target/riscv/csr.c: Turn off mstatus.vs when misa.v is turned off

Commit Message

Evgenii Prokopiev Jan. 14, 2025, 9:20 a.m. UTC

A behavior of misa.v must be similar as misa.f.
So when this bit's field is turned off, mstatus.vs must be turned off
too. It follows from the privileged manual of RISC-V, paragraph 3.1.1.
"Machine ISA (misa) Register".

Signed-off-by: Evgenii Prokopiev <[e-mail]>
---
 target/riscv/csr.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Daniel Henrique Barboza Jan. 14, 2025, 1:02 p.m. UTC | #1

On 1/14/25 6:20 AM, Evgenii Prokopiev wrote:
> A behavior of misa.v must be similar as misa.f.
> So when this bit's field is turned off, mstatus.vs must be turned off
> too. It follows from the privileged manual of RISC-V, paragraph 3.1.1.
> "Machine ISA (misa) Register".
> 
> Signed-off-by: Evgenii Prokopiev <[e-mail]>
> ---

Reviewed-by: Daniel Henrique Barboza <[e-mail]>

>   target/riscv/csr.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index eab8e50012..fca2b1b40f 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -1537,6 +1537,10 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>           env->mstatus &= ~MSTATUS_FS;
>       }
>   
> +    if (!(env->misa_ext & RVV)) {
> +        env->mstatus &= ~MSTATUS_VS;
> +    }
> +
>       /* flush translation cache */
>       tb_flush(env_cpu(env));
>       env->xl = riscv_cpu_mxl(env);

Patch

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index eab8e50012..fca2b1b40f 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1537,6 +1537,10 @@  static RISCVException write_misa(CPURISCVState *env, int csrno,
         env->mstatus &= ~MSTATUS_FS;
     }
 
+    if (!(env->misa_ext & RVV)) {
+        env->mstatus &= ~MSTATUS_VS;
+    }
+
     /* flush translation cache */
     tb_flush(env_cpu(env));
     env->xl = riscv_cpu_mxl(env);