Re: [PATCH v6 13/25] target/mips: call plugin trap callbacks

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi Julian,

On 4/9/25 22:46, Julian Ganz wrote:
> We recently introduced API for registering callbacks for trap related
> events as well as the corresponding hook functions. Due to differences
> between architectures, the latter need to be called from target specific
> code.
> 
> This change places hooks for MIPS targets. We consider the exceptions
> NMI and EXT_INTERRUPT to be asynchronous interrupts rather than
> exceptions.
> 
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Julian Ganz <neither@nut.email>
> ---
>   target/mips/tcg/system/tlb_helper.c | 11 +++++++++++
>   1 file changed, 11 insertions(+)
> 
> diff --git a/target/mips/tcg/system/tlb_helper.c b/target/mips/tcg/system/tlb_helper.c
> index 1e8901556d..566924b079 100644
> --- a/target/mips/tcg/system/tlb_helper.c
> +++ b/target/mips/tcg/system/tlb_helper.c
> @@ -18,6 +18,7 @@
>    */
>   #include "qemu/osdep.h"
>   #include "qemu/bitops.h"
> +#include "qemu/plugin.h"
>   
>   #include "cpu.h"
>   #include "internal.h"
> @@ -1034,6 +1035,7 @@ void mips_cpu_do_interrupt(CPUState *cs)
>       bool update_badinstr = 0;
>       target_ulong offset;
>       int cause = -1;
> +    uint64_t last_pc = env->active_tc.PC;
>   
>       if (qemu_loglevel_mask(CPU_LOG_INT)
>           && cs->exception_index != EXCP_EXT_INTERRUPT) {
> @@ -1052,6 +1054,7 @@ void mips_cpu_do_interrupt(CPUState *cs)
>           cs->exception_index = EXCP_NONE;

I wonder why this code path is different. I'd unify by removing this
line and replacing s/return/break/, then handle in the switch case
you add at the end.

Anyway,

Acked-by: Philippe Mathieu-Daudé <philmd@linaro.org>

>           mips_semihosting(env);
>           env->active_tc.PC += env->error_code;
> +        qemu_plugin_vcpu_hostcall_cb(cs, last_pc);
>           return;
>       case EXCP_DSS:
>           env->CP0_Debug |= 1 << CP0DB_DSS;
> @@ -1336,6 +1339,14 @@ void mips_cpu_do_interrupt(CPUState *cs)
>                    env->CP0_Status, env->CP0_Cause, env->CP0_BadVAddr,
>                    env->CP0_DEPC);
>       }
> +    switch (cs->exception_index) {
> +    case EXCP_NMI:
> +    case EXCP_EXT_INTERRUPT:
> +        qemu_plugin_vcpu_interrupt_cb(cs, last_pc);
> +        break;
> +    default:
> +        qemu_plugin_vcpu_exception_cb(cs, last_pc);
> +    }
>       cs->exception_index = EXCP_NONE;
>   }
>