[v1] Pointer Masking update for Zjpm v1.0

[PATCH 2/7] target/riscv: Add new CSR fields for S{sn, mn, m}pm extensions as part of Zjpm v1.0

Posted by baturo.alexey@gmail.com 2 weeks, 1 day ago

From: Alexey Baturo <baturo.alexey@gmail.com>

Signed-off-by: Alexey Baturo <baturo.alexey@gmail.com>
---
 target/riscv/cpu.h      |  8 ++++++++
 target/riscv/cpu_bits.h |  4 ++++
 target/riscv/cpu_cfg.h  |  3 +++
 target/riscv/csr.c      | 30 ++++++++++++++++++++++++++++++
 target/riscv/pmp.c      | 14 +++++++++++---
 target/riscv/pmp.h      |  1 +
 6 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index e11264231d..417ff45544 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -128,6 +128,14 @@ typedef enum {
     EXT_STATUS_DIRTY,
 } RISCVExtStatus;
 
+/* Enum holds PMM field values for Zjpm v1.0 extension */
+typedef enum {
+    PMM_FIELD_DISABLED = 0,
+    PMM_FIELD_RESERVED = 1,
+    PMM_FIELD_PMLEN7   = 2,
+    PMM_FIELD_PMLEN16  = 3,
+} RISCVPmPmm;
+
 typedef struct riscv_cpu_implied_exts_rule {
 #ifndef CONFIG_USER_ONLY
     /*
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 2a6aff63ed..d8f9bc68e3 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -574,6 +574,7 @@ typedef enum {
 #define HSTATUS_VTW          0x00200000
 #define HSTATUS_VTSR         0x00400000
 #define HSTATUS_VSXL         0x300000000
+#define HSTATUS_HUPMM        0x3000000000000
 
 #define HSTATUS32_WPRI       0xFF8FF87E
 #define HSTATUS64_WPRI       0xFFFFFFFFFF8FF87EULL
@@ -734,6 +735,7 @@ typedef enum RISCVException {
 #define MENVCFG_CBIE                       (3UL << 4)
 #define MENVCFG_CBCFE                      BIT(6)
 #define MENVCFG_CBZE                       BIT(7)
+#define MENVCFG_PMM                        (3ULL << 32)
 #define MENVCFG_ADUE                       (1ULL << 61)
 #define MENVCFG_PBMTE                      (1ULL << 62)
 #define MENVCFG_STCE                       (1ULL << 63)
@@ -749,6 +751,7 @@ typedef enum RISCVException {
 #define SENVCFG_CBIE                       MENVCFG_CBIE
 #define SENVCFG_CBCFE                      MENVCFG_CBCFE
 #define SENVCFG_CBZE                       MENVCFG_CBZE
+#define SENVCFG_PMM                        MENVCFG_PMM
 
 #define HENVCFG_FIOM                       MENVCFG_FIOM
 #define HENVCFG_LPE                        MENVCFG_LPE
@@ -756,6 +759,7 @@ typedef enum RISCVException {
 #define HENVCFG_CBIE                       MENVCFG_CBIE
 #define HENVCFG_CBCFE                      MENVCFG_CBCFE
 #define HENVCFG_CBZE                       MENVCFG_CBZE
+#define HENVCFG_PMM                        MENVCFG_PMM
 #define HENVCFG_ADUE                       MENVCFG_ADUE
 #define HENVCFG_PBMTE                      MENVCFG_PBMTE
 #define HENVCFG_STCE                       MENVCFG_STCE
diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h
index 59d6fc445d..79a114eb07 100644
--- a/target/riscv/cpu_cfg.h
+++ b/target/riscv/cpu_cfg.h
@@ -128,6 +128,9 @@ struct RISCVCPUConfig {
     bool ext_ssaia;
     bool ext_sscofpmf;
     bool ext_smepmp;
+    bool ext_ssnpm;
+    bool ext_smnpm;
+    bool ext_smmpm;
     bool rvv_ta_all_1s;
     bool rvv_ma_all_1s;
     bool rvv_vl_half_avl;
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 941c9691da..af4cc83341 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -575,6 +575,9 @@ static RISCVException have_mseccfg(CPURISCVState *env, int csrno)
     if (riscv_cpu_cfg(env)->ext_zkr) {
         return RISCV_EXCP_NONE;
     }
+    if (riscv_cpu_cfg(env)->ext_smmpm) {
+        return RISCV_EXCP_NONE;
+    }
 
