x/config.h
> @@ -0,0 +1,51 @@
> +/*
> + * S390 configuration and control device
> + *
> + * Copyright 2014 IBM Corp.
> + * Author(s): Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +
> +#ifndef __KVM_S390_CONFIG_H
> +#define __KVM_S390_CONFIG_H
> +
> +#include "hw/sysbus.h"
> +#include "migration/qemu-file.h"
> +
> +#define TYPE_S390_CONFIG "s390-config"
> +#define S390_CONFIG(obj) \
> +    OBJECT_CHECK(S390ConfigState, (obj), TYPE_S390_CONFIG)
> +#define S390_CONFIG_CLASS(class) \
> +     OBJECT_CLASS_CHECK(S390ConfigClass, (class), TYPE_S390_CONFIG)
> +#define S390_CONFIG_GET_CLASS(obj) \
> +     OBJECT_GET_CLASS(S390ConfigClass, (obj), TYPE_S390_CONFIG)
> +
> +typedef struct S390ConfigState {
> +    SysBusDevice parent_obj;
> +    uint32_t fd;
> +} S390ConfigState;
> +
> +typedef struct S390ConfigClass {
> +    /*< private >*/
> +    SysBusDeviceClass parent_class;
> +    /*< public >*/
> +    int (*set_name)(S390ConfigState *config, char *name);
> +} S390ConfigClass;
> +
> +#ifdef CONFIG_KVM
> +void s390_config_dev_init(void);
> +S390ConfigState *get_config_state(void);
> +#define S390_MACHINE_NAME_SIZE sizeof(struct kvm_s390_attr_name)
> +#else
> +static inline void s390_config_dev_init(void) { }
> +static inline S390ConfigState *get_config_state(void)
> +{
> +    return NULL;
> +}
> +#define S390_MACHINE_NAME_SIZE 128
> +#endif
> +
> +#endif /* __KVM_S390_CONFIG_H */
> diff --git a/linux-headers/asm-s390/kvm.h b/linux-headers/asm-s390/kvm.h
> index cb4c1eb..432ffa5 100644
> --- a/linux-headers/asm-s390/kvm.h
> +++ b/linux-headers/asm-s390/kvm.h
> @@ -57,6 +57,17 @@ struct kvm_debug_exit_arch {
>  struct kvm_guest_debug_arch {
>  };
>
> +
> +
> +/* config device specific GROUPS */
> +
> +#define KVM_DEV_CONFIG_GROUP		0
> +#define KVM_DEV_CONFIG_NAME		0
> +
> +struct kvm_s390_attr_name {
> +	char name[128];
> +};
> +
>  #define KVM_SYNC_PREFIX (1UL << 0)
>  #define KVM_SYNC_GPRS   (1UL << 1)
>  #define KVM_SYNC_ACRS   (1UL << 2)
> diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
> index e27a4b3..59d1ec3 100644
> --- a/linux-headers/linux/kvm.h
> +++ b/linux-headers/linux/kvm.h
> @@ -921,6 +921,7 @@ struct kvm_device_attr {
>  #define   KVM_DEV_VFIO_GROUP_DEL			2
>  #define KVM_DEV_TYPE_ARM_VGIC_V2	5
>  #define KVM_DEV_TYPE_FLIC		6
> +#define KVM_DEV_TYPE_S390_CONFIG	7
>
>  /*
>   * ioctls for VM fds
> diff --git a/trace-events b/trace-events
> index 3df3f32..6ccd619 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1185,6 +1185,10 @@ css_adapter_interrupt(uint8_t isc) "CSS: adapter I/O interrupt (isc %x)"
>  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)"
>
> +# hw/s390x/config.c
> +config_no_device_api(int err) "config_dev: no Device Control API support %d"
> +config_create_device(int err) "config_dev: create device failed %d"
> +
>  # hw/intc/s390_flic.c
>  flic_create_device(int err) "flic: create device failed %d"
>  flic_no_device_api(int err) "flic: no Device Contral API support %d"
>