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Re: [Qemu-devel] [PATCH for-2.0] cpu: do not use QOM casts in ENV_GET_CP
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From: |
Laurent Desnogues |
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Subject: |
Re: [Qemu-devel] [PATCH for-2.0] cpu: do not use QOM casts in ENV_GET_CPU |
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Date: |
Fri, 28 Mar 2014 14:55:46 +0100 |
On Wed, Mar 26, 2014 at 2:42 PM, Paolo Bonzini <address@hidden> wrote:
> QOM casts are only typesafe inasmuch as we know that the argument is
> a QOM object. If it is not, the accesses to fields in Object can
> access invalid memory and thus cause a segfault.
>
> Using a QOM cast in ENV_GET_CPU is useless and harmful. Useless,
> because the cast is applied to the result of container_of, which is
> type safe. So the QOM cast is nothing but typesafety theater.
> Harmful, because ENV_GET_CPU *is* used in hot paths especially
> now that, in 2.0, the movement of fields from CPU_COMMON to
> CPUState was completed.
I tested the ARM part of the patch; on my test (kernel boot + run of
Sunspider with Google V8), I get the following user time results:
(average of 5 runs):
- before: 17.8s
- with your patch: 17s
configure was run with no option.
Tested-by: Laurent Desnogues <address@hidden>
Thanks,
Laurent
> Reported-by: Laurent Desnogues <address@hidden>
> Cc: Andreas Faerber <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
> target-alpha/cpu-qom.h | 2 +-
> target-arm/cpu-qom.h | 2 +-
> target-cris/cpu-qom.h | 2 +-
> target-i386/cpu-qom.h | 2 +-
> target-lm32/cpu-qom.h | 2 +-
> target-m68k/cpu-qom.h | 2 +-
> target-microblaze/cpu-qom.h | 2 +-
> target-mips/cpu-qom.h | 2 +-
> target-ppc/cpu-qom.h | 2 +-
> target-s390x/cpu-qom.h | 2 +-
> target-sh4/cpu-qom.h | 2 +-
> target-sparc/cpu-qom.h | 2 +-
> target-unicore32/cpu-qom.h | 2 +-
> target-xtensa/cpu-qom.h | 2 +-
> 14 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/target-alpha/cpu-qom.h b/target-alpha/cpu-qom.h
> index 198f1b1..47b3130 100644
> --- a/target-alpha/cpu-qom.h
> +++ b/target-alpha/cpu-qom.h
> @@ -70,7 +70,7 @@ static inline AlphaCPU *alpha_env_get_cpu(CPUAlphaState
> *env)
> return container_of(env, AlphaCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(alpha_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)alpha_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(AlphaCPU, env)
>
> diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
> index 00234e1..34506b5 100644
> --- a/target-arm/cpu-qom.h
> +++ b/target-arm/cpu-qom.h
> @@ -169,7 +169,7 @@ static inline ARMCPU *arm_env_get_cpu(CPUARMState *env)
> return container_of(env, ARMCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(arm_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)arm_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(ARMCPU, env)
>
> diff --git a/target-cris/cpu-qom.h b/target-cris/cpu-qom.h
> index 7559366..be7a3e4 100644
> --- a/target-cris/cpu-qom.h
> +++ b/target-cris/cpu-qom.h
> @@ -69,7 +69,7 @@ static inline CRISCPU *cris_env_get_cpu(CPUCRISState *env)
> return container_of(env, CRISCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(cris_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)cris_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(CRISCPU, env)
>
> diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
> index e9b3d57..dc68188 100644
> --- a/target-i386/cpu-qom.h
> +++ b/target-i386/cpu-qom.h
> @@ -111,7 +111,7 @@ static inline X86CPU *x86_env_get_cpu(CPUX86State *env)
> return container_of(env, X86CPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(x86_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)x86_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(X86CPU, env)
>
> diff --git a/target-lm32/cpu-qom.h b/target-lm32/cpu-qom.h
> index 9f15093..47b3d31 100644
> --- a/target-lm32/cpu-qom.h
> +++ b/target-lm32/cpu-qom.h
> @@ -73,7 +73,7 @@ static inline LM32CPU *lm32_env_get_cpu(CPULM32State *env)
> return container_of(env, LM32CPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(lm32_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)lm32_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(LM32CPU, env)