     return RISCV_EXCP_ILLEGAL_INST;
 }
@@ -2379,6 +2382,12 @@ static RISCVException write_menvcfg(CPURISCVState *env, int csrno,
         if (env_archcpu(env)->cfg.ext_zicfiss) {
             mask |= MENVCFG_SSE;
         }
+
+        /* Update PMM field only if the value is valid according to Zjpm v1.0 */
+        if (env_archcpu(env)->cfg.ext_smnpm &&
+            (get_field(val, MENVCFG_PMM) != PMM_FIELD_RESERVED)) {
+            mask |= MENVCFG_PMM;
+        }
     }
     env->menvcfg = (env->menvcfg & ~mask) | (val & mask);
 
@@ -2424,6 +2433,12 @@ static RISCVException write_senvcfg(CPURISCVState *env, int csrno,
                                     target_ulong val)
 {
     uint64_t mask = SENVCFG_FIOM | SENVCFG_CBIE | SENVCFG_CBCFE | SENVCFG_CBZE;
+    /* Update PMM field only if the value is valid according to Zjpm v1.0 */
+    if (env_archcpu(env)->cfg.ext_ssnpm &&
+        riscv_cpu_mxl(env) == MXL_RV64 &&
+        (get_field(val, SENVCFG_PMM) != PMM_FIELD_RESERVED)) {
+        mask |= SENVCFG_PMM;
+    }
     RISCVException ret;
 
     ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
@@ -2489,6 +2504,12 @@ static RISCVException write_henvcfg(CPURISCVState *env, int csrno,
             get_field(env->menvcfg, MENVCFG_SSE)) {
             mask |= HENVCFG_SSE;
         }
+
+        /* Update PMM field only if the value is valid according to Zjpm v1.0 */
+        if (env_archcpu(env)->cfg.ext_ssnpm &&
+            (get_field(val, HENVCFG_PMM) != PMM_FIELD_RESERVED)) {
+            mask |= HENVCFG_PMM;
+        }
     }
 
     env->henvcfg = (env->henvcfg & ~mask) | (val & mask);
@@ -3525,6 +3546,15 @@ static RISCVException read_hstatus(CPURISCVState *env, int csrno,
 static RISCVException write_hstatus(CPURISCVState *env, int csrno,
                                     target_ulong val)
 {
+    uint64_t mask = (target_ulong)-1;
+    /* Update PMM field only if the value is valid according to Zjpm v1.0 */
+    if (env_archcpu(env)->cfg.ext_ssnpm &&
+        (riscv_cpu_mxl(env) == MXL_RV64) &&
+        (get_field(val, HSTATUS_HUPMM) == PMM_FIELD_RESERVED)) {
+        mask &= ~HSTATUS_HUPMM;
+    }
+    env->hstatus = (env->hstatus & ~mask) | (val & mask);
+
     env->hstatus = val;
     if (riscv_cpu_mxl(env) != MXL_RV32 && get_field(val, HSTATUS_VSXL) != 2) {
         qemu_log_mask(LOG_UNIMP,
diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index a1b36664fc..cc4cc05d9e 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -575,6 +575,13 @@ target_ulong pmpaddr_csr_read(CPURISCVState *env, uint32_t addr_index)
 void mseccfg_csr_write(CPURISCVState *env, target_ulong val)
 {
     int i;
+    uint64_t mask = MSECCFG_MMWP | MSECCFG_MML;
+    /* Update PMM field only if the value is valid according to Zjpm v1.0 */
+    if (riscv_cpu_cfg(env)->ext_smmpm &&
+        riscv_cpu_mxl(env) == MXL_RV64 &&
+        (get_field(val, MSECCFG_PMM) != PMM_FIELD_RESERVED)) {
+        mask |= MSECCFG_PMM;
+    }
 
     trace_mseccfg_csr_write(env->mhartid, val);
 
