Re: [PATCH v2 2/2] target/riscv: Move Guest irqs out of the core local irqs range.

[Alistair Francis]

On Mon, May 20, 2024 at 10:52 PM Rajnesh Kanwal <rkanwal@rivosinc.com> wrote:
>
> Qemu maps IRQs 0:15 for core interrupts and 16 onward for
> guest interrupts which are later translated to hgiep in
> `riscv_cpu_set_irq()` function.
>
> With virtual IRQ support added, software now can fully
> use the whole local interrupt range without any actual
> hardware attached.
>
> This change moves the guest interrupt range after the
> core local interrupt range to avoid clash.
>
> Fixes: 1697837ed9 ("target/riscv: Add M-mode virtual interrupt and IRQ 
> filtering support.")
> Fixes: 40336d5b1d ("target/riscv: Add HS-mode virtual interrupt and IRQ 
> filtering support.")
>
> Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>

Acked-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/cpu_bits.h | 3 ++-
>  target/riscv/csr.c      | 9 ++++++++-
>  2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 74318a925c..a470fda9be 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -695,7 +695,8 @@ typedef enum RISCVException {
>  #define IRQ_M_EXT                          11
>  #define IRQ_S_GEXT                         12
>  #define IRQ_PMU_OVF                        13
> -#define IRQ_LOCAL_MAX                      16
> +#define IRQ_LOCAL_MAX                      64
> +/* -1 is due to bit zero of hgeip and hgeie being ROZ. */
>  #define IRQ_LOCAL_GUEST_MAX                (TARGET_LONG_BITS - 1)
>
>  /* mip masks */
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 152796ebc0..464e0e57a3 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -1148,7 +1148,14 @@ static RISCVException write_stimecmph(CPURISCVState 
> *env, int csrno,
>
>  #define VSTOPI_NUM_SRCS 5
>
> -#define LOCAL_INTERRUPTS (~0x1FFF)
> +/*
> + * All core local interrupts except the fixed ones 0:12. This macro is for
> + * virtual interrupts logic so please don't change this to avoid messing up
> + * the whole support, For reference see AIA spec: `5.3 Interrupt filtering 
> and
> + * virtual interrupts for supervisor level` and `6.3.2 Virtual interrupts for
> + * VS level`.
> + */
> +#define LOCAL_INTERRUPTS   (~0x1FFFULL)
>
>  static const uint64_t delegable_ints =
>      S_MODE_INTERRUPTS | VS_MODE_INTERRUPTS | MIP_LCOFIP;
> --
> 2.34.1
>
>