target/riscv: rvv: Fix incorrect vlen comparison in prop_vlen_set

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>
Message-ID: <20250124090539.2506448-1-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index d7ecf72..99436f1 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2027,6 +2027,7 @@ 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)) {
@@ -2038,10 +2039,10 @@ 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;
     }