Re: [PATCH v13 6/7] target/riscv: Apply pointer masking for virtualized memory accesses

[Alexey Baturo]

Hi Alistair,

Thanks for the review. I've tried to address your comments and submitted a new version.

Could you please take a look if it's ok with you and if so, could you please put these patches to the queue for the next qemu update?

Thanks!

вт, 17 дек. 2024 г. в 09:13, Alistair Francis <alistair23@gmail.com>:

On Mon, Dec 16, 2024 at 10:19 PM <baturo.alexey@gmail.com> wrote:
>
> From: Alexey Baturo <baturo.alexey@gmail.com>
>
> Signed-off-by: Alexey Baturo <baturo.alexey@gmail.com>
> ---
>  target/riscv/cpu.h           |  1 +
>  target/riscv/cpu_helper.c    | 18 +++++++++++++++
>  target/riscv/internals.h     | 44 ++++++++++++++++++++++++++++++++++++
>  target/riscv/op_helper.c     | 16 ++++++-------
>  target/riscv/vector_helper.c | 21 -----------------
>  5 files changed, 71 insertions(+), 29 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 38231fe21e..536ad20fdd 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -773,6 +773,7 @@ bool riscv_cpu_is_32bit(RISCVCPU *cpu);
>
>  bool riscv_cpu_virt_mem_enabled(CPURISCVState *env);
>  RISCVPmPmm riscv_pm_get_pmm(CPURISCVState *env);
> +RISCVPmPmm riscv_pm_get_virt_pmm(CPURISCVState *env);
>  uint32_t riscv_pm_get_pmlen(RISCVPmPmm pmm);
>
>  RISCVException riscv_csrr(CPURISCVState *env, int csrno,
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 480d2c2c8b..471d8d40a1 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -260,6 +260,24 @@ RISCVPmPmm riscv_pm_get_pmm(CPURISCVState *env)
>      return pmm;
>  }
>
> +RISCVPmPmm riscv_pm_get_virt_pmm(CPURISCVState *env)
> +{
> +    RISCVPmPmm pmm = PMM_FIELD_DISABLED;
> +#ifndef CONFIG_USER_ONLY
> +    int priv_mode = cpu_address_mode(env);
> +    if (priv_mode == PRV_U) {
> +        pmm = get_field(env->hstatus, HSTATUS_HUPMM);
> +    } else {
> +        if (get_field(env->hstatus, HSTATUS_SPVP)) {
> +            pmm = get_field(env->henvcfg, HENVCFG_PMM);
> +        } else {
> +            pmm = get_field(env->senvcfg, SENVCFG_PMM);
> +        }
> +    }
> +#endif
> +    return pmm;
> +}
> +
>  bool riscv_cpu_virt_mem_enabled(CPURISCVState *env)
>  {
>      bool virt_mem_en = false;
> diff --git a/target/riscv/internals.h b/target/riscv/internals.h
> index ddbdee885b..017f33af1f 100644
> --- a/target/riscv/internals.h
> +++ b/target/riscv/internals.h
> @@ -142,4 +142,48 @@ static inline float16 check_nanbox_h(CPURISCVState *env, uint64_t f)
>  /* Our implementation of CPUClass::has_work */
>  bool riscv_cpu_has_work(CPUState *cs);
>
> +/* Zjpm addr masking routine */
> +static inline target_ulong adjust_addr_body(CPURISCVState *env,
> +                                            target_ulong addr,
> +                                            bool is_virt)

Maybe is_virt_addr to be clear it's an address and not hypervisor virtulisation.

> +{
> +    if (riscv_cpu_mxl(env) == MXL_RV32) {
> +        return addr;
> +    }
> +    RISCVPmPmm pmm = PMM_FIELD_DISABLED;

Same comment about mixed code and declarations and some newlines would
be great :)

> +    if (is_virt) {
> +        pmm = riscv_pm_get_virt_pmm(env);
> +    } else {
> +        pmm = riscv_pm_get_pmm(env);
> +    }
> +    if (pmm == PMM_FIELD_DISABLED) {
> +        return addr;
> +    }
> +    uint32_t pmlen = riscv_pm_get_pmlen(pmm);
> +    bool signext = false;
> +    if (!is_virt) {
> +        signext = riscv_cpu_virt_mem_enabled(env);
> +    }
> +    addr = addr << pmlen;
> +    /* sign/zero extend masked address by N-1 bit */
> +    if (signext) {
> +        addr = (target_long)addr >> pmlen;
> +    } else {
> +        addr = addr >> pmlen;
> +    }
> +    return addr;
> +}
> +
> +static inline target_ulong adjust_addr(CPURISCVState *env,
> +                                       target_ulong addr)
> +{
> +    return adjust_addr_body(env, addr, false);
> +}
> +
> +static inline target_ulong adjust_addr_virt(CPURISCVState *env,
> +                                            target_ulong addr)
> +{
> +    return adjust_addr_body(env, addr, true);
> +}

