Re: [Qemu-devel] [PATCH 2/2] s390x/kvm: implement floating-interrupt controller device

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 06/09/13 14:19, Jens Freimann wrote:
> This patch implements a floating-interrupt controller device (flic)
> which interacts with the s390 flic kvm_device.
> 
> It provides functionality to:
>     * clear all pending floating interrupts in the kernel at device reset
>     * inject/retrieve interrupts into the kernel (used for migration)
> 
> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>


> 
> ---
>  default-configs/s390x-softmmu.mak |   1 +
>  hw/intc/Makefile.objs             |   1 +
>  hw/intc/s390_flic.c               | 164 ++++++++++++++++++++++++++++++++++++++
>  hw/s390x/s390-virtio-ccw.c        |   8 +-
>  hw/s390x/s390-virtio.c            |   2 +
>  include/hw/s390x/s390_flic.h      |  31 +++++++
>  6 files changed, 206 insertions(+), 1 deletion(-)
> 
> diff --git a/default-configs/s390x-softmmu.mak b/default-configs/s390x-softmmu.mak
> index 81fbc68..d843dc0 100644
> --- a/default-configs/s390x-softmmu.mak
> +++ b/default-configs/s390x-softmmu.mak
> @@ -1,2 +1,3 @@
>  CONFIG_VIRTIO=y
>  CONFIG_SCLPCONSOLE=y
> +CONFIG_S390_FLIC=$(CONFIG_KVM)
> diff --git a/hw/intc/Makefile.objs b/hw/intc/Makefile.objs
> index 2851eed..b2305aa 100644
> --- a/hw/intc/Makefile.objs
> +++ b/hw/intc/Makefile.objs
> @@ -23,3 +23,4 @@ obj-$(CONFIG_OMAP) += omap_intc.o
>  obj-$(CONFIG_OPENPIC_KVM) += openpic_kvm.o
>  obj-$(CONFIG_SH4) += sh_intc.o
>  obj-$(CONFIG_XICS) += xics.o
> +obj-$(CONFIG_S390_FLIC) += s390_flic.o
> diff --git a/hw/intc/s390_flic.c b/hw/intc/s390_flic.c
> new file mode 100644
> index 0000000..9dfaafa
> --- /dev/null
> +++ b/hw/intc/s390_flic.c
> @@ -0,0 +1,164 @@
> +/*
> + * QEMU S390x KVM floating interrupt controller (flic)
> + *
> + * Copyright 2013 IBM Corp.
> + * Author(s): Jens Freimann <jfrei@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/sysbus.h"
> +#include "sysemu/kvm.h"
> +#include "migration/qemu-file.h"
> +#include "hw/s390x/s390_flic.h"
> +
> +void s390_flic_init(void)
> +{
> +    DeviceState *dev;
> +
> +    if (kvm_enabled()) {
> +        dev = qdev_create(NULL, "s390-flic");
> +        object_property_add_child(qdev_get_machine(), "s390-flic",
> +                                  OBJECT(dev), NULL);
> +        qdev_init_nofail(dev);
> +    }
> +}
> +
> +static int flic_dequeue_irq(QEMUFile *f, struct kvm_s390_irq *s390irq,
> +                            KVMS390FLICState *flic)
> +{
> +    struct kvm_device_attr attr;
> +    int rc;
> +
> +    attr.group = KVM_DEV_FLIC_DEQUEUE;
> +    attr.addr = (uint64_t) s390irq;
> +
> +    rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);
> +
> +    return rc ? -errno : 0;
> +}
> +
> +static int flic_enqueue_irq(QEMUFile *f, struct kvm_s390_irq *s390irq,
> +                            KVMS390FLICState *flic)
> +{
> +    int rc;
> +    struct kvm_device_attr attr;
> +
> +    attr.group = KVM_DEV_FLIC_ENQUEUE;
> +    attr.addr = (uint64_t) s390irq;
> +
> +    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
> +
> +    return rc ? -errno : 0;
> +}
> +
> +/* Save pending floating interrupts. */
> +static void kvm_floating_interrupt_save(QEMUFile *f, void *opaque)
> +{
> +    struct kvm_s390_irq s390irq = {0};
> +    int r = 0;
> +
> +    while (!r) {
> +        r = flic_dequeue_irq(f, &s390irq, opaque);
> +        if (r == -ENODATA) {
> +            /* At end of list: write special marker */
> +            memset(&s390irq, 0, sizeof(s390irq));
> +            s390irq.type = 0xffffffff;
> +        }
> +        qemu_put_buffer(f, (uint8_t *) &s390irq, sizeof(s390irq));
> +    }
> +}
> +
> +/* Load pending floating interrupts. */
> +static int kvm_floating_interrupt_load(QEMUFile *f, void *opaque, int version_id)
> +{
> +    int r = 0;
> +    struct kvm_s390_irq s390irq = {0};
> +
> +    while (!r) {
> +        qemu_get_buffer(f, (uint8_t *) &s390irq, sizeof(s390irq));
> +        /* Watch for marker indicating end of list */
> +        if (s390irq.type == 0xffffffff) {
> +            return 0;
> +        }
> +        r = flic_enqueue_irq(f, &s390irq, (struct KVMS390FLICState *) opaque);
> +    }
> +
> +    return r;
> +}
> +
> +static void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
> +{
> +    KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
> +    struct kvm_create_device cd = {0};
> +    int ret;
> +
> +    flic_state->fd = -1;
> +    if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
