diff mbox series

[v7,1/5] target/riscv: Ignore reserved bits in PTE for RV64

Message ID 20220128085501.8014-2-liweiwei@iscas.ac.cn (mailing list archive)
State New, archived
Headers show
Series support subsets of virtual memory extension | expand

Commit Message

Weiwei Li Jan. 28, 2022, 8:54 a.m. UTC 
From: Guo Ren <ren_guo@c-sky.com>

Highest bits of PTE has been used for svpbmt, ref: [1], [2], so we
need to ignore them. They cannot be a part of ppn.

1: The RISC-V Instruction Set Manual, Volume II: Privileged Architecture
   4.4 Sv39: Page-Based 39-bit Virtual-Memory System
   4.5 Sv48: Page-Based 48-bit Virtual-Memory System

2: https://github.com/riscv/virtual-memory/blob/main/specs/663-Svpbmt-diff.pdf

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h        | 15 +++++++++++++++
 target/riscv/cpu_bits.h   |  3 +++
 target/riscv/cpu_helper.c | 14 +++++++++++++-
 3 files changed, 31 insertions(+), 1 deletion(-)

Comments

Alistair Francis Feb. 1, 2022, 3:31 a.m. UTC | #1 
On Fri, Jan 28, 2022 at 7:11 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
> From: Guo Ren <ren_guo@c-sky.com>
>
> Highest bits of PTE has been used for svpbmt, ref: [1], [2], so we
> need to ignore them. They cannot be a part of ppn.
>
> 1: The RISC-V Instruction Set Manual, Volume II: Privileged Architecture
>    4.4 Sv39: Page-Based 39-bit Virtual-Memory System
>    4.5 Sv48: Page-Based 48-bit Virtual-Memory System
>
> 2: https://github.com/riscv/virtual-memory/blob/main/specs/663-Svpbmt-diff.pdf
>
> Signed-off-by: Guo Ren <ren_guo@c-sky.com>
> Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
> Cc: Bin Meng <bmeng.cn@gmail.com>
> Cc: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.h        | 15 +++++++++++++++
>  target/riscv/cpu_bits.h   |  3 +++
>  target/riscv/cpu_helper.c | 14 +++++++++++++-
>  3 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 55635d68d5..336fe8e3d5 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -341,6 +341,8 @@ struct RISCVCPU {
>          bool ext_counters;
>          bool ext_ifencei;
>          bool ext_icsr;
> +        bool ext_svnapot;
> +        bool ext_svpbmt;
>          bool ext_zfh;
>          bool ext_zfhmin;
>          bool ext_zve32f;

Hello, thanks for the patches.

This looks good, but you might need to rebase it as there are patches
on list that move this into a different struct.

> @@ -495,6 +497,19 @@ static inline int riscv_cpu_xlen(CPURISCVState *env)
>      return 16 << env->xl;
>  }
>
> +#ifdef TARGET_RISCV32
> +#define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
> +#else
> +static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
> +{
> +#ifdef CONFIG_USER_ONLY
> +    return env->misa_mxl;
> +#else
> +    return get_field(env->mstatus, MSTATUS64_SXL);
> +#endif
> +}
> +#endif
> +
>  /*
>   * Encode LMUL to lmul as follows:
>   *     LMUL    vlmul    lmul
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 7c87433645..6ea3944423 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -493,6 +493,9 @@ typedef enum {
>  /* Page table PPN shift amount */
>  #define PTE_PPN_SHIFT       10
>
> +/* Page table PPN mask */
> +#define PTE_PPN_MASK        0x3FFFFFFFFFFC00ULL
> +
>  /* Leaf page shift amount */
>  #define PGSHIFT             12
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 327a2c4f1d..5a1c0e239e 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -622,7 +622,19 @@ restart:
>              return TRANSLATE_FAIL;
>          }
>
> -        hwaddr ppn = pte >> PTE_PPN_SHIFT;
> +        hwaddr ppn;
> +        RISCVCPU *cpu = env_archcpu(env);

I know there is existing code in this function that does this, but
please don't initiate variables mid function. Can you move this to the
top of the function?

Otherwise:

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

Alistair

> +
> +        if (riscv_cpu_sxl(env) == MXL_RV32) {
> +            ppn = pte >> PTE_PPN_SHIFT;
> +        } else if (cpu->cfg.ext_svpbmt || cpu->cfg.ext_svnapot) {
> +            ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
> +        } else {
> +            ppn = pte >> PTE_PPN_SHIFT;
> +            if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
> +                return TRANSLATE_FAIL;
> +            }
> +        }
>
>          if (!(pte & PTE_V)) {
>              /* Invalid PTE */
> --
> 2.17.1
>
>
Weiwei Li Feb. 1, 2022, 12:55 p.m. UTC | #2 
在 2022/2/1 上午11:31, Alistair Francis 写道:
> On Fri, Jan 28, 2022 at 7:11 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>> From: Guo Ren <ren_guo@c-sky.com>
>>
>> Highest bits of PTE has been used for svpbmt, ref: [1], [2], so we
>> need to ignore them. They cannot be a part of ppn.
>>
>> 1: The RISC-V Instruction Set Manual, Volume II: Privileged Architecture
>>     4.4 Sv39: Page-Based 39-bit Virtual-Memory System
>>     4.5 Sv48: Page-Based 48-bit Virtual-Memory System
>>
>> 2: https://github.com/riscv/virtual-memory/blob/main/specs/663-Svpbmt-diff.pdf
>>
>> Signed-off-by: Guo Ren <ren_guo@c-sky.com>
>> Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
>> Cc: Bin Meng <bmeng.cn@gmail.com>
>> Cc: Alistair Francis <alistair.francis@wdc.com>
>> ---
>>   target/riscv/cpu.h        | 15 +++++++++++++++
>>   target/riscv/cpu_bits.h   |  3 +++
>>   target/riscv/cpu_helper.c | 14 +++++++++++++-
>>   3 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
>> index 55635d68d5..336fe8e3d5 100644
>> --- a/target/riscv/cpu.h
>> +++ b/target/riscv/cpu.h
>> @@ -341,6 +341,8 @@ struct RISCVCPU {
>>           bool ext_counters;
>>           bool ext_ifencei;
>>           bool ext_icsr;
>> +        bool ext_svnapot;
>> +        bool ext_svpbmt;
>>           bool ext_zfh;
>>           bool ext_zfhmin;
>>           bool ext_zve32f;
> Hello, thanks for the patches.
>
> This looks good, but you might need to rebase it as there are patches
> on list that move this into a different struct.

