Re: [PATCH v4 18/40] target/arm: Reorganize ARMMMUIdx

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> Prepare for, but do not yet implement, the EL2&0 regime.
> This involves adding the new MMUIdx enumerators and adjusting
> some of the MMUIdx related predicates to match.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  target/arm/cpu-param.h |   2 +-
>  target/arm/cpu.h       | 128 ++++++++++++++++++-----------------------
>  target/arm/internals.h |  37 +++++++++++-
>  target/arm/helper.c    |  66 ++++++++++++++++++---
>  target/arm/translate.c |   1 -
>  5 files changed, 150 insertions(+), 84 deletions(-)
>
> diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h
> index 6e6948e960..18ac562346 100644
> --- a/target/arm/cpu-param.h
> +++ b/target/arm/cpu-param.h
> @@ -29,6 +29,6 @@
>  # define TARGET_PAGE_BITS_MIN  10
>  #endif
>  
> -#define NB_MMU_MODES 8
> +#define NB_MMU_MODES 9
>  
>  #endif
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 015301e93a..bf8eb57e3a 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -2778,7 +2778,9 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx,
>   *  + NonSecure EL1 & 0 stage 1
>   *  + NonSecure EL1 & 0 stage 2
>   *  + NonSecure EL2
> - *  + Secure EL1 & EL0
> + *  + NonSecure EL2 & 0   (ARMv8.1-VHE)
> + *  + Secure EL0
> + *  + Secure EL1
>   *  + Secure EL3
>   * If EL3 is 32-bit:
>   *  + NonSecure PL1 & 0 stage 1
> @@ -2788,8 +2790,9 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx,
>   * (reminder: for 32 bit EL3, Secure PL1 is *EL3*, not EL1.)
>   *
>   * For QEMU, an mmu_idx is not quite the same as a translation regime because:
> - *  1. we need to split the "EL1 & 0" regimes into two mmu_idxes, because they
> - *     may differ in access permissions even if the VA->PA map is the same
> + *  1. we need to split the "EL1 & 0" and "EL2 & 0" regimes into two mmu_idxes,
> + *     because they may differ in access permissions even if the VA->PA map is
> + *     the same
>   *  2. we want to cache in our TLB the full VA->IPA->PA lookup for a stage 1+2
>   *     translation, which means that we have one mmu_idx that deals with two
>   *     concatenated translation regimes [this sort of combined s1+2 TLB is
> @@ -2801,19 +2804,23 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx,
>   *  4. we can also safely fold together the "32 bit EL3" and "64 bit EL3"
>   *     translation regimes, because they map reasonably well to each other
>   *     and they can't both be active at the same time.
> - * This gives us the following list of mmu_idx values:
> + *  5. we want to be able to use the TLB for accesses done as part of a
> + *     stage1 page table walk, rather than having to walk the stage2 page
> + *     table over and over.
>   *
> - * NS EL0 (aka NS PL0) stage 1+2
> - * NS EL1 (aka NS PL1) stage 1+2
> + * This gives us the following list of cases:
> + *
> + * NS EL0 (aka NS PL0) EL1&0 stage 1+2
> + * NS EL1 (aka NS PL1) EL1&0 stage 1+2
> + * NS EL0 EL2&0
> + * NS EL2 EL2&0
>   * NS EL2 (aka NS PL2)
> - * S EL3 (aka S PL1)
>   * S EL0 (aka S PL0)
>   * S EL1 (not used if EL3 is 32 bit)
> - * NS EL0+1 stage 2
> + * S EL3 (aka S PL1)
> + * NS EL0&1 stage 2
>   *
> - * (The last of these is an mmu_idx because we want to be able to use the TLB
> - * for the accesses done as part of a stage 1 page table walk, rather than
> - * having to walk the stage 2 page table over and over.)
> + * for a total of 9 different mmu_idx.
>   *
>   * R profile CPUs have an MPU, but can use the same set of MMU indexes
>   * as A profile. They only need to distinguish NS EL0 and NS EL1 (and
> @@ -2851,26 +2858,47 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx,
>   * For M profile we arrange them to have a bit for priv, a bit for negpri
>   * and a bit for secure.
