On Tue, Nov 21, 2023 at 6:51 PM Ivan Klokov <ivan.klo...@syntacore.com> wrote:
>
> According to RISCV privileged spec sect. 5.3.2 Virtual Address Translation
> Process
> access-fault exceptions may raise only after PMA/PMP check. Current
> implementation
> generates an access-fault for mbare mode even if there were no PMA/PMP errors.
> This patch removes the erroneous MMU mode check and generates an access-fault
> exception based on the pmp_violation flag only.
>
> Fixes: 1448689c7b ("target/riscv: Allow specifying MMU stage")
>
> Signed-off-by: Ivan Klokov <ivan.klo...@syntacore.com>
Please keep existing tags when sending a new version if there aren't any changes
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> ---
> target/riscv/cpu_helper.c | 30 +++++++-----------------------
> 1 file changed, 7 insertions(+), 23 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index b7af69de53..9ff0952e46 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -1143,47 +1143,31 @@ static void raise_mmu_exception(CPURISCVState *env,
> target_ulong address,
> bool two_stage_indirect)
> {
> CPUState *cs = env_cpu(env);
> - int page_fault_exceptions, vm;
> - uint64_t stap_mode;
> -
> - if (riscv_cpu_mxl(env) == MXL_RV32) {
> - stap_mode = SATP32_MODE;
> - } else {
> - stap_mode = SATP64_MODE;
> - }
> -
> - if (first_stage) {
> - vm = get_field(env->satp, stap_mode);
> - } else {
> - vm = get_field(env->hgatp, stap_mode);
> - }
> -
> - page_fault_exceptions = vm != VM_1_10_MBARE && !pmp_violation;
>
> switch (access_type) {
> case MMU_INST_FETCH:
> if (env->virt_enabled && !first_stage) {
> cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
> } else {
> - cs->exception_index = page_fault_exceptions ?
> - RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
> + cs->exception_index = pmp_violation ?
> + RISCV_EXCP_INST_ACCESS_FAULT : RISCV_EXCP_INST_PAGE_FAULT;
> }
> break;
> case MMU_DATA_LOAD:
> if (two_stage && !first_stage) {
> cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
> } else {
> - cs->exception_index = page_fault_exceptions ?
> - RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
> + cs->exception_index = pmp_violation ?
> + RISCV_EXCP_LOAD_ACCESS_FAULT : RISCV_EXCP_LOAD_PAGE_FAULT;
> }
> break;
> case MMU_DATA_STORE:
> if (two_stage && !first_stage) {
> cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
> } else {
> - cs->exception_index = page_fault_exceptions ?
> - RISCV_EXCP_STORE_PAGE_FAULT :
> - RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
> + cs->exception_index = pmp_violation ?
> + RISCV_EXCP_STORE_AMO_ACCESS_FAULT :
> + RISCV_EXCP_STORE_PAGE_FAULT;
> }
> break;
> default:
> --
> 2.34.1
>
>
