Re: [Qemu-devel] [PATCH 05/24] target-arm: Add exception level to the AArch64 TB flags

[Peter Crosthwaite]

On Wed, Jan 22, 2014 at 6:12 AM, Peter Maydell <address@hidden> wrote:
> We already implicitly rely on the exception level being
> part of the TB flags for coprocessor access,

Maybe that's the issue? Why not just treat the exception level as
state like any other and generate the TCG to just check it at
execution time?

Regards,
Peter

 so actually
> include it. (This makes no difference for linux-user mode,
> which is always in EL0, but will be needed for correct
> operation in system emulation.)
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  target-arm/cpu.h | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 735f385..1aa4495 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -1051,7 +1051,9 @@ static inline int cpu_mmu_index (CPUARMState *env)
>  #define ARM_TBFLAG_BSWAP_CODE_SHIFT 16
>  #define ARM_TBFLAG_BSWAP_CODE_MASK  (1 << ARM_TBFLAG_BSWAP_CODE_SHIFT)
>
> -/* Bit usage when in AArch64 state: currently no bits defined */
> +/* Bit usage when in AArch64 state */
> +#define ARM_TBFLAG_AA64_EL_SHIFT    0
> +#define ARM_TBFLAG_AA64_EL_MASK     (0x3 << ARM_TBFLAG_AA64_EL_SHIFT)
>
>  /* some convenience accessor macros */
>  #define ARM_TBFLAG_AARCH64_STATE(F) \
> @@ -1070,13 +1072,16 @@ static inline int cpu_mmu_index (CPUARMState *env)
>      (((F) & ARM_TBFLAG_CONDEXEC_MASK) >> ARM_TBFLAG_CONDEXEC_SHIFT)
>  #define ARM_TBFLAG_BSWAP_CODE(F) \
>      (((F) & ARM_TBFLAG_BSWAP_CODE_MASK) >> ARM_TBFLAG_BSWAP_CODE_SHIFT)
> +#define ARM_TBFLAG_AA64_EL(F) \
> +    (((F) & ARM_TBFLAG_AA64_EL_MASK) >> ARM_TBFLAG_AA64_EL_SHIFT)
>
>  static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
>                                          target_ulong *cs_base, int *flags)
>  {
>      if (is_a64(env)) {
>          *pc = env->pc;
> -        *flags = ARM_TBFLAG_AARCH64_STATE_MASK;
> +        *flags = ARM_TBFLAG_AARCH64_STATE_MASK
> +            | arm_current_pl(env) << ARM_TBFLAG_AA64_EL_SHIFT;
>      } else {
>          int privmode;
>          *pc = env->regs[15];
> --
> 1.8.5
>
>