[Qemu-devel] Re: [PATCH 03/21] qemu-kvm: Clean up register access API

[Gleb Natapov]

On Tue, Feb 02, 2010 at 09:18:49AM +0100, Jan Kiszka wrote:
> qemu-kvm's functios for accessing the VCPU registers are
> kvm_arch_load/save_regs. Use them directly instead of going through
> various wrappers. Specifically, we do not need on_vcpu wrapping as all
> users either already run in the related thread or call while the vm is
> stopped.
> 
Can we put check for that into those functions just to be sure.
Something like:
        assert(!vm_stopped && env->thread_id != pthread_id())

> Signed-off-by: Jan Kiszka <address@hidden>
> ---
>  qemu-kvm.c            |   37 +++----------------------------------
>  qemu-kvm.h            |   11 -----------
>  target-ia64/machine.c |    4 ++--
>  3 files changed, 5 insertions(+), 47 deletions(-)
> 
> diff --git a/qemu-kvm.c b/qemu-kvm.c
> index a305907..97c098c 100644
> --- a/qemu-kvm.c
> +++ b/qemu-kvm.c
> @@ -862,7 +862,7 @@ int pre_kvm_run(kvm_context_t kvm, CPUState *env)
>      kvm_arch_pre_run(env, env->kvm_run);
>  
>      if (env->kvm_cpu_state.regs_modified) {
> -        kvm_arch_put_registers(env);
> +        kvm_arch_load_regs(env);
>          env->kvm_cpu_state.regs_modified = 0;
>      }
>  
> @@ -1532,16 +1532,11 @@ static void on_vcpu(CPUState *env, void (*func)(void 
> *data), void *data)
>          qemu_cond_wait(&qemu_work_cond);
>  }
>  
> -void kvm_arch_get_registers(CPUState *env)
> -{
> -     kvm_arch_save_regs(env);
> -}
> -
>  static void do_kvm_cpu_synchronize_state(void *_env)
>  {
>      CPUState *env = _env;
>      if (!env->kvm_cpu_state.regs_modified) {
> -        kvm_arch_get_registers(env);
> +        kvm_arch_save_regs(env);
>          env->kvm_cpu_state.regs_modified = 1;
>      }
>  }
> @@ -1584,32 +1579,6 @@ void kvm_update_interrupt_request(CPUState *env)
>      }
>  }
>  
> -static void kvm_do_load_registers(void *_env)
> -{
> -    CPUState *env = _env;
> -
> -    kvm_arch_load_regs(env);
> -}
> -
> -void kvm_load_registers(CPUState *env)
> -{
> -    if (kvm_enabled() && qemu_system_ready)
> -        on_vcpu(env, kvm_do_load_registers, env);
> -}
> -
> -static void kvm_do_save_registers(void *_env)
> -{
> -    CPUState *env = _env;
> -
> -    kvm_arch_save_regs(env);
> -}
> -
> -void kvm_save_registers(CPUState *env)
> -{
> -    if (kvm_enabled())
> -        on_vcpu(env, kvm_do_save_registers, env);
> -}
> -
>  static void kvm_do_load_mpstate(void *_env)
>  {
>      CPUState *env = _env;
> @@ -2379,7 +2348,7 @@ static void kvm_invoke_set_guest_debug(void *data)
>      struct kvm_set_guest_debug_data *dbg_data = data;
>  
>      if (cpu_single_env->kvm_cpu_state.regs_modified) {
> -        kvm_arch_put_registers(cpu_single_env);
> +        kvm_arch_save_regs(cpu_single_env);
>          cpu_single_env->kvm_cpu_state.regs_modified = 0;
>      }
>      dbg_data->err =
> diff --git a/qemu-kvm.h b/qemu-kvm.h
> index 6b3e5a1..1354227 100644
> --- a/qemu-kvm.h
> +++ b/qemu-kvm.h
> @@ -902,8 +902,6 @@ int kvm_main_loop(void);
>  int kvm_init_ap(void);
>  #ifndef QEMU_KVM_NO_CPU
>  int kvm_vcpu_inited(CPUState *env);
> -void kvm_load_registers(CPUState *env);
> -void kvm_save_registers(CPUState *env);
>  void kvm_load_mpstate(CPUState *env);
>  void kvm_save_mpstate(CPUState *env);
>  int kvm_cpu_exec(CPUState *env);
> @@ -1068,8 +1066,6 @@ void kvm_load_tsc(CPUState *env);
>  #ifdef TARGET_I386
>  #define qemu_kvm_has_pit_state2() (0)
>  #endif
> -#define kvm_load_registers(env) do {} while(0)
> -#define kvm_save_registers(env) do {} while(0)
>  #define kvm_save_mpstate(env)   do {} while(0)
>  #define qemu_kvm_cpu_stop(env) do {} while(0)
>  static inline void kvm_init_vcpu(CPUState *env)
> @@ -1098,13 +1094,6 @@ static inline int kvm_sync_vcpus(void)
>  }
>  
>  #ifndef QEMU_KVM_NO_CPU
> -void kvm_arch_get_registers(CPUState *env);
> -
> -static inline void kvm_arch_put_registers(CPUState *env)
> -{
> -    kvm_load_registers(env);
> -}
> -
>  void kvm_cpu_synchronize_state(CPUState *env);
>  
>  static inline void cpu_synchronize_state(CPUState *env)
> diff --git a/target-ia64/machine.c b/target-ia64/machine.c
> index 70ef379..7d29575 100644
> --- a/target-ia64/machine.c
> +++ b/target-ia64/machine.c
> @@ -9,7 +9,7 @@ void cpu_save(QEMUFile *f, void *opaque)
>      CPUState *env = opaque;
>  
>      if (kvm_enabled()) {
> -        kvm_save_registers(env);
> +        kvm_arch_save_regs(env);
>          kvm_arch_save_mpstate(env);
>      }
>  }
> @@ -19,7 +19,7 @@ int cpu_load(QEMUFile *f, void *opaque, int version_id)
>      CPUState *env = opaque;
>  
>      if (kvm_enabled()) {
> -        kvm_load_registers(env);
> +        kvm_arch_load_regs(env);
>          kvm_arch_load_mpstate(env);
>      }
>      return 0;
> -- 
> 1.6.0.2
> 
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--
                        Gleb.