>   */
> -#define ARM_MMU_IDX_A 0x10 /* A profile */
> -#define ARM_MMU_IDX_NOTLB 0x20 /* does not have a TLB */
> -#define ARM_MMU_IDX_M 0x40 /* M profile */
> +#define ARM_MMU_IDX_A     0x10  /* A profile */
> +#define ARM_MMU_IDX_NOTLB 0x20  /* does not have a TLB */
> +#define ARM_MMU_IDX_M     0x40  /* M profile */
>  
> -/* meanings of the bits for M profile mmu idx values */
> -#define ARM_MMU_IDX_M_PRIV 0x1
> +/* Meanings of the bits for M profile mmu idx values */
> +#define ARM_MMU_IDX_M_PRIV   0x1
>  #define ARM_MMU_IDX_M_NEGPRI 0x2
> -#define ARM_MMU_IDX_M_S 0x4
> +#define ARM_MMU_IDX_M_S      0x4  /* Secure */
>  
> -#define ARM_MMU_IDX_TYPE_MASK (~0x7)
> -#define ARM_MMU_IDX_COREIDX_MASK 0x7
> +#define ARM_MMU_IDX_TYPE_MASK \
> +    (ARM_MMU_IDX_A | ARM_MMU_IDX_M | ARM_MMU_IDX_NOTLB)
> +#define ARM_MMU_IDX_COREIDX_MASK 0xf
>  
>  typedef enum ARMMMUIdx {
> +    /*
> +     * A-profile.
> +     */
>      ARMMMUIdx_EL10_0 = 0 | ARM_MMU_IDX_A,
> -    ARMMMUIdx_EL10_1 = 1 | ARM_MMU_IDX_A,
> -    ARMMMUIdx_E2 = 2 | ARM_MMU_IDX_A,
> -    ARMMMUIdx_SE3 = 3 | ARM_MMU_IDX_A,
> -    ARMMMUIdx_SE0 = 4 | ARM_MMU_IDX_A,
> -    ARMMMUIdx_SE1 = 5 | ARM_MMU_IDX_A,
> -    ARMMMUIdx_Stage2 = 6 | ARM_MMU_IDX_A,
> +    ARMMMUIdx_EL20_0 = 1 | ARM_MMU_IDX_A,
> +
> +    ARMMMUIdx_EL10_1 = 2 | ARM_MMU_IDX_A,
> +
> +    ARMMMUIdx_E2 =     3 | ARM_MMU_IDX_A,
> +    ARMMMUIdx_EL20_2 = 4 | ARM_MMU_IDX_A,
> +
> +    ARMMMUIdx_SE0 =    5 | ARM_MMU_IDX_A,
> +    ARMMMUIdx_SE1 =    6 | ARM_MMU_IDX_A,
> +    ARMMMUIdx_SE3 =    7 | ARM_MMU_IDX_A,
> +
> +    ARMMMUIdx_Stage2 = 8 | ARM_MMU_IDX_A,
> +
> +    /*
> +     * These are not allocated TLBs and are used only for AT system
> +     * instructions or for the first stage of an S12 page table walk.
> +     */
> +    ARMMMUIdx_Stage1_E0 = 0 | ARM_MMU_IDX_NOTLB,
> +    ARMMMUIdx_Stage1_E1 = 1 | ARM_MMU_IDX_NOTLB,
> +
> +    /*
> +     * M-profile.
> +     */
>      ARMMMUIdx_MUser = ARM_MMU_IDX_M,
>      ARMMMUIdx_MPriv = ARM_MMU_IDX_M | ARM_MMU_IDX_M_PRIV,
>      ARMMMUIdx_MUserNegPri = ARMMMUIdx_MUser | ARM_MMU_IDX_M_NEGPRI,
> @@ -2879,11 +2907,6 @@ typedef enum ARMMMUIdx {
>      ARMMMUIdx_MSPriv = ARMMMUIdx_MPriv | ARM_MMU_IDX_M_S,
>      ARMMMUIdx_MSUserNegPri = ARMMMUIdx_MUserNegPri | ARM_MMU_IDX_M_S,
>      ARMMMUIdx_MSPrivNegPri = ARMMMUIdx_MPrivNegPri | ARM_MMU_IDX_M_S,
> -    /* Indexes below here don't have TLBs and are used only for AT system
> -     * instructions or for the first stage of an S12 page table walk.
> -     */
> -    ARMMMUIdx_Stage1_E0 = 0 | ARM_MMU_IDX_NOTLB,
> -    ARMMMUIdx_Stage1_E1 = 1 | ARM_MMU_IDX_NOTLB,
>  } ARMMMUIdx;
>  
>  /*
> @@ -2895,8 +2918,10 @@ typedef enum ARMMMUIdx {
>  
>  typedef enum ARMMMUIdxBit {
>      TO_CORE_BIT(EL10_0),
> +    TO_CORE_BIT(EL20_0),
>      TO_CORE_BIT(EL10_1),
>      TO_CORE_BIT(E2),
> +    TO_CORE_BIT(EL20_2),
>      TO_CORE_BIT(SE0),
>      TO_CORE_BIT(SE1),
>      TO_CORE_BIT(SE3),
> @@ -2916,49 +2941,6 @@ typedef enum ARMMMUIdxBit {
>  
>  #define MMU_USER_IDX 0
>  
> -static inline int arm_to_core_mmu_idx(ARMMMUIdx mmu_idx)
> -{
> -    return mmu_idx & ARM_MMU_IDX_COREIDX_MASK;
> -}
> -
> -static inline ARMMMUIdx core_to_arm_mmu_idx(CPUARMState *env, int mmu_idx)
> -{
> -    if (arm_feature(env, ARM_FEATURE_M)) {
> -        return mmu_idx | ARM_MMU_IDX_M;
> -    } else {
> -        return mmu_idx | ARM_MMU_IDX_A;
> -    }
> -}
> -
> -/* Return the exception level we're running at if this is our mmu_idx */
> -static inline int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx)
> -{
> -    switch (mmu_idx & ARM_MMU_IDX_TYPE_MASK) {
> -    case ARM_MMU_IDX_A:
> -        return mmu_idx & 3;
> -    case ARM_MMU_IDX_M:
> -        return mmu_idx & ARM_MMU_IDX_M_PRIV;
> -    default:
> -        g_assert_not_reached();
> -    }
> -}
> -
> -/*
> - * Return the MMU index for a v7M CPU with all relevant information
> - * manually specified.
