Re: [PATCH 1/2] target/mips: Fold jazz behaviour into mips_cpu_do_transaction_failed

[Philippe Mathieu-Daudé]

On 2/28/21 12:25 AM, Richard Henderson wrote:
> Add a flag to MIPSCPUClass in order to avoid needing to
> replace mips_tcg_ops.do_transaction_failed.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/mips/cpu-qom.h   |  3 +++
>  hw/mips/jazz.c          | 35 +++--------------------------------
>  target/mips/op_helper.c |  3 ++-
>  3 files changed, 8 insertions(+), 33 deletions(-)
...
> diff --git a/hw/mips/jazz.c b/hw/mips/jazz.c
> index 83c8086062..7b22a9b511 100644
> --- a/hw/mips/jazz.c
> +++ b/hw/mips/jazz.c
...> @@ -152,7 +128,7 @@ static void mips_jazz_init(MachineState *machine,
>      int bios_size, n;
>      Clock *cpuclk;
>      MIPSCPU *cpu;
> -    CPUClass *cc;
> +    MIPSCPUClass *mcc;
>      CPUMIPSState *env;
>      qemu_irq *i8259;
>      rc4030_dma *dmas;
> @@ -199,8 +175,6 @@ static void mips_jazz_init(MachineState *machine,
>       * However, we can't simply add a global memory region to catch
>       * everything, as this would make all accesses including instruction
>       * accesses be ignored and not raise exceptions.
> -     * So instead we hijack the do_transaction_failed method on the CPU, and
> -     * do not raise exceptions for data access.
>       *
>       * NOTE: this behaviour of raising exceptions for bad instruction
>       * fetches but not bad data accesses was added in commit 54e755588cf1e9
> @@ -210,11 +184,8 @@ static void mips_jazz_init(MachineState *machine,
>       * we could replace this hijacking of CPU methods with a simple global
>       * memory region that catches all memory accesses, as we do on Malta.
>       */
> -    cc = CPU_GET_CLASS(cpu);
> -#if defined(CONFIG_TCG) && !defined(CONFIG_USER_ONLY)
> -    real_do_transaction_failed = cc->tcg_ops->do_transaction_failed;
> -    cc->tcg_ops->do_transaction_failed = mips_jazz_do_transaction_failed;

We don't need the "hw/core/tcg-cpu-ops.h" header anymore.

> -#endif /* CONFIG_TCG && !CONFIG_USER_ONLY */
> +    mcc = MIPS_CPU_GET_CLASS(cpu);
> +    mcc->no_data_aborts = true;