[v2] target/riscv: Various fixes to gdbstub and CSR access

[PATCH v2 17/18] target/riscv: Drop priv level check in mseccfg predicate()

Posted by Bin Meng 2 years, 11 months ago

From: Bin Meng <bmeng@tinylab.org>

riscv_csrrw_check() already does the generic privilege level check
hence there is no need to do the specific M-mode access check in
the mseccfg predicate().

With this change debugger can access the mseccfg CSR anytime.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
---

(no changes since v1)

 target/riscv/csr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 020c3f524f..785f6f4d45 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -451,7 +451,7 @@ static RISCVException pmp(CPURISCVState *env, int csrno)
 
 static RISCVException epmp(CPURISCVState *env, int csrno)
 {
-    if (env->priv == PRV_M && riscv_cpu_cfg(env)->epmp) {
+    if (riscv_cpu_cfg(env)->epmp) {
         return RISCV_EXCP_NONE;
     }
 
-- 
2.25.1

Re: [PATCH v2 17/18] target/riscv: Drop priv level check in mseccfg predicate()

Posted by LIU Zhiwei 2 years, 11 months ago

On 2023/2/28 21:45, Bin Meng wrote:
> From: Bin Meng <bmeng@tinylab.org>
>
> riscv_csrrw_check() already does the generic privilege level check
> hence there is no need to do the specific M-mode access check in
> the mseccfg predicate().
>
> With this change debugger can access the mseccfg CSR anytime.
>
> Signed-off-by: Bin Meng <bmeng@tinylab.org>
> Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
> ---
>
> (no changes since v1)
>
>   target/riscv/csr.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 020c3f524f..785f6f4d45 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -451,7 +451,7 @@ static RISCVException pmp(CPURISCVState *env, int csrno)
>   
>   static RISCVException epmp(CPURISCVState *env, int csrno)
>   {
> -    if (env->priv == PRV_M && riscv_cpu_cfg(env)->epmp) {
> +    if (riscv_cpu_cfg(env)->epmp) {

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

>           return RISCV_EXCP_NONE;
>       }
>