> - */
> -ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env,
> -                              bool secstate, bool priv, bool negpri);
> -
> -/* Return the MMU index for a v7M CPU in the specified security and
> - * privilege state.
> - */
> -ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env,
> -                                                bool secstate, bool priv);
> -
> -/* Return the MMU index for a v7M CPU in the specified security state */
> -ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate);
> -
>  /**
>   * cpu_mmu_index:
>   * @env: The cpu environment
> diff --git a/target/arm/internals.h b/target/arm/internals.h
> index aee54dc105..d73615064c 100644
> --- a/target/arm/internals.h
> +++ b/target/arm/internals.h
> @@ -769,6 +769,39 @@ bool arm_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
>                        MMUAccessType access_type, int mmu_idx,
>                        bool probe, uintptr_t retaddr);
>  
> +static inline int arm_to_core_mmu_idx(ARMMMUIdx mmu_idx)
> +{
> +    return mmu_idx & ARM_MMU_IDX_COREIDX_MASK;
> +}
> +
> +static inline ARMMMUIdx core_to_arm_mmu_idx(CPUARMState *env, int mmu_idx)
> +{
> +    if (arm_feature(env, ARM_FEATURE_M)) {
> +        return mmu_idx | ARM_MMU_IDX_M;
> +    } else {
> +        return mmu_idx | ARM_MMU_IDX_A;
> +    }
> +}
> +
> +int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx);
> +
> +/*
> + * Return the MMU index for a v7M CPU with all relevant information
> + * manually specified.
> + */
> +ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env,
> +                              bool secstate, bool priv, bool negpri);
> +
> +/*
> + * Return the MMU index for a v7M CPU in the specified security and
> + * privilege state.
> + */
> +ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env,
> +                                                bool secstate, bool priv);
> +
> +/* Return the MMU index for a v7M CPU in the specified security state */
> +ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate);
> +
>  /* Return true if the stage 1 translation regime is using LPAE format page
>   * tables */
>  bool arm_s1_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx);
> @@ -810,6 +843,8 @@ static inline bool regime_is_secure(CPUARMState *env, ARMMMUIdx mmu_idx)
>      switch (mmu_idx) {
>      case ARMMMUIdx_EL10_0:
>      case ARMMMUIdx_EL10_1:
> +    case ARMMMUIdx_EL20_0:
> +    case ARMMMUIdx_EL20_2:
>      case ARMMMUIdx_Stage1_E0:
>      case ARMMMUIdx_Stage1_E1:
>      case ARMMMUIdx_E2:
> @@ -819,9 +854,9 @@ static inline bool regime_is_secure(CPUARMState *env, ARMMMUIdx mmu_idx)
>      case ARMMMUIdx_MPriv:
>      case ARMMMUIdx_MUser:
>          return false;
> -    case ARMMMUIdx_SE3:
>      case ARMMMUIdx_SE0:
>      case ARMMMUIdx_SE1:
> +    case ARMMMUIdx_SE3:
>      case ARMMMUIdx_MSPrivNegPri:
>      case ARMMMUIdx_MSUserNegPri:
>      case ARMMMUIdx_MSPriv:
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index ec5c7fa325..f86285ffbe 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -8561,9 +8561,11 @@ void arm_cpu_do_interrupt(CPUState *cs)
>  #endif /* !CONFIG_USER_ONLY */
>  
>  /* Return the exception level which controls this address translation regime */
> -static inline uint32_t regime_el(CPUARMState *env, ARMMMUIdx mmu_idx)
> +static uint32_t regime_el(CPUARMState *env, ARMMMUIdx mmu_idx)
>  {
>      switch (mmu_idx) {
> +    case ARMMMUIdx_EL20_0:
> +    case ARMMMUIdx_EL20_2:
>      case ARMMMUIdx_Stage2:
