Re: [Qemu-devel] [PATCH v3 1/4] cpus: Define NMI callback

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 06/10/2014 11:39 PM, Luiz Capitulino wrote:
> On Wed,  4 Jun 2014 18:08:47 +1000
> Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
> 
>> This introduces an NMI (non maskable interrupt) callback per CPU class
>> which QMP's "nmi" command may use to issue NMI on a CPU.
>>
>> This adds support for it in qmp_inject_nmi(). Since no architecture
>> supports it at the moment, there is no change in behaviour.
>>
>> This changes inject-nmi command description for HMP and QMP.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>> Changes:
>> v3:
>> * actual nmi() enablement moved from last patch to first patch
>> * changed description for QMP command too
>> ---
>>  cpus.c            | 11 ++++++++++-
>>  hmp-commands.hx   |  6 ++----
>>  include/qom/cpu.h |  1 +
>>  qapi-schema.json  |  4 +---
>>  qmp-commands.hx   |  3 +--
>>  5 files changed, 15 insertions(+), 10 deletions(-)
>>
>> diff --git a/cpus.c b/cpus.c
>> index dd7ac13..a000bd8 100644
>> --- a/cpus.c
>> +++ b/cpus.c
>> @@ -1495,6 +1495,15 @@ void qmp_inject_nmi(Error **errp)
>>          }
>>      }
>>  #else
>> -    error_set(errp, QERR_UNSUPPORTED);
>> +    CPUState *cs = qemu_get_cpu(monitor_get_cpu_index());
>> +    CPUClass *cc = CPU_GET_CLASS(cs);
>> +    int ret = -1;
>> +
>> +    if (cs && cc->nmi) {
>> +        ret = cc->nmi(cs);
>> +    }
>> +    if (ret) {
>> +        error_set(errp, QERR_UNSUPPORTED);
>> +    }
>>  #endif
>>  }
>> diff --git a/hmp-commands.hx b/hmp-commands.hx
>> index 2e462c0..e97b5ec 100644
>> --- a/hmp-commands.hx
>> +++ b/hmp-commands.hx
>> @@ -830,19 +830,17 @@ The values that can be specified here depend on the machine type, but are
>>  the same that can be specified in the @code{-boot} command line option.
>>  ETEXI
>>  
>> -#if defined(TARGET_I386) || defined(TARGET_S390X)
>>      {
>>          .name       = "nmi",
>>          .args_type  = "",
>>          .params     = "",
>> -        .help       = "inject an NMI on all guest's CPUs",
>> +        .help       = "inject an NMI on the given guest's CPU",
>>          .mhandler.cmd = hmp_inject_nmi,
>>      },
>> -#endif
>>  STEXI
>>  @item nmi @var{cpu}
>>  @findex nmi
>> -Inject an NMI (x86) or RESTART (s390x) on the given CPU.
>> +Inject an NMI on the given CPU.
>>  
>>  ETEXI
>>  
>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>> index df977c8..b34f23b 100644
>> --- a/include/qom/cpu.h
>> +++ b/include/qom/cpu.h
>> @@ -108,6 +108,7 @@ typedef struct CPUClass {
>>      void (*parse_features)(CPUState *cpu, char *str, Error **errp);
>>  
>>      void (*reset)(CPUState *cpu);
>> +    int (*nmi)(CPUState *cs);
>>      int reset_dump_flags;
>>      bool (*has_work)(CPUState *cpu);
>>      void (*do_interrupt)(CPUState *cpu);
>> diff --git a/qapi-schema.json b/qapi-schema.json
>> index 7bc33ea..dcf6642 100644
>> --- a/qapi-schema.json
>> +++ b/qapi-schema.json
>> @@ -1748,13 +1748,11 @@
>>  ##
>>  # @inject-nmi:
>>  #
>> -# Injects an Non-Maskable Interrupt into all guest's VCPUs.
>> +# Injects an Non-Maskable Interrupt into the given guest's VCPU.
> 
> QMP doesn't have the concept of "current monitored CPU" you talk in the
> intro email. In QMP you have to specify the CPU. You have to choices:


If QMP does not have such a concept, then how does it work now?


> 
>  - Add a new command that takes a CPU parameter (seems the best to me, as
>    people were asking for a different command anyways)
> 
>  - Add an optional parameter to inject-nmi. When the CPU parameter is
>    not specified, the command sends the NMI to all CPUs
> 
> Eric, any thoughts?
> 
>>  #
>>  # Returns:  If successful, nothing
>>  #
>>  # Since:  0.14.0
>> -#
>> -# Notes: Only x86 Virtual Machines support this command.
>>  ##
>>  { 'command': 'inject-nmi' }
>>  
>> diff --git a/qmp-commands.hx b/qmp-commands.hx
>> index d8aa4ed..553375b 100644
>> --- a/qmp-commands.hx
>> +++ b/qmp-commands.hx
>> @@ -477,7 +477,7 @@ SQMP
>>  inject-nmi
>>  ----------
>>  
>> -Inject an NMI on guest's CPUs.
>> +Inject an NMI on the given guest's CPU.
>>  
>>  Arguments: None.
>>  
>> @@ -487,7 +487,6 @@ Example:
>>  <- { "return": {} }
>>  
>>  Note: inject-nmi fails when the guest doesn't support injecting.
>> -      Currently, only x86 (NMI) and s390x (RESTART) guests do.
>>  
>>  EQMP
>>  
> 


-- 
Alexey