Re: [Qemu-devel] [PATCH 05/12] target-i386: push hot-plugged VCPU state to KVM and unstop it

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 27 Mar 2013 12:01:20 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il 21/03/2013 15:28, Igor Mammedov ha scritto:
> >  * synchronize CPU state to KVM
> >  * resume CPU, it makes CPU be able to handle interrupts in TCG mode
> >    and/or with user-space APIC.
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >  cpus.c                |   11 ++++++++---
> >  include/sysemu/cpus.h |    3 +++
> >  stubs/Makefile.objs   |    1 +
> >  stubs/resume_vcpu.c   |    6 ++++++
> >  target-i386/cpu.c     |    5 +++++
> >  5 files changed, 23 insertions(+), 3 deletions(-)
> >  create mode 100644 stubs/resume_vcpu.c
> > 
> > diff --git a/cpus.c b/cpus.c
> > index e919dd7..ae479bf 100644
> > --- a/cpus.c
> > +++ b/cpus.c
> > @@ -973,6 +973,13 @@ void pause_all_vcpus(void)
> >      }
> >  }
> >  
> > +void resume_vcpu(CPUState *cpu)
> > +{
> > +    cpu->stop = false;
> > +    cpu->stopped = false;
> > +    qemu_cpu_kick(cpu);
> > +}
> > +
> >  void resume_all_vcpus(void)
> >  {
> >      CPUArchState *penv = first_cpu;
> > @@ -980,9 +987,7 @@ void resume_all_vcpus(void)
> >      qemu_clock_enable(vm_clock, true);
> >      while (penv) {
> >          CPUState *pcpu = ENV_GET_CPU(penv);
> > -        pcpu->stop = false;
> > -        pcpu->stopped = false;
> > -        qemu_cpu_kick(pcpu);
> > +        resume_vcpu(pcpu);
> >          penv = penv->next_cpu;
> >      }
> >  }
> > diff --git a/include/sysemu/cpus.h b/include/sysemu/cpus.h
> > index 6502488..9437df5 100644
> > --- a/include/sysemu/cpus.h
> > +++ b/include/sysemu/cpus.h
> > @@ -1,11 +1,14 @@
> >  #ifndef QEMU_CPUS_H
> >  #define QEMU_CPUS_H
> >  
> > +#include "qom/cpu.h"
> > +
> >  /* cpus.c */
> >  void qemu_init_cpu_loop(void);
> >  void resume_all_vcpus(void);
> >  void pause_all_vcpus(void);
> >  void cpu_stop_current(void);
> > +void resume_vcpu(CPUState *cpu);
> >  
> >  void cpu_synchronize_all_states(void);
> >  void cpu_synchronize_all_post_reset(void);
> > diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
> > index 9c55b34..28fb4f8 100644
> > --- a/stubs/Makefile.objs
> > +++ b/stubs/Makefile.objs
> > @@ -23,3 +23,4 @@ stub-obj-y += sysbus.o
> >  stub-obj-y += vm-stop.o
> >  stub-obj-y += vmstate.o
> >  stub-obj-$(CONFIG_WIN32) += fd-register.o
> > +stub-obj-y += resume_vcpu.o
> > diff --git a/stubs/resume_vcpu.c b/stubs/resume_vcpu.c
> > new file mode 100644
> > index 0000000..383b71a
> > --- /dev/null
> > +++ b/stubs/resume_vcpu.c
> > @@ -0,0 +1,6 @@
> > +#include "qemu-common.h"
> > +#include "sysemu/cpus.h"
> > +
> > +void resume_vcpu(CPUState *cpu)
> > +{
> > +}
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index d03ff73..631bcd8 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -2260,6 +2260,11 @@ out:
> >          error_propagate(errp, local_err);
> >          return;
> >      }
> > +
> > +    if (dev->hotplugged) {
> > +        cpu_synchronize_post_init(env);
> > +        resume_vcpu(CPU(cpu));
> > +    }
> 
> I think the resume_vcpu should not be here, but in the superclass.

Then I should move following parts to superclass:

    if (dev->hotplugged) {
        cpu_synchronize_post_init(env);
        resume_vcpu(CPU(cpu));
    }

because in case of KVM we should make sure that CPU in sane state before
allowing CPU to become run-able.

> Paolo
> 
> >  }
> >  
> >  /* Enables contiguous-apic-ID mode, for compatibility */
> > 
> 
>