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).

Signed-off-by: Max Chou <max.chou@sifive.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;
     }
 
-- 
2.34.1

24.01.2025 12:05, 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).

Is this a qemu-stable material?

If yes, how important it is to pick it up for 8.2 and 7.2 series,
where the patch does not apply directly?

I currently picked it for 9.2 series only.

Please keep qemu-stable@ in Cc for future changes which should be
picked up for stable series.

Thanks,

/mjt

06.03.2025 09:28, Michael Tokarev wrote:

> ... how important it is to pick it up for 8.2 and 7.2 series,
> where the patch does not apply directly?

Scratch this.  It is applicable for 9.2 only (from the currently
active stable series), b/c it fixes a commit after 8.2

Thanks,

/mjt

On Fri, Jan 24, 2025 at 7:06 PM Max Chou <max.chou@sifive.com> 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).
>
> Signed-off-by: Max Chou <max.chou@sifive.com>

Thanks!

Applied to riscv-to-apply.next

Alistair

> ---
>  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;
>      }
>
> --
> 2.34.1
>
>

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;
>       }
>