> +        return;
> +    }
> +
> +    cd.type = KVM_DEV_TYPE_FLIC;
> +    ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
> +    if (ret < 0) {
> +        perror("flic: couldn't create kvm_device");
> +        return;
> +    }
> +    flic_state->fd = cd.fd;
> +
> +    /* Register savevm handler for floating interrupts */
> +    register_savevm(NULL, "floatingint", 0, 1, kvm_floating_interrupt_save,
> +                    kvm_floating_interrupt_load, (void *) flic_state);
> +}
> +
> +static void kvm_s390_flic_unrealize(DeviceState *dev, Error **errp)
> +{
> +    KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
> +
> +    unregister_savevm(DEVICE(flic_state), "floatingint", flic_state);
> +}
> +
> +static void kvm_s390_flic_reset(DeviceState *dev)
> +{
> +    KVMS390FLICState *flic = KVM_S390_FLIC(dev);
> +    struct kvm_device_attr attr;
> +    int rc = 0;
> +
> +    if (flic->fd == -1) {
> +        return;
> +    }
> +
> +    attr.group = KVM_DEV_FLIC_CLEAR_IRQS;
> +
> +    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
> +    if (rc) {
> +        perror("flic: reset failed");
> +    }
> +}
> +
> +static void kvm_s390_flic_class_init(ObjectClass *oc, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +
> +    dc->realize = kvm_s390_flic_realize;
> +    dc->unrealize = kvm_s390_flic_unrealize;
> +    dc->reset = kvm_s390_flic_reset;
> +    dc->no_user = 1;
> +}
> +
> +static const TypeInfo kvm_s390_flic_info = {
> +    .name          = TYPE_KVM_S390_FLIC,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(KVMS390FLICState),
> +    .class_init    = kvm_s390_flic_class_init,
> +};
> +
> +static void kvm_s390_flic_register_types(void)
> +{
> +    type_register_static(&kvm_s390_flic_info);
> +}
> +
> +type_init(kvm_s390_flic_register_types)
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 733d988..0d4f6ae 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -13,13 +13,14 @@
>  #include "exec/address-spaces.h"
>  #include "s390-virtio.h"
>  #include "hw/s390x/sclp.h"
> +#include "hw/s390x/s390_flic.h"
>  #include "ioinst.h"
>  #include "css.h"
>  #include "virtio-ccw.h"
> 
>  void io_subsystem_reset(void)
>  {
> -    DeviceState *css, *sclp;
> +    DeviceState *css, *sclp, *flic;
> 
>      css = DEVICE(object_resolve_path_type("", "virtual-css-bridge", NULL));
>      if (css) {
> @@ -30,6 +31,10 @@ void io_subsystem_reset(void)
>      if (sclp) {
>          qdev_reset_all(sclp);
>      }
> +    flic = DEVICE(object_resolve_path_type("", "s390-flic", NULL));
> +    if (flic) {
> +        qdev_reset_all(flic);
> +    }
>  }
> 
>  static int virtio_ccw_hcall_notify(const uint64_t *args)
> @@ -99,6 +104,7 @@ static void ccw_init(QEMUMachineInitArgs *args)
>      s390_sclp_init();
>      s390_init_ipl_dev(args->kernel_filename, args->kernel_cmdline,
>                        args->initrd_filename, "s390-ccw.img");
> +    s390_flic_init();
> 
>      /* register hypercalls */
>      virtio_ccw_register_hcalls();
> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
> index 7adf92a..5b54af7 100644
> --- a/hw/s390x/s390-virtio.c
> +++ b/hw/s390x/s390-virtio.c
> @@ -36,6 +36,7 @@
> 
>  #include "hw/s390x/s390-virtio-bus.h"
>  #include "hw/s390x/sclp.h"
> +#include "hw/s390x/s390_flic.h"
>  #include "hw/s390x/s390-virtio.h"
> 
>  //#define DEBUG_S390
> @@ -251,6 +252,7 @@ static void s390_init(QEMUMachineInitArgs *args)
>      s390_sclp_init();
>      s390_init_ipl_dev(args->kernel_filename, args->kernel_cmdline,
>                        args->initrd_filename, ZIPL_FILENAME);
> +    s390_flic_init();
> 
>      /* register hypercalls */
>      s390_virtio_register_hcalls();
> diff --git a/include/hw/s390x/s390_flic.h b/include/hw/s390x/s390_flic.h
> new file mode 100644
> index 0000000..2b83f35
> --- /dev/null
> +++ b/include/hw/s390x/s390_flic.h
> @@ -0,0 +1,31 @@
> +/*
> + * QEMU S390x KVM floating interrupt controller (flic)
> + *
> + * Copyright 2013 IBM Corp.
> + * Author(s): Jens Freimann <jfrei@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_FLIC_H
> +#define __KVM_S390_FLIC_H
> +
> +#define TYPE_KVM_S390_FLIC "s390-flic"
> +#define KVM_S390_FLIC(obj) \
> +    OBJECT_CHECK(KVMS390FLICState, (obj), TYPE_KVM_S390_FLIC)
> +
> +typedef struct KVMS390FLICState {
> +    DeviceState parent_obj;
> +
> +    uint32_t fd;
> +} KVMS390FLICState;
> +
> +#ifdef CONFIG_KVM
> +void s390_flic_init(void);
> +#else
> +static inline void s390_flic_init(void) { }
> +#endif
> +
> +#endif /* __KVM_S390_FLIC_H */
>