Re: [Qemu-devel] [Qemu-arm] [PATCH 8/8] target/arm: Implement new do_transaction_failed hook

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Fri, Aug 04, 2017 at 06:20:49PM +0100, Peter Maydell wrote:
> Implement the new do_transaction_failed hook for ARM, which should
> cause the CPU to take a prefetch abort or data abort.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> ---
>  target/arm/internals.h | 10 ++++++++++
>  target/arm/cpu.c       |  1 +
>  target/arm/op_helper.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 54 insertions(+)
> 
> diff --git a/target/arm/internals.h b/target/arm/internals.h
> index a3adbd8..13bb001 100644
> --- a/target/arm/internals.h
> +++ b/target/arm/internals.h
> @@ -471,6 +471,16 @@ void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
>                                   MMUAccessType access_type,
>                                   int mmu_idx, uintptr_t retaddr);
>  
> +/* arm_cpu_do_transaction_failed: handle a memory system error response
> + * (eg "no device/memory present at address") by raising an external abort
> + * exception
> + */
> +void arm_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
> +                                   vaddr addr, unsigned size,
> +                                   MMUAccessType access_type,
> +                                   int mmu_idx, MemTxAttrs attrs,
> +                                   MemTxResult response, uintptr_t retaddr);
> +
>  /* Call the EL change hook if one has been registered */
>  static inline void arm_call_el_change_hook(ARMCPU *cpu)
>  {
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 05c038b..6baede0 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -1670,6 +1670,7 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
>  #else
>      cc->do_interrupt = arm_cpu_do_interrupt;
>      cc->do_unaligned_access = arm_cpu_do_unaligned_access;
> +    cc->do_transaction_failed = arm_cpu_do_transaction_failed;
>      cc->get_phys_page_attrs_debug = arm_cpu_get_phys_page_attrs_debug;
>      cc->asidx_from_attrs = arm_asidx_from_attrs;
>      cc->vmsd = &vmstate_arm_cpu;
> diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c
> index 7eac272..54b6dd8 100644
> --- a/target/arm/op_helper.c
> +++ b/target/arm/op_helper.c
> @@ -229,6 +229,49 @@ void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
>      deliver_fault(cpu, vaddr, access_type, fsr, fsc, &fi);
>  }
>  
> +/* arm_cpu_do_transaction_failed: handle a memory system error response
> + * (eg "no device/memory present at address") by raising an external abort
> + * exception
> + */
> +void arm_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
> +                                   vaddr addr, unsigned size,
> +                                   MMUAccessType access_type,
> +                                   int mmu_idx, MemTxAttrs attrs,
> +                                   MemTxResult response, uintptr_t retaddr)
> +{
> +    ARMCPU *cpu = ARM_CPU(cs);
> +    CPUARMState *env = &cpu->env;
> +    uint32_t fsr, fsc;
> +    ARMMMUFaultInfo fi = {};
> +    ARMMMUIdx arm_mmu_idx = core_to_arm_mmu_idx(env, mmu_idx);
> +
> +    if (retaddr) {
> +        /* now we have a real cpu fault */
> +        cpu_restore_state(cs, retaddr);
> +    }
> +
> +    /* The EA bit in syndromes and fault status registers is an
> +     * IMPDEF classification of external aborts. ARM implementations
> +     * usually use this to indicate AXI bus Decode error (0) or
> +     * Slave error (1); in QEMU we follow that.
> +     */
> +    fi.ea = (response != MEMTX_DECODE_ERROR);
> +
> +    /* The fault status register format depends on whether we're using
> +     * the LPAE long descriptor format, or the short descriptor format.
> +     */
> +    if (arm_s1_regime_using_lpae_format(env, arm_mmu_idx)) {
> +        /* long descriptor form, STATUS 0b010000: synchronous ext abort */
> +        fsr = (fi.ea << 12) | (1 << 9) | 0x10;
> +    } else {
> +        /* short descriptor form, FSR 0b01000 : synchronous ext abort */
> +        fsr = (fi.ea << 12) | 0x8;
> +    }
> +    fsc = 0x10;
> +
> +    deliver_fault(cpu, addr, access_type, fsr, fsc, &fi);
> +}
> +
>  #endif /* !defined(CONFIG_USER_ONLY) */
>  
>  uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b)
> -- 
> 2.7.4
> 
>