Re: [Qemu-devel] [Qemu-arm] [PATCH v2 01/67] target/arm: Enable SVE for aarch64-linux-user

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> Enable ARM_FEATURE_SVE for the generic "any" cpu.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/cpu.c   | 7 +++++++
>  target/arm/cpu64.c | 1 +
>  2 files changed, 8 insertions(+)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 1b3ae62db6..10843994c3 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -150,6 +150,13 @@ static void arm_cpu_reset(CPUState *s)
>          env->cp15.sctlr_el[1] |= SCTLR_UCT | SCTLR_UCI | SCTLR_DZE;
>          /* and to the FP/Neon instructions */
>          env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 20, 2, 3);
> +        /* and to the SVE instructions */
> +        env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 16, 2, 3);
> +        env->cp15.cptr_el[3] |= CPTR_EZ;
> +        /* with maximum vector length */
> +        env->vfp.zcr_el[1] = ARM_MAX_VQ - 1;
> +        env->vfp.zcr_el[2] = ARM_MAX_VQ - 1;
> +        env->vfp.zcr_el[3] = ARM_MAX_VQ - 1;
>  #else

I notice this is linux-user only but what happens if you specify a
specific CPU in linux-user mode, do we still end up running SVE specific
initialisation?

It seems to me that we should be seeing feature guarded reset stuff in here.

>          /* Reset into the highest available EL */
>          if (arm_feature(env, ARM_FEATURE_EL3)) {
> diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
> index efc519b49b..36ef9e9d9d 100644
> --- a/target/arm/cpu64.c
> +++ b/target/arm/cpu64.c
> @@ -231,6 +231,7 @@ static void aarch64_any_initfn(Object *obj)
>      set_feature(&cpu->env, ARM_FEATURE_V8_PMULL);
>      set_feature(&cpu->env, ARM_FEATURE_CRC);
>      set_feature(&cpu->env, ARM_FEATURE_V8_FP16);
> +    set_feature(&cpu->env, ARM_FEATURE_SVE);
>      cpu->ctr = 0x80038003; /* 32 byte I and D cacheline size, VIPT icache */
>      cpu->dcz_blocksize = 7; /*  512 bytes */
>  }


--
Alex Bennée