Re: [PATCH v2 4/4] linux-user/sparc: Handle tstate in sparc64_get/set_context()

[Laurent Vivier <laurent@vivier.eu>]

Le 06/11/2020 à 16:27, Peter Maydell a écrit :
> Correctly implement save/restore of the tstate field in
> sparc64_get_context() and sparc64_set_context():
>  * Don't use the CWP value from the guest in set_context
>  * Construct and save a tstate value rather than leaving
>    it as zero in get_context
> 
> To do this we factor out the "calculate TSTATE value from CPU state"
> code from sparc_cpu_do_interrupt() into its own sparc64_tstate()
> function; that in turn requires us to move some of the function
> prototypes out from inside a CPU_NO_IO_DEFS ifdef guard.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target/sparc/cpu.h          | 24 ++++++++++++++++++++----
>  linux-user/sparc/signal.c   |  7 +++----
>  target/sparc/int64_helper.c |  5 +----
>  3 files changed, 24 insertions(+), 12 deletions(-)
> 
> diff --git a/target/sparc/cpu.h b/target/sparc/cpu.h
> index 277254732b9..4b2290650be 100644
> --- a/target/sparc/cpu.h
> +++ b/target/sparc/cpu.h
> @@ -608,10 +608,6 @@ target_ulong cpu_get_psr(CPUSPARCState *env1);
>  void cpu_put_psr(CPUSPARCState *env1, target_ulong val);
>  void cpu_put_psr_raw(CPUSPARCState *env1, target_ulong val);
>  #ifdef TARGET_SPARC64
> -target_ulong cpu_get_ccr(CPUSPARCState *env1);
> -void cpu_put_ccr(CPUSPARCState *env1, target_ulong val);
> -target_ulong cpu_get_cwp64(CPUSPARCState *env1);
> -void cpu_put_cwp64(CPUSPARCState *env1, int cwp);
>  void cpu_change_pstate(CPUSPARCState *env1, uint32_t new_pstate);
>  void cpu_gl_switch_gregs(CPUSPARCState *env, uint32_t new_gl);
>  #endif
> @@ -829,4 +825,24 @@ static inline bool tb_am_enabled(int tb_flags)
>  #endif
>  }
>  
> +#ifdef TARGET_SPARC64
> +/* win_helper.c */
> +target_ulong cpu_get_ccr(CPUSPARCState *env1);
> +void cpu_put_ccr(CPUSPARCState *env1, target_ulong val);
> +target_ulong cpu_get_cwp64(CPUSPARCState *env1);
> +void cpu_put_cwp64(CPUSPARCState *env1, int cwp);
> +
> +static inline uint64_t sparc64_tstate(CPUSPARCState *env)
> +{
> +    uint64_t tstate = (cpu_get_ccr(env) << 32) |
> +        ((env->asi & 0xff) << 24) | ((env->pstate & 0xf3f) << 8) |
> +        cpu_get_cwp64(env);
> +
> +    if (env->def.features & CPU_FEATURE_GL) {
> +        tstate |= (env->gl & 7ULL) << 40;
> +    }
> +    return tstate;
> +}
> +#endif
> +
>  #endif
> diff --git a/linux-user/sparc/signal.c b/linux-user/sparc/signal.c
> index ed32c7abd17..a6c7c7664a2 100644
> --- a/linux-user/sparc/signal.c
> +++ b/linux-user/sparc/signal.c
> @@ -438,9 +438,9 @@ void sparc64_set_context(CPUSPARCState *env)
>      env->npc = npc;
>      __get_user(env->y, &((*grp)[SPARC_MC_Y]));
>      __get_user(tstate, &((*grp)[SPARC_MC_TSTATE]));
> +    /* Honour TSTATE_ASI, TSTATE_ICC and TSTATE_XCC only */
>      env->asi = (tstate >> 24) & 0xff;
> -    cpu_put_ccr(env, tstate >> 32);
> -    cpu_put_cwp64(env, tstate & 0x1f);
> +    cpu_put_ccr(env, (tstate >> 32) & 0xff);
>      __get_user(env->gregs[1], (&(*grp)[SPARC_MC_G1]));
>      __get_user(env->gregs[2], (&(*grp)[SPARC_MC_G2]));
>      __get_user(env->gregs[3], (&(*grp)[SPARC_MC_G3]));
> @@ -557,8 +557,7 @@ void sparc64_get_context(CPUSPARCState *env)
>          }
>      }
>  
> -    /* XXX: tstate must be saved properly */
> -    //    __put_user(env->tstate, &((*grp)[SPARC_MC_TSTATE]));
> +    __put_user(sparc64_tstate(env), &((*grp)[SPARC_MC_TSTATE]));
>      __put_user(env->pc, &((*grp)[SPARC_MC_PC]));
>      __put_user(env->npc, &((*grp)[SPARC_MC_NPC]));
>      __put_user(env->y, &((*grp)[SPARC_MC_Y]));
> diff --git a/target/sparc/int64_helper.c b/target/sparc/int64_helper.c
> index f3e7f32de61..735668f5006 100644
> --- a/target/sparc/int64_helper.c
> +++ b/target/sparc/int64_helper.c
> @@ -131,9 +131,7 @@ void sparc_cpu_do_interrupt(CPUState *cs)
>      }
>      tsptr = cpu_tsptr(env);
>  
> -    tsptr->tstate = (cpu_get_ccr(env) << 32) |
> -        ((env->asi & 0xff) << 24) | ((env->pstate & 0xf3f) << 8) |
> -        cpu_get_cwp64(env);
> +    tsptr->tstate = sparc64_tstate(env);
>      tsptr->tpc = env->pc;
>      tsptr->tnpc = env->npc;
>      tsptr->tt = intno;
> @@ -148,7 +146,6 @@ void sparc_cpu_do_interrupt(CPUState *cs)
>      }
>  
>      if (env->def.features & CPU_FEATURE_GL) {
> -        tsptr->tstate |= (env->gl & 7ULL) << 40;
>          cpu_gl_switch_gregs(env, env->gl + 1);
>          env->gl++;
>      }
> 

Applied to my linux-user-for-6.0 branch.

Thanks,
Laurent