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.c...@sifive.com>
---

Reviewed-by: Daniel Henrique Barboza <dbarb...@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;
      }