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From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>,
	qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH 2/2] target/arm: Remove no-longer-reachable 32-bit KVM code
Date: Fri, 4 Sep 2020 18:01:34 +0200	[thread overview]
Message-ID: <11457fd8-725f-5836-e2ef-6c60aee344e5@redhat.com> (raw)
In-Reply-To: <20200904154156.31943-3-peter.maydell@linaro.org>

On 9/4/20 5:41 PM, Peter Maydell wrote:
> Now that 32-bit KVM host support is gone, KVM can never
> be enabled unless CONFIG_AARCH64 is true, and some code
> paths are no longer reachable and can be deleted.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
[...]
>  static void arm_max_initfn(Object *obj)
>  {
>      ARMCPU *cpu = ARM_CPU(obj);
>  
> -    if (kvm_enabled()) {
> -        kvm_arm_set_cpu_features_from_host(cpu);
> -    } else {
> -        cortex_a15_initfn(obj);
> +    cortex_a15_initfn(obj);
>  
> -        /* old-style VFP short-vector support */
> -        cpu->isar.mvfr0 = FIELD_DP32(cpu->isar.mvfr0, MVFR0, FPSHVEC, 1);
> +    /* old-style VFP short-vector support */
> +    cpu->isar.mvfr0 = FIELD_DP32(cpu->isar.mvfr0, MVFR0, FPSHVEC, 1);
>  
>  #ifdef CONFIG_USER_ONLY
> -        /* We don't set these in system emulation mode for the moment,
> -         * since we don't correctly set (all of) the ID registers to
> -         * advertise them.
> -         */
> -        set_feature(&cpu->env, ARM_FEATURE_V8);
> -        {
> -            uint32_t t;
> +    /* We don't set these in system emulation mode for the moment,