Otherwise looks good

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> +
>  #endif
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index eddedacf4b..20e5bd5088 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -472,7 +472,7 @@ target_ulong helper_hyp_hlv_bu(CPURISCVState *env, target_ulong addr)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_UB, mmu_idx);
>
> -    return cpu_ldb_mmu(env, addr, oi, ra);
> +    return cpu_ldb_mmu(env, adjust_addr_virt(env, addr), oi, ra);
>  }
>
>  target_ulong helper_hyp_hlv_hu(CPURISCVState *env, target_ulong addr)
> @@ -481,7 +481,7 @@ target_ulong helper_hyp_hlv_hu(CPURISCVState *env, target_ulong addr)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_TEUW, mmu_idx);
>
> -    return cpu_ldw_mmu(env, addr, oi, ra);
> +    return cpu_ldw_mmu(env, adjust_addr_virt(env, addr), oi, ra);
>  }
>
>  target_ulong helper_hyp_hlv_wu(CPURISCVState *env, target_ulong addr)
> @@ -490,7 +490,7 @@ target_ulong helper_hyp_hlv_wu(CPURISCVState *env, target_ulong addr)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_TEUL, mmu_idx);
>
> -    return cpu_ldl_mmu(env, addr, oi, ra);
> +    return cpu_ldl_mmu(env, adjust_addr_virt(env, addr), oi, ra);
>  }
>
>  target_ulong helper_hyp_hlv_d(CPURISCVState *env, target_ulong addr)
> @@ -499,7 +499,7 @@ target_ulong helper_hyp_hlv_d(CPURISCVState *env, target_ulong addr)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_TEUQ, mmu_idx);
>
> -    return cpu_ldq_mmu(env, addr, oi, ra);
> +    return cpu_ldq_mmu(env, adjust_addr_virt(env, addr), oi, ra);
>  }
>
>  void helper_hyp_hsv_b(CPURISCVState *env, target_ulong addr, target_ulong val)
> @@ -508,7 +508,7 @@ void helper_hyp_hsv_b(CPURISCVState *env, target_ulong addr, target_ulong val)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_UB, mmu_idx);
>
> -    cpu_stb_mmu(env, addr, val, oi, ra);
> +    cpu_stb_mmu(env, adjust_addr_virt(env, addr), val, oi, ra);
>  }
>
>  void helper_hyp_hsv_h(CPURISCVState *env, target_ulong addr, target_ulong val)
> @@ -517,7 +517,7 @@ void helper_hyp_hsv_h(CPURISCVState *env, target_ulong addr, target_ulong val)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_TEUW, mmu_idx);
>
> -    cpu_stw_mmu(env, addr, val, oi, ra);
> +    cpu_stw_mmu(env, adjust_addr_virt(env, addr), val, oi, ra);
>  }
>
>  void helper_hyp_hsv_w(CPURISCVState *env, target_ulong addr, target_ulong val)
> @@ -526,7 +526,7 @@ void helper_hyp_hsv_w(CPURISCVState *env, target_ulong addr, target_ulong val)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_TEUL, mmu_idx);
>
> -    cpu_stl_mmu(env, addr, val, oi, ra);
> +    cpu_stl_mmu(env, adjust_addr_virt(env, addr), val, oi, ra);
>  }
>
>  void helper_hyp_hsv_d(CPURISCVState *env, target_ulong addr, target_ulong val)
> @@ -535,7 +535,7 @@ void helper_hyp_hsv_d(CPURISCVState *env, target_ulong addr, target_ulong val)
>      int mmu_idx = check_access_hlsv(env, false, ra);
>      MemOpIdx oi = make_memop_idx(MO_TEUQ, mmu_idx);
>
> -    cpu_stq_mmu(env, addr, val, oi, ra);
> +    cpu_stq_mmu(env, adjust_addr_virt(env, addr), val, oi, ra);
>  }
>
>  /*
> diff --git a/target/riscv/vector_helper.c b/target/riscv/vector_helper.c
> index 37c6c198a5..a0093bcc9c 100644
> --- a/target/riscv/vector_helper.c
> +++ b/target/riscv/vector_helper.c
> @@ -105,27 +105,6 @@ static inline uint32_t vext_max_elems(uint32_t desc, uint32_t log2_esz)
>      return scale < 0 ? vlenb >> -scale : vlenb << scale;
>  }
>
> -static inline target_ulong adjust_addr(CPURISCVState *env, target_ulong addr)
> -{
> -    if (riscv_cpu_mxl(env) == MXL_RV32) {
> -        return addr;
> -    }
> -    RISCVPmPmm pmm = riscv_pm_get_pmm(env);
> -    if (pmm == PMM_FIELD_DISABLED) {
> -        return addr;
> -    }
> -    int pmlen = riscv_pm_get_pmlen(pmm);
> -    bool signext = riscv_cpu_virt_mem_enabled(env);
> -    addr = addr << pmlen;
> -    /* sign/zero extend masked address by N-1 bit */
> -    if (signext) {
> -        addr = (target_long)addr >> pmlen;
> -    } else {
> -        addr = addr >> pmlen;
> -    }
> -    return addr;
> -}
> -
>  /*
>   * This function checks watchpoint before real load operation.
>   *
> --
> 2.39.5
>