[PATCH for-8.1 v3 00/26] target/riscv: rework CPU extensions validation

[PATCH for-8.1 v3 00/26] target/riscv: rework CPU extensions validation

[Daniel Henrique Barboza]

Hi,

This new version contains changes suggested by Weiwei Li. I've also
reworked write_misa() to cover more cases. write_misa() is now able to
properly enable RVG, RVV and RVE.

A more in-depth description of what was attempted here can be found in
[1]. Note that the current validation flow already prevents certain misa
bits from being disabled (e.g. RVF) due to the presence of Z extensions
that are already enabled in the hart, so I decided not to add extra
logic to handle these cases.

Patches are rebased on top of Alistair's riscv-to-apply.next.

Changes from v2:
- patches removed:
  - patch 15 ('do not allow RVG in write_misa()')
  - patch 19 ('add misa_ext V-> D & F dependency')
- patch 15:
  - add zfinx dependency to enable RVG
- patch 19 (former patch 17):
  -  remove misa_ext* assignment from validate_set_extensions()
- patch 23 (former 25):
  - enable RVE in write_misa()
- new patch 25:
  - enable RVG in write_misa()
- new patch 26:
  - enable RVV in write_misa()
- v2 link: https://lists.gnu.org/archive/html/qemu-devel/2023-03/msg04424.html

[1] https://lists.gnu.org/archive/html/qemu-devel/2023-03/msg04674.html

Daniel Henrique Barboza (26):
  target/riscv/cpu.c: add riscv_cpu_validate_v()
  target/riscv/cpu.c: remove set_vext_version()
  target/riscv/cpu.c: remove set_priv_version()
  target/riscv: add PRIV_VERSION_LATEST
  target/riscv/cpu.c: add priv_spec validate/disable_exts helpers
  target/riscv/cpu.c: add riscv_cpu_validate_misa_mxl()
  target/riscv: move pmp and epmp validations to
    validate_set_extensions()
  target/riscv/cpu.c: validate extensions before riscv_timer_init()
  target/riscv/cpu.c: remove cfg setup from riscv_cpu_init()
  target/riscv/cpu.c: avoid set_misa() in validate_set_extensions()
  target/riscv/cpu.c: set cpu config in set_misa()
  target/riscv/cpu.c: redesign register_cpu_props()
  target/riscv: put env->misa_ext <-> cpu->cfg code into helpers
  target/riscv: add RVG
  target/riscv/cpu.c: split RVG code from validate_set_extensions()
  target/riscv/cpu.c: add riscv_cpu_validate_misa_ext()
  target/riscv: move riscv_cpu_validate_v() to validate_misa_ext()
  target/riscv: error out on priv failure for RVH
  target/riscv: write env->misa_ext* in register_generic_cpu_props()
  target/riscv: make validate_misa_ext() use a misa_ext val
  target/riscv: split riscv_cpu_validate_set_extensions()
  target/riscv: use misa_ext val in riscv_cpu_validate_extensions()
  target/riscv: rework write_misa()
  target/riscv: update cpu->cfg misa bits in commit_cpu_cfg()
  target/riscv: allow write_misa() to enable RVG
  target/riscv: allow write_misa() to enable RVV

 target/riscv/cpu.c | 691 +++++++++++++++++++++++++++++----------------
 target/riscv/cpu.h |  17 +-
 target/riscv/csr.c |  85 ++++--
 3 files changed, 522 insertions(+), 271 deletions(-)

-- 
2.39.2

[PATCH for-8.1 v3 01/26] target/riscv/cpu.c: add riscv_cpu_validate_v()

[Daniel Henrique Barboza]

The RVV verification will error out if fails and it's being done at the
end of riscv_cpu_validate_set_extensions(). Let's put it in its own
function and do it earlier.

We'll move it out of riscv_cpu_validate_set_extensions() in the near future,
but for now this is enough to clean the code a bit.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 86 ++++++++++++++++++++++++++--------------------
 1 file changed, 49 insertions(+), 37 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 1e97473af2..18591aa53a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -802,6 +802,46 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
     }
 }
 
