Re: [Qemu-devel] [PATCH v6 2/4] target-s390x: Migrate to new NMI interface

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 06/12/2014 04:31 PM, Cornelia Huck wrote:
> On Thu, 12 Jun 2014 03:03:01 +1000
> Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
> 
>> This implements an NMI interface for s390 machine.
>>
>> This removes #ifdef s390 branch in qmp_inject_nmi so new s390's
>> nmi_monitor_handler() callback is going to be used for NMI.
>>
>> Since nmi_monitor_handler()-calling code is platform independent,
>> CPUState::cpu_index is used instead of S390CPU::env.cpu_num.
>> There should not be any change in behaviour as both @cpu_index and
>> @cpu_num are global CPU numbers.
>>
>> Also, s390_cpu_restart() takes care of preforming operations in
>> the specific CPU thread so no extra measure is required here either.
>>
>> Since the only error s390_cpu_restart() can return is ENOSYS, convert
>> it to QERR_UNSUPPORTED.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>> Changes:
>> v6:
>> * supported NMI interface
>>
>> v5:
>> * added ENOSYS -> QERR_UNSUPPORTED, qapi/qmp/qerror.h was added for this
>>
>> v4:
>> * s/\<nmi\>/nmi_monitor_handler/
>>
>> v3:
>> * now contains both old code removal and new code insertion, easier to
>> track changes
>>
>> ---
>> Is there any good reason to have @cpu_num in addition to @cpu_index?
>> Just asking :)
>> ---
>>  cpus.c                 | 14 --------------
>>  hw/s390x/s390-virtio.c | 31 +++++++++++++++++++++++++++++++
>>  target-s390x/cpu.c     |  1 +
>>  3 files changed, 32 insertions(+), 14 deletions(-)
>>
> 
>> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
>> index 93c7ace..9c5b7b2 100644
>> --- a/hw/s390x/s390-virtio.c
>> +++ b/hw/s390x/s390-virtio.c
>> @@ -38,6 +38,7 @@
>>  #include "hw/s390x/sclp.h"
>>  #include "hw/s390x/s390_flic.h"
>>  #include "hw/s390x/s390-virtio.h"
>> +#include "hw/nmi.h"
>>
>>  //#define DEBUG_S390
>>
>> @@ -51,6 +52,7 @@
>>
>>  #define MAX_BLK_DEVS                    10
>>  #define ZIPL_FILENAME                   "s390-zipl.rom"
>> +#define TYPE_NMI_S390                   "s390_nmi"
> 
> I'd prefer "s390-nmi" instead.
>
>>
>>  static VirtIOS390Bus *s390_bus;
>>  static S390CPU **ipi_states;
>> @@ -277,6 +279,9 @@ static void s390_init(MachineState *machine)
>>
>>      /* Create VirtIO network adapters */
>>      s390_create_virtio_net((BusState *)s390_bus, "virtio-net-s390");
>> +
>> +    object_property_add_child(OBJECT(machine), "nmi",
>> +                              object_new(TYPE_NMI_S390), NULL);
> 
> This only adds the nmi interface to the old s390-virtio machine; we
> want this for the s390-virtio-ccw machine as well.
> 
>>  }
>>
>>  static QEMUMachine s390_machine = {
>> @@ -295,8 +300,34 @@ static QEMUMachine s390_machine = {
>>      .is_default = 1,
>>  };
>>
>> +static void s390_nmi(NMI *n, int cpu_index, Error **errp)
>> +{
>> +    CPUState *cs = qemu_get_cpu(cpu_index);
>> +
>> +    if (s390_cpu_restart(S390_CPU(cs))) {
>> +        error_set(errp, QERR_UNSUPPORTED);
>> +    }
>> +}
>> +
>> +static void s390_nmi_class_init(ObjectClass *oc, void *data)
>> +{
>> +    NMIClass *nc = NMI_CLASS(oc);
>> +    nc->nmi_monitor_handler = s390_nmi;
>> +}
>> +
>> +static const TypeInfo s390_nmi_info = {
>> +    .name          = TYPE_NMI_S390,
>> +    .parent        = TYPE_OBJECT,
>> +    .class_init    = s390_nmi_class_init,
>> +    .interfaces = (InterfaceInfo[]) {
>> +        { TYPE_NMI },
>> +        { }
>> +    },
>> +};
>> +
>>  static void s390_machine_init(void)
>>  {
>> +    type_register_static(&s390_nmi_info);
> 
> s390-virtio-ccw needs this as well.
> 
>>      qemu_register_machine(&s390_machine);
>>  }
> 
> The best way would probably be to put all nmi-related things into a new
> file that registers the nmi type and provides an s390_register_nmi()
> helper.


I pushed some version to git@github.com:aik/qemu.git , branch nmi-v7
Please have a look and give it a go - I do not have s390 kernel/images
handy. Thanks!

It does not look like we really need a new file for NMI now.
Also, should I put it under #ifdef CONFIG_USER_ONLY on s390?


>>
>> diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
>> index c3082b7..15142ff 100644
>> --- a/target-s390x/cpu.c
>> +++ b/target-s390x/cpu.c
>> @@ -27,6 +27,7 @@
>>  #include "qemu-common.h"
>>  #include "qemu/timer.h"
>>  #include "hw/hw.h"
>> +#include "qapi/qmp/qerror.h"
> 
> Leftover?

yes :(


>>  #ifndef CONFIG_USER_ONLY
>>  #include "sysemu/arch_init.h"
>>  #endif
> 


-- 
Alexey