>      case ARMMMUIdx_E2:
>          return 2;
> @@ -8574,6 +8576,8 @@ static inline uint32_t regime_el(CPUARMState *env, ARMMMUIdx mmu_idx)
>      case ARMMMUIdx_SE1:
>      case ARMMMUIdx_Stage1_E0:
>      case ARMMMUIdx_Stage1_E1:
> +    case ARMMMUIdx_EL10_0:
> +    case ARMMMUIdx_EL10_1:
>      case ARMMMUIdx_MPrivNegPri:
>      case ARMMMUIdx_MUserNegPri:
>      case ARMMMUIdx_MPriv:
> @@ -8675,10 +8679,14 @@ static inline TCR *regime_tcr(CPUARMState *env, ARMMMUIdx mmu_idx)
>   */
>  static inline ARMMMUIdx stage_1_mmu_idx(ARMMMUIdx mmu_idx)
>  {
> -    if (mmu_idx == ARMMMUIdx_EL10_0 || mmu_idx == ARMMMUIdx_EL10_1) {
> -        mmu_idx += (ARMMMUIdx_Stage1_E0 - ARMMMUIdx_EL10_0);
> +    switch (mmu_idx) {
> +    case ARMMMUIdx_EL10_0:
> +        return ARMMMUIdx_Stage1_E0;
> +    case ARMMMUIdx_EL10_1:
> +        return ARMMMUIdx_Stage1_E1;
> +    default:
> +        return mmu_idx;
>      }
> -    return mmu_idx;
>  }
>  
>  /* Return true if the translation regime is using LPAE format page tables */
> @@ -8711,6 +8719,7 @@ static inline bool regime_is_user(CPUARMState *env, ARMMMUIdx mmu_idx)
>  {
>      switch (mmu_idx) {
>      case ARMMMUIdx_SE0:
> +    case ARMMMUIdx_EL20_0:
>      case ARMMMUIdx_Stage1_E0:
>      case ARMMMUIdx_MUser:
>      case ARMMMUIdx_MSUser:
> @@ -11136,6 +11145,31 @@ int fp_exception_el(CPUARMState *env, int cur_el)
>      return 0;
>  }
>  
> +/* Return the exception level we're running at if this is our mmu_idx */
> +int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx)
> +{
> +    if (mmu_idx & ARM_MMU_IDX_M) {
> +        return mmu_idx & ARM_MMU_IDX_M_PRIV;
> +    }
> +
> +    switch (mmu_idx) {
> +    case ARMMMUIdx_EL10_0:
> +    case ARMMMUIdx_EL20_0:
> +    case ARMMMUIdx_SE0:
> +        return 0;
> +    case ARMMMUIdx_EL10_1:
> +    case ARMMMUIdx_SE1:
> +        return 1;
> +    case ARMMMUIdx_E2:
> +    case ARMMMUIdx_EL20_2:
> +        return 2;
> +    case ARMMMUIdx_SE3:
> +        return 3;
> +    default:
> +        g_assert_not_reached();
> +    }
> +}
> +
>  #ifndef CONFIG_TCG
>  ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate)
>  {
> @@ -11149,10 +11183,26 @@ ARMMMUIdx arm_mmu_idx_el(CPUARMState *env, int el)
>          return arm_v7m_mmu_idx_for_secstate(env, env->v7m.secure);
>      }
>  
> -    if (el < 2 && arm_is_secure_below_el3(env)) {
> -        return ARMMMUIdx_SE0 + el;
> -    } else {
> -        return ARMMMUIdx_EL10_0 + el;
> +    switch (el) {
> +    case 0:
> +        /* TODO: ARMv8.1-VHE */
> +        if (arm_is_secure_below_el3(env)) {
> +            return ARMMMUIdx_SE0;
> +        }
> +        return ARMMMUIdx_EL10_0;
> +    case 1:
> +        if (arm_is_secure_below_el3(env)) {
> +            return ARMMMUIdx_SE1;
> +        }
> +        return ARMMMUIdx_EL10_1;
> +    case 2:
> +        /* TODO: ARMv8.1-VHE */
> +        /* TODO: ARMv8.4-SecEL2 */
> +        return ARMMMUIdx_E2;
> +    case 3:
> +        return ARMMMUIdx_SE3;
> +    default:
> +        g_assert_not_reached();
>      }
>  }
>  
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index cd757165e1..b7f726e733 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -172,7 +172,6 @@ static inline int get_a32_user_mem_index(DisasContext *s)
>      case ARMMMUIdx_MSUserNegPri:
>      case ARMMMUIdx_MSPrivNegPri:
>          return arm_to_core_mmu_idx(ARMMMUIdx_MSUserNegPri);
> -    case ARMMMUIdx_Stage2:
>      default:
>          g_assert_not_reached();
>      }


-- 
Alex Bennée