Re: [PATCH] revert part of 3db8b916e merge

[Avi Kivity <avi@redhat.com>]

Gleb Natapov wrote:
> kvm_*_mpstate() cannot be called from kvm_arch_*_registers()
> since kvm_arch_*_registers() sometimes called from io thread, but
> kvm_*_mpstate() can be called only by cpu thread.
>
>   

I really dislike vcpu functions to be called from outside the vcpu 
thread.  Who are the callers?

> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> diff --git a/qemu-kvm.c b/qemu-kvm.c
> index 68d3b92..7ed1e06 100644
> --- a/qemu-kvm.c
> +++ b/qemu-kvm.c
> @@ -1431,26 +1431,3 @@ void qemu_kvm_cpu_stop(CPUState *env)
>      if (kvm_enabled())
>          env->kvm_cpu_state.stopped = 1;
>  }
> -
> -void kvm_arch_get_registers(CPUState *env)
> -{
> -    kvm_save_registers(env);
> -    kvm_save_mpstate(env);
> -}
> -
> -void kvm_arch_put_registers(CPUState *env)
> -{
> -    kvm_load_registers(env);
> -    kvm_load_mpstate(env);
> -}
> -
> -
> -void cpu_synchronize_state(CPUState *env, int modified)
> -{
> -    if (kvm_enabled()) {
> -        if (modified)
> -            kvm_arch_put_registers(env);
> -        else
> -            kvm_arch_get_registers(env);
> -    }
> -}
> diff --git a/qemu-kvm.h b/qemu-kvm.h
> index 725589b..5d47e88 100644
> --- a/qemu-kvm.h
> +++ b/qemu-kvm.h
> @@ -216,10 +216,25 @@ int kvm_log_stop(target_phys_addr_t phys_addr, target_phys_addr_t len);
>  
>  static inline int kvm_sync_vcpus(void) { return 0; }
>  
> -void kvm_arch_get_registers(CPUState *env);
> -void kvm_arch_put_registers(CPUState *env);
> +static inline void kvm_arch_get_registers(CPUState *env)
> +{
> +    kvm_save_registers(env);
> +}
>  
> -void cpu_synchronize_state(CPUState *env, int modified);
> +static inline void kvm_arch_put_registers(CPUState *env)
> +{
> +    kvm_load_registers(env);
> +}
> +
> +static inline void cpu_synchronize_state(CPUState *env, int modified)
> +{
> +    if (kvm_enabled()) {
> +        if (modified)
> +            kvm_arch_put_registers(env);
> +        else
> +            kvm_arch_get_registers(env);
> +    }
> +}
>  
>  uint32_t kvm_arch_get_supported_cpuid(CPUState *env, uint32_t function,
>                                        int reg);
> diff --git a/target-i386/machine.c b/target-i386/machine.c
> index f280d3d..07df1e1 100644
> --- a/target-i386/machine.c
> +++ b/target-i386/machine.c
> @@ -32,7 +32,10 @@ void cpu_save(QEMUFile *f, void *opaque)
>      int32_t pending_irq;
>      int i, bit;
>  
> -    cpu_synchronize_state(env, 0);
> +    if (kvm_enabled()) {
> +        kvm_save_registers(env);
> +        kvm_save_mpstate(env);
> +    }
>  
>      for(i = 0; i < CPU_NB_REGS; i++)
>          qemu_put_betls(f, &env->regs[i]);
> --
> 			Gleb.
>   


-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.