Re: [PATCH] target/riscv: rvv: Fix incorrect vlen comparison in prop_vlen_set

[Daniel Henrique Barboza]

On 1/24/25 6:05 AM, Max Chou wrote:
> In prop_vlen_set function, there is an incorrect comparison between
> vlen(bit) and vlenb(byte).
> This will cause unexpected error when user applies the `vlen=1024` cpu
> option with a vendor predefined cpu type that the default vlen is
> 1024(vlenb=128).

Fixes: 4f6d036ccc ("target/riscv/cpu.c: remove cpu->cfg.vlen")

> Signed-off-by: Max Chou <max.chou@sifive.com>
> ---

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

>   target/riscv/cpu.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 3d4bd157d2c..2f53acbab59 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -2034,6 +2034,7 @@ static void prop_vlen_set(Object *obj, Visitor *v, const 
> char *name,
>                            void *opaque, Error **errp)
>   {
>       RISCVCPU *cpu = RISCV_CPU(obj);
> +    uint16_t cpu_vlen = cpu->cfg.vlenb << 3;
>       uint16_t value;
>   
>       if (!visit_type_uint16(v, name, &value, errp)) {
> @@ -2045,10 +2046,10 @@ static void prop_vlen_set(Object *obj, Visitor *v, 
> const char *name,
>           return;
>       }
>   
> -    if (value != cpu->cfg.vlenb && riscv_cpu_is_vendor(obj)) {
> +    if (value != cpu_vlen && riscv_cpu_is_vendor(obj)) {
>           cpu_set_prop_err(cpu, name, errp);
>           error_append_hint(errp, "Current '%s' val: %u\n",
> -                          name, cpu->cfg.vlenb << 3);
> +                          name, cpu_vlen);
>           return;
>       }
>