>
> diff --git a/target-m68k/cpu-qom.h b/target-m68k/cpu-qom.h
> index 7f388ed..8410df8 100644
> --- a/target-m68k/cpu-qom.h
> +++ b/target-m68k/cpu-qom.h
> @@ -66,7 +66,7 @@ static inline M68kCPU *m68k_env_get_cpu(CPUM68KState *env)
> return container_of(env, M68kCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(m68k_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)m68k_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(M68kCPU, env)
>
> diff --git a/target-microblaze/cpu-qom.h b/target-microblaze/cpu-qom.h
> index 35a12b4..0c9988a 100644
> --- a/target-microblaze/cpu-qom.h
> +++ b/target-microblaze/cpu-qom.h
> @@ -67,7 +67,7 @@ static inline MicroBlazeCPU *mb_env_get_cpu(CPUMBState *env)
> return container_of(env, MicroBlazeCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(mb_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)mb_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(MicroBlazeCPU, env)
>
> diff --git a/target-mips/cpu-qom.h b/target-mips/cpu-qom.h
> index 8877f81..31ed2f2 100644
> --- a/target-mips/cpu-qom.h
> +++ b/target-mips/cpu-qom.h
> @@ -70,7 +70,7 @@ static inline MIPSCPU *mips_env_get_cpu(CPUMIPSState *env)
> return container_of(env, MIPSCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(mips_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)mips_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(MIPSCPU, env)
>
> diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h
> index 47dc8e6..75704fd 100644
> --- a/target-ppc/cpu-qom.h
> +++ b/target-ppc/cpu-qom.h
> @@ -99,7 +99,7 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
> return container_of(env, PowerPCCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(ppc_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)ppc_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(PowerPCCPU, env)
>
> diff --git a/target-s390x/cpu-qom.h b/target-s390x/cpu-qom.h
> index ac0460e..0f90d0b 100644
> --- a/target-s390x/cpu-qom.h
> +++ b/target-s390x/cpu-qom.h
> @@ -73,7 +73,7 @@ static inline S390CPU *s390_env_get_cpu(CPUS390XState *env)
> return container_of(env, S390CPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(s390_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)s390_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(S390CPU, env)
>
> diff --git a/target-sh4/cpu-qom.h b/target-sh4/cpu-qom.h
> index c04e786..4f44b04 100644
> --- a/target-sh4/cpu-qom.h
> +++ b/target-sh4/cpu-qom.h
> @@ -79,7 +79,7 @@ static inline SuperHCPU *sh_env_get_cpu(CPUSH4State *env)
> return container_of(env, SuperHCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(sh_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)sh_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(SuperHCPU, env)
>
> diff --git a/target-sparc/cpu-qom.h b/target-sparc/cpu-qom.h
> index 8e3e0de..8e4a8b5 100644
> --- a/target-sparc/cpu-qom.h
> +++ b/target-sparc/cpu-qom.h
> @@ -71,7 +71,7 @@ static inline SPARCCPU *sparc_env_get_cpu(CPUSPARCState
> *env)
> return container_of(env, SPARCCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(sparc_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)sparc_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(SPARCCPU, env)
>
> diff --git a/target-unicore32/cpu-qom.h b/target-unicore32/cpu-qom.h
> index f727760..a572470 100644
> --- a/target-unicore32/cpu-qom.h
> +++ b/target-unicore32/cpu-qom.h
> @@ -56,7 +56,7 @@ static inline UniCore32CPU
> *uc32_env_get_cpu(CPUUniCore32State *env)
> return container_of(env, UniCore32CPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(uc32_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)uc32_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(UniCore32CPU, env)
>
> diff --git a/target-xtensa/cpu-qom.h b/target-xtensa/cpu-qom.h
> index c6cc2d9..b27425e 100644
> --- a/target-xtensa/cpu-qom.h
> +++ b/target-xtensa/cpu-qom.h
> @@ -79,7 +79,7 @@ static inline XtensaCPU *xtensa_env_get_cpu(const
> CPUXtensaState *env)
> return container_of(env, XtensaCPU, env);
> }
>
> -#define ENV_GET_CPU(e) CPU(xtensa_env_get_cpu(e))
> +#define ENV_GET_CPU(e) ((CPUState *)xtensa_env_get_cpu(e))
>
> #define ENV_OFFSET offsetof(XtensaCPU, env)
>
> --
> 1.8.5.3
>