Thanks for your review.

I'll rebase it.

>
>> @@ -495,6 +497,19 @@ static inline int riscv_cpu_xlen(CPURISCVState *env)
>>       return 16 << env->xl;
>>   }
>>
>> +#ifdef TARGET_RISCV32
>> +#define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
>> +#else
>> +static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
>> +{
>> +#ifdef CONFIG_USER_ONLY
>> +    return env->misa_mxl;
>> +#else
>> +    return get_field(env->mstatus, MSTATUS64_SXL);
>> +#endif
>> +}
>> +#endif
>> +
>>   /*
>>    * Encode LMUL to lmul as follows:
>>    *     LMUL    vlmul    lmul
>> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
>> index 7c87433645..6ea3944423 100644
>> --- a/target/riscv/cpu_bits.h
>> +++ b/target/riscv/cpu_bits.h
>> @@ -493,6 +493,9 @@ typedef enum {
>>   /* Page table PPN shift amount */
>>   #define PTE_PPN_SHIFT       10
>>
>> +/* Page table PPN mask */
>> +#define PTE_PPN_MASK        0x3FFFFFFFFFFC00ULL
>> +
>>   /* Leaf page shift amount */
>>   #define PGSHIFT             12
>>
>> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
>> index 327a2c4f1d..5a1c0e239e 100644
>> --- a/target/riscv/cpu_helper.c
>> +++ b/target/riscv/cpu_helper.c
>> @@ -622,7 +622,19 @@ restart:
>>               return TRANSLATE_FAIL;
>>           }
>>
>> -        hwaddr ppn = pte >> PTE_PPN_SHIFT;
>> +        hwaddr ppn;
>> +        RISCVCPU *cpu = env_archcpu(env);
> I know there is existing code in this function that does this, but
> please don't initiate variables mid function. Can you move this to the
> top of the function?
OK.
>
> Otherwise:
>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
>
> Alistair
>
>> +
>> +        if (riscv_cpu_sxl(env) == MXL_RV32) {
>> +            ppn = pte >> PTE_PPN_SHIFT;
>> +        } else if (cpu->cfg.ext_svpbmt || cpu->cfg.ext_svnapot) {
>> +            ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
>> +        } else {
>> +            ppn = pte >> PTE_PPN_SHIFT;
>> +            if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
>> +                return TRANSLATE_FAIL;
>> +            }
>> +        }
>>
>>           if (!(pte & PTE_V)) {
>>               /* Invalid PTE */
>> --
>> 2.17.1
>>
>>
diff mbox series

Patch

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 55635d68d5..336fe8e3d5 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -341,6 +341,8 @@  struct RISCVCPU {
         bool ext_counters;
         bool ext_ifencei;
         bool ext_icsr;
+        bool ext_svnapot;
+        bool ext_svpbmt;
         bool ext_zfh;
         bool ext_zfhmin;
         bool ext_zve32f;
@@ -495,6 +497,19 @@  static inline int riscv_cpu_xlen(CPURISCVState *env)
     return 16 << env->xl;
 }
 
+#ifdef TARGET_RISCV32
+#define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
+#else
+static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
+{
+#ifdef CONFIG_USER_ONLY
+    return env->misa_mxl;
+#else
+    return get_field(env->mstatus, MSTATUS64_SXL);
+#endif
+}
+#endif
+
 /*
  * Encode LMUL to lmul as follows:
  *     LMUL    vlmul    lmul
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 7c87433645..6ea3944423 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -493,6 +493,9 @@  typedef enum {
 /* Page table PPN shift amount */
 #define PTE_PPN_SHIFT       10
 
+/* Page table PPN mask */
+#define PTE_PPN_MASK        0x3FFFFFFFFFFC00ULL
+
 /* Leaf page shift amount */
 #define PGSHIFT             12
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 327a2c4f1d..5a1c0e239e 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -622,7 +622,19 @@  restart:
             return TRANSLATE_FAIL;
         }
 
-        hwaddr ppn = pte >> PTE_PPN_SHIFT;
+        hwaddr ppn;
+        RISCVCPU *cpu = env_archcpu(env);
+
+        if (riscv_cpu_sxl(env) == MXL_RV32) {
+            ppn = pte >> PTE_PPN_SHIFT;
+        } else if (cpu->cfg.ext_svpbmt || cpu->cfg.ext_svnapot) {
+            ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
+        } else {
+            ppn = pte >> PTE_PPN_SHIFT;
+            if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
+                return TRANSLATE_FAIL;
+            }
+        }
 
         if (!(pte & PTE_V)) {
             /* Invalid PTE */