Re: [Qemu-devel] [PATCH] mips: implement qmp query-cpu-definitions command

[Pavel Dovgalyuk]

> From: Aleksandar Markovic [mailto:address@hidden
> > From: Pavel Dovgalyuk [mailto:address@hidden
> >
> > This patch enables QMP-based querying of the available CPU types for MIPS
> > and MIPS64 platforms.
> >
> > Signed-off-by: Pavel Dovgalyuk <address@hidden>
> > ---
> >  monitor.c            |    2 +-
> >  target/mips/helper.c |   33 +++++++++++++++++++++++++++++++++
> >  2 files changed, 34 insertions(+), 1 deletion(-)
> >
> 
> Hello, Pavel,
> 
> Thanks for involving in this area!
> 
> I have just a couple of question:
> 
> 1) What are the effects of these two patches on the end user?

This patch make qmp query-cpu-definitions available for the MIPS users.
This command allows requesting possible CPU models with QMP.

> 2) What is the context of these patches? Do you intend to send more related 
> patches in the
> future? Are these patches preconditions for some other not yet implemented 
> features?

Not yet.
We are developing GUI for virtual machine management and debugging
with record-replay feature: https://github.com/ispras/qemu-gui
Therefore we need to request possible CPU and hardware options.

> 3) Why is only target MIPS included? Do other targets need similar 
> improvements?

We use MIPS in our projects. Some other targets need similar improvements, but 
we do
not focus on them right now.

Pavel Dovgalyuk

> 
> Thanks,
> Aleksandar
> 
> 
> > diff --git a/monitor.c b/monitor.c
> > index c09fa63940..25d3b141ad 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -1165,7 +1165,7 @@ static void qmp_unregister_commands_hack(void)
> >      qmp_unregister_command(&qmp_commands, "query-cpu-model-comparison");
> >  #endif
> >  #if !defined(TARGET_PPC) && !defined(TARGET_ARM) && !defined(TARGET_I386) \
> > -    && !defined(TARGET_S390X)
> > +    && !defined(TARGET_S390X) && !defined(TARGET_MIPS)
> >      qmp_unregister_command(&qmp_commands, "query-cpu-definitions");
> >  #endif
> >  }
> > diff --git a/target/mips/helper.c b/target/mips/helper.c
> > index 8988452dbd..c84d056c09 100644
> > --- a/target/mips/helper.c
> > +++ b/target/mips/helper.c
> > @@ -24,6 +24,7 @@
> >  #include "exec/cpu_ldst.h"
> >  #include "exec/log.h"
> >  #include "hw/mips/cpudevs.h"
> > +#include "sysemu/arch_init.h"
> >
> >  enum {
> >      TLBRET_XI = -6,
> > @@ -1472,3 +1473,35 @@ void QEMU_NORETURN 
> > do_raise_exception_err(CPUMIPSState *env,
> >
> >      cpu_loop_exit_restore(cs, pc);
> >  }
> > +
> > +static void mips_cpu_add_definition(gpointer data, gpointer user_data)
> > +{
> > +    ObjectClass *oc = data;
> > +    CpuDefinitionInfoList **cpu_list = user_data;
> > +    CpuDefinitionInfoList *entry;
> > +    CpuDefinitionInfo *info;
> > +    const char *typename;
> > +
> > +    typename = object_class_get_name(oc);
> > +    info = g_malloc0(sizeof(*info));
> > +    info->name = g_strndup(typename,
> > +                           strlen(typename) - strlen("-" TYPE_MIPS_CPU));
> > +    info->q_typename = g_strdup(typename);
> > +
> > +    entry = g_malloc0(sizeof(*entry));
> > +    entry->value = info;
> > +    entry->next = *cpu_list;
> > +    *cpu_list = entry;
> > +}
> > +
> > +CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp)
> > +{
> > +    CpuDefinitionInfoList *cpu_list = NULL;
> > +    GSList *list;
> > +
> > +    list = object_class_get_list(TYPE_MIPS_CPU, false);
> > +    g_slist_foreach(list, mips_cpu_add_definition, &cpu_list);
> > +    g_slist_free(list);
> > +
> > +    return cpu_list;
> > +}
> 
>