Re: [PATCH v2 2/2] target/riscv: do not set mtval2 for non guest-page faults

[Alistair Francis]

On Fri, May 3, 2024 at 8:32 PM Alexei Filippov
<alexei.filippov@syntacore.com> wrote:
>
> Previous patch fixed the PMP priority in raise_mmu_exception() but we're still
> setting mtval2 incorrectly. In riscv_cpu_tlb_fill(), after pmp check in 2 
> stage
> translation part, mtval2 will be set in case of successes 2 stage translation 
> but
> failed pmp check.
>
> In this case we gonna set mtval2 via env->guest_phys_fault_addr in context of
> riscv_cpu_tlb_fill(), as this was a guest-page-fault, but it didn't and mtval2
> should be zero, according to RISCV privileged spec sect. 9.4.4: When a guest
> page-fault is taken into M-mode, mtval2 is written with either zero or guest
> physical address that faulted, shifted by 2 bits. *For other traps, mtval2
> is set to zero...*
>
> Signed-off-by: Alexei Filippov <alexei.filippov@syntacore.com>
> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

Thanks!

Applied to riscv-to-apply.next

Alistair

> ---
> Changes since v1:
>                 -Added Reviewed-by tag.
>  target/riscv/cpu_helper.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index e3a7797d00..484edad900 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -1375,17 +1375,17 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, 
> int size,
>                                __func__, pa, ret, prot_pmp, tlb_size);
>
>                  prot &= prot_pmp;
> -            }
> -
> -            if (ret != TRANSLATE_SUCCESS) {
> +            } else {
>                  /*
>                   * Guest physical address translation failed, this is a HS
>                   * level exception
>                   */
>                  first_stage_error = false;
> -                env->guest_phys_fault_addr = (im_address |
> -                                              (address &
> -                                               (TARGET_PAGE_SIZE - 1))) >> 2;
> +                if (ret != TRANSLATE_PMP_FAIL) {
> +                    env->guest_phys_fault_addr = (im_address |
> +                                                  (address &
> +                                                   (TARGET_PAGE_SIZE - 1))) 
> >> 2;
> +                }
>              }
>          }
>      } else {
> --
> 2.34.1
>
>