checkpatch might warn "block comment ... separate line" :/

> +     * since we don't correctly set (all of) the ID registers to
> +     * advertise them.
> +     */
> +    set_feature(&cpu->env, ARM_FEATURE_V8);
> +    {
> +        uint32_t t;
>  
> -            t = cpu->isar.id_isar5;
> -            t = FIELD_DP32(t, ID_ISAR5, AES, 2);
> -            t = FIELD_DP32(t, ID_ISAR5, SHA1, 1);
> -            t = FIELD_DP32(t, ID_ISAR5, SHA2, 1);
> -            t = FIELD_DP32(t, ID_ISAR5, CRC32, 1);
> -            t = FIELD_DP32(t, ID_ISAR5, RDM, 1);
> -            t = FIELD_DP32(t, ID_ISAR5, VCMA, 1);
> -            cpu->isar.id_isar5 = t;
> +        t = cpu->isar.id_isar5;
> +        t = FIELD_DP32(t, ID_ISAR5, AES, 2);
> +        t = FIELD_DP32(t, ID_ISAR5, SHA1, 1);
> +        t = FIELD_DP32(t, ID_ISAR5, SHA2, 1);
> +        t = FIELD_DP32(t, ID_ISAR5, CRC32, 1);
> +        t = FIELD_DP32(t, ID_ISAR5, RDM, 1);
> +        t = FIELD_DP32(t, ID_ISAR5, VCMA, 1);
> +        cpu->isar.id_isar5 = t;
>  
> -            t = cpu->isar.id_isar6;
> -            t = FIELD_DP32(t, ID_ISAR6, JSCVT, 1);
> -            t = FIELD_DP32(t, ID_ISAR6, DP, 1);
> -            t = FIELD_DP32(t, ID_ISAR6, FHM, 1);
> -            t = FIELD_DP32(t, ID_ISAR6, SB, 1);
> -            t = FIELD_DP32(t, ID_ISAR6, SPECRES, 1);
> -            cpu->isar.id_isar6 = t;
> +        t = cpu->isar.id_isar6;
> +        t = FIELD_DP32(t, ID_ISAR6, JSCVT, 1);
> +        t = FIELD_DP32(t, ID_ISAR6, DP, 1);
> +        t = FIELD_DP32(t, ID_ISAR6, FHM, 1);
> +        t = FIELD_DP32(t, ID_ISAR6, SB, 1);
> +        t = FIELD_DP32(t, ID_ISAR6, SPECRES, 1);
> +        cpu->isar.id_isar6 = t;
>  
> -            t = cpu->isar.mvfr1;
> -            t = FIELD_DP32(t, MVFR1, FPHP, 3);     /* v8.2-FP16 */
> -            t = FIELD_DP32(t, MVFR1, SIMDHP, 2);   /* v8.2-FP16 */
> -            cpu->isar.mvfr1 = t;
> +        t = cpu->isar.mvfr1;
> +        t = FIELD_DP32(t, MVFR1, FPHP, 3);     /* v8.2-FP16 */
> +        t = FIELD_DP32(t, MVFR1, SIMDHP, 2);   /* v8.2-FP16 */
> +        cpu->isar.mvfr1 = t;
>  
> -            t = cpu->isar.mvfr2;
> -            t = FIELD_DP32(t, MVFR2, SIMDMISC, 3); /* SIMD MaxNum */
> -            t = FIELD_DP32(t, MVFR2, FPMISC, 4);   /* FP MaxNum */
> -            cpu->isar.mvfr2 = t;
> +        t = cpu->isar.mvfr2;
> +        t = FIELD_DP32(t, MVFR2, SIMDMISC, 3); /* SIMD MaxNum */
> +        t = FIELD_DP32(t, MVFR2, FPMISC, 4);   /* FP MaxNum */
> +        cpu->isar.mvfr2 = t;
>  
> -            t = cpu->isar.id_mmfr3;
> -            t = FIELD_DP32(t, ID_MMFR3, PAN, 2); /* ATS1E1 */
> -            cpu->isar.id_mmfr3 = t;
> +        t = cpu->isar.id_mmfr3;
> +        t = FIELD_DP32(t, ID_MMFR3, PAN, 2); /* ATS1E1 */
> +        cpu->isar.id_mmfr3 = t;
>  
> -            t = cpu->isar.id_mmfr4;
> -            t = FIELD_DP32(t, ID_MMFR4, HPDS, 1); /* AA32HPD */
> -            t = FIELD_DP32(t, ID_MMFR4, AC2, 1); /* ACTLR2, HACTLR2 */
> -            t = FIELD_DP32(t, ID_MMFR4, CNP, 1); /* TTCNP */
> -            t = FIELD_DP32(t, ID_MMFR4, XNX, 1); /* TTS2UXN */
> -            cpu->isar.id_mmfr4 = t;
> -        }
> -#endif
> +        t = cpu->isar.id_mmfr4;
> +        t = FIELD_DP32(t, ID_MMFR4, HPDS, 1); /* AA32HPD */
> +        t = FIELD_DP32(t, ID_MMFR4, AC2, 1); /* ACTLR2, HACTLR2 */
> +        t = FIELD_DP32(t, ID_MMFR4, CNP, 1); /* TTCNP */
> +        t = FIELD_DP32(t, ID_MMFR4, XNX, 1); /* TTS2UXN */
> +        cpu->isar.id_mmfr4 = t;
>      }
> +#endif

Scary :) This is the if {} else {} removed, OK.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>  }
>  #endif
>  
> @@ -2269,11 +2265,7 @@ static void arm_host_initfn(Object *obj)
>  
>  static const TypeInfo host_arm_cpu_type_info = {
>      .name = TYPE_ARM_HOST_CPU,
> -#ifdef TARGET_AARCH64
>      .parent = TYPE_AARCH64_CPU,
> -#else
> -    .parent = TYPE_ARM_CPU,
> -#endif
>      .instance_init = arm_host_initfn,
>  };
[...]



  reply	other threads:[~2020-09-04 16:05 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-04 15:41 [PATCH 0/2] Remove KVM support for 32-bit Arm hosts Peter Maydell
2020-09-04 15:41 ` [PATCH 1/2] target/arm: " Peter Maydell
2020-09-04 16:01   ` Philippe Mathieu-Daudé
2020-09-04 15:41 ` [PATCH 2/2] target/arm: Remove no-longer-reachable 32-bit KVM code Peter Maydell
2020-09-04 16:01   ` Philippe Mathieu-Daudé [this message]
2020-09-04 16:06     ` Peter Maydell
2020-09-04 15:50 ` [PATCH 0/2] Remove KVM support for 32-bit Arm hosts Richard Henderson
2020-09-04 15:51 ` no-reply

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