Re: [RFC PATCH v5 12/22] target/arm: Handle NMI in arm_cpu_do_interrupt_aarch64()

[Richard Henderson]

On 2/29/24 03:10, Jinjie Ruan via wrote:
> According to Arm GIC section 4.6.3 Interrupt superpriority, the interrupt
> with superpriority is always IRQ, never FIQ, so the NMI exception trap entry
> behave like IRQ. However, VNMI can be IRQ or FIQ, FIQ can only come from
> hcrx_el2.HCRX_VFNMI bit, IRQ can be raised from the GIC or come from the
> hcrx_el2.HCRX_VINMI bit.
>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> v4:
> - Also handle VNMI in arm_cpu_do_interrupt_aarch64().
> v3:
> - Remove the FIQ NMI handle.
> ---
>   target/arm/helper.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index b796dbdf21..bd34b3506a 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -11459,12 +11459,21 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs)
>           break;
>       case EXCP_IRQ:
>       case EXCP_VIRQ:
> +    case EXCP_NMI:
>           addr += 0x80;
>           break;
>       case EXCP_FIQ:
>       case EXCP_VFIQ:
>           addr += 0x100;
>           break;
> +    case EXCP_VNMI:
> +        if (env->irq_line_state & CPU_INTERRUPT_VNMI ||
> +            env->cp15.hcrx_el2 & HCRX_VINMI) {
> +            addr += 0x80;
> +        } else if (env->cp15.hcrx_el2 & HCRX_VFNMI) {
> +            addr += 0x100;
> +        }
> +        break;

By not combining VFNMI with CPU_INTERRUPT_VNMI, you don't need this 
complication.
Just

     case EXCP_IRQ:
     case EXCP_VIRQ:
+    case EXCP_NMI:


r~