@@ -590,12 +597,13 @@ void mseccfg_csr_write(CPURISCVState *env, target_ulong val)
 
     if (riscv_cpu_cfg(env)->ext_smepmp) {
         /* Sticky bits */
-        val |= (env->mseccfg & (MSECCFG_MMWP | MSECCFG_MML));
-        if ((val ^ env->mseccfg) & (MSECCFG_MMWP | MSECCFG_MML)) {
+        val |= (env->mseccfg & mask);
+        if ((val ^ env->mseccfg) & mask) {
             tlb_flush(env_cpu(env));
         }
     } else {
-        val &= ~(MSECCFG_MMWP | MSECCFG_MML | MSECCFG_RLB);
+        mask |= MSECCFG_RLB;
+        val &= ~(mask);
     }
 
     /* M-mode forward cfi to be enabled if cfi extension is implemented */
diff --git a/target/riscv/pmp.h b/target/riscv/pmp.h
index e0530a17a3..271cf24169 100644
--- a/target/riscv/pmp.h
+++ b/target/riscv/pmp.h
@@ -46,6 +46,7 @@ typedef enum {
     MSECCFG_USEED = 1 << 8,
     MSECCFG_SSEED = 1 << 9,
     MSECCFG_MLPE =  1 << 10,
+    MSECCFG_PMM = 3ULL << 32,
 } mseccfg_field_t;
 
 typedef struct {
-- 
2.39.5

Re: [PATCH 2/7] target/riscv: Add new CSR fields for S{sn,mn,m}pm extensions as part of Zjpm v1.0

Posted by Richard Henderson 1 week, 5 days ago

On 11/7/24 22:01, baturo.alexey@gmail.com wrote:
> @@ -2424,6 +2433,12 @@ static RISCVException write_senvcfg(CPURISCVState *env, int csrno,
>                                       target_ulong val)
>   {
>       uint64_t mask = SENVCFG_FIOM | SENVCFG_CBIE | SENVCFG_CBCFE | SENVCFG_CBZE;
> +    /* Update PMM field only if the value is valid according to Zjpm v1.0 */
> +    if (env_archcpu(env)->cfg.ext_ssnpm &&
> +        riscv_cpu_mxl(env) == MXL_RV64 &&
> +        (get_field(val, SENVCFG_PMM) != PMM_FIELD_RESERVED)) {
> +        mask |= SENVCFG_PMM;
> +    }
>       RISCVException ret;
>   
>       ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);

Do not insert statements into the declarations at the start of the block.
Drop the unnecessary () around != (multiple instances).

> @@ -3525,6 +3546,15 @@ static RISCVException read_hstatus(CPURISCVState *env, int csrno,
>   static RISCVException write_hstatus(CPURISCVState *env, int csrno,
>                                       target_ulong val)
>   {
> +    uint64_t mask = (target_ulong)-1;
> +    /* Update PMM field only if the value is valid according to Zjpm v1.0 */
> +    if (env_archcpu(env)->cfg.ext_ssnpm &&
> +        (riscv_cpu_mxl(env) == MXL_RV64) &&
> +        (get_field(val, HSTATUS_HUPMM) == PMM_FIELD_RESERVED)) {
> +        mask &= ~HSTATUS_HUPMM;
> +    }

Surely you'd not install HUPMM if ext_ssnpm is false?
Is this missing other extension checks?


> +    env->hstatus = (env->hstatus & ~mask) | (val & mask);
> +
>       env->hstatus = val;

Failure to remove previous assignment.


r~

[PATCH 1/7] target/riscv: Remove obsolete pointer masking extension code.
[PATCH 2/7] target/riscv: Add new CSR fields for S{sn, mn, m}pm extensions as part of Zjpm v1.0
[PATCH 3/7] target/riscv: Add helper functions to calculate current number of masked bits for pointer masking
[PATCH 4/7] target/riscv: Add pointer masking tb flags
[PATCH 5/7] target/riscv: Update address modify functions to take into account pointer masking
[PATCH 6/7] target/riscv: Apply pointer masking for virtualized memory accesses
[PATCH 7/7] target/riscv: Enable updates for pointer masking variables and thus enable pointer masking extension