Re: [Qemu-devel] [PATCH 4/5 v3] RISC-V: Add debug support for accessing CSRs.

[Alistair Francis]

On Tue, Jan 29, 2019 at 6:57 PM Jim Wilson <address@hidden> wrote:
>
> Adds a debugger field to CPURISCVState.  Disable mode checks in riscv_csrrw
> when true.
>
> Signed-off-by: Jim Wilson <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Alistair

> ---
>  target/riscv/cpu.h |  3 +++
>  target/riscv/csr.c | 16 ++++++++--------
>  2 files changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 743f02c..faa46d0 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -170,6 +170,9 @@ struct CPURISCVState {
>
>      /* physical memory protection */
>      pmp_table_t pmp_state;
> +
> +    /* True if in debugger mode.  */
> +    bool debugger;
>  #endif
>
>      float_status fp_status;
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 5e7e7d1..04e6b59 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -46,7 +46,7 @@ void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops)
>  static int fs(CPURISCVState *env, int csrno)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>  #endif
> @@ -58,7 +58,7 @@ static int ctr(CPURISCVState *env, int csrno)
>  #if !defined(CONFIG_USER_ONLY)
>      target_ulong ctr_en = env->priv == PRV_U ? env->scounteren :
>                            env->priv == PRV_S ? env->mcounteren : -1U;
> -    if (!(ctr_en & (1 << (csrno & 31)))) {
> +    if (!env->debugger && !(ctr_en & (1 << (csrno & 31)))) {
>          return -1;
>      }
>  #endif
> @@ -86,7 +86,7 @@ static int pmp(CPURISCVState *env, int csrno)
>  static int read_fflags(CPURISCVState *env, int csrno, target_ulong *val)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>  #endif
> @@ -97,7 +97,7 @@ static int read_fflags(CPURISCVState *env, int csrno, 
> target_ulong *val)
>  static int write_fflags(CPURISCVState *env, int csrno, target_ulong val)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>      env->mstatus |= MSTATUS_FS;
> @@ -109,7 +109,7 @@ static int write_fflags(CPURISCVState *env, int csrno, 
> target_ulong val)
>  static int read_frm(CPURISCVState *env, int csrno, target_ulong *val)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>  #endif
> @@ -120,7 +120,7 @@ static int read_frm(CPURISCVState *env, int csrno, 
> target_ulong *val)
>  static int write_frm(CPURISCVState *env, int csrno, target_ulong val)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>      env->mstatus |= MSTATUS_FS;
> @@ -132,7 +132,7 @@ static int write_frm(CPURISCVState *env, int csrno, 
> target_ulong val)
>  static int read_fcsr(CPURISCVState *env, int csrno, target_ulong *val)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>  #endif
> @@ -144,7 +144,7 @@ static int read_fcsr(CPURISCVState *env, int csrno, 
> target_ulong *val)
>  static int write_fcsr(CPURISCVState *env, int csrno, target_ulong val)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> -    if (!(env->mstatus & MSTATUS_FS)) {
> +    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
>          return -1;
>      }
>      env->mstatus |= MSTATUS_FS;
> --
> 2.7.4
>
>