+static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
+                                 Error **errp)
+{
+    int vext_version = VEXT_VERSION_1_00_0;
+
+    if (!is_power_of_2(cfg->vlen)) {
+        error_setg(errp, "Vector extension VLEN must be power of 2");
+        return;
+    }
+    if (cfg->vlen > RV_VLEN_MAX || cfg->vlen < 128) {
+        error_setg(errp,
+                   "Vector extension implementation only supports VLEN "
+                   "in the range [128, %d]", RV_VLEN_MAX);
+        return;
+    }
+    if (!is_power_of_2(cfg->elen)) {
+        error_setg(errp, "Vector extension ELEN must be power of 2");
+        return;
+    }
+    if (cfg->elen > 64 || cfg->elen < 8) {
+        error_setg(errp,
+                   "Vector extension implementation only supports ELEN "
+                   "in the range [8, 64]");
+        return;
+    }
+    if (cfg->vext_spec) {
+        if (!g_strcmp0(cfg->vext_spec, "v1.0")) {
+            vext_version = VEXT_VERSION_1_00_0;
+        } else {
+            error_setg(errp, "Unsupported vector spec version '%s'",
+                       cfg->vext_spec);
+            return;
+        }
+    } else {
+        qemu_log("vector version is not specified, "
+                 "use the default value v1.0\n");
+    }
+    set_vext_version(env, vext_version);
+}
+
 /*
  * Check consistency between chosen extensions while setting
  * cpu->cfg accordingly, doing a set_misa() in the end.
@@ -809,6 +849,7 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
 static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
 {
     CPURISCVState *env = &cpu->env;
+    Error *local_err = NULL;
     uint32_t ext = 0;
 
     /* Do some ISA extension error checking */
@@ -939,6 +980,14 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         }
     }
 
+    if (cpu->cfg.ext_v) {
+        riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
+        if (local_err != NULL) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
+
     if (cpu->cfg.ext_zk) {
         cpu->cfg.ext_zkn = true;
         cpu->cfg.ext_zkr = true;
@@ -993,44 +1042,7 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         ext |= RVH;
     }
     if (cpu->cfg.ext_v) {
-        int vext_version = VEXT_VERSION_1_00_0;
         ext |= RVV;
-        if (!is_power_of_2(cpu->cfg.vlen)) {
-            error_setg(errp,
-                       "Vector extension VLEN must be power of 2");
-            return;
-        }
-        if (cpu->cfg.vlen > RV_VLEN_MAX || cpu->cfg.vlen < 128) {
-            error_setg(errp,
-                       "Vector extension implementation only supports VLEN "
-                       "in the range [128, %d]", RV_VLEN_MAX);
-            return;
-        }
-        if (!is_power_of_2(cpu->cfg.elen)) {
-            error_setg(errp,
-                       "Vector extension ELEN must be power of 2");
-            return;
-        }
-        if (cpu->cfg.elen > 64 || cpu->cfg.elen < 8) {
-            error_setg(errp,
-                       "Vector extension implementation only supports ELEN "
-                       "in the range [8, 64]");
-            return;
-        }
-        if (cpu->cfg.vext_spec) {
-            if (!g_strcmp0(cpu->cfg.vext_spec, "v1.0")) {
-                vext_version = VEXT_VERSION_1_00_0;
-            } else {
-                error_setg(errp,
-                           "Unsupported vector spec version '%s'",
-                           cpu->cfg.vext_spec);
-                return;
-            }
-        } else {
-            qemu_log("vector version is not specified, "
-                     "use the default value v1.0\n");
-        }
-        set_vext_version(env, vext_version);
     }
     if (cpu->cfg.ext_j) {
         ext |= RVJ;
-- 
2.39.2

Re: [PATCH for-8.1 v3 01/26] target/riscv/cpu.c: add riscv_cpu_validate_v()

[LIU Zhiwei]

On 2023/3/19 4:04, Daniel Henrique Barboza wrote:
> The RVV verification will error out if fails and it's being done at the
> end of riscv_cpu_validate_set_extensions(). Let's put it in its own
> function and do it earlier.
>
> We'll move it out of riscv_cpu_validate_set_extensions() in the near future,
> but for now this is enough to clean the code a bit.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 86 ++++++++++++++++++++++++++--------------------
>   1 file changed, 49 insertions(+), 37 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 1e97473af2..18591aa53a 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -802,6 +802,46 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
>       }
>   }
>   
> +static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
> +                                 Error **errp)
> +{
> +    int vext_version = VEXT_VERSION_1_00_0;
> +
> +    if (!is_power_of_2(cfg->vlen)) {
> +        error_setg(errp, "Vector extension VLEN must be power of 2");
> +        return;
> +    }
> +    if (cfg->vlen > RV_VLEN_MAX || cfg->vlen < 128) {
> +        error_setg(errp,
> +                   "Vector extension implementation only supports VLEN "
> +                   "in the range [128, %d]", RV_VLEN_MAX);
> +        return;
> +    }
> +    if (!is_power_of_2(cfg->elen)) {
> +        error_setg(errp, "Vector extension ELEN must be power of 2");
> +        return;
> +    }
> +    if (cfg->elen > 64 || cfg->elen < 8) {
> +        error_setg(errp,
> +                   "Vector extension implementation only supports ELEN "
> +                   "in the range [8, 64]");
> +        return;
> +    }
> +    if (cfg->vext_spec) {
> +        if (!g_strcmp0(cfg->vext_spec, "v1.0")) {
> +            vext_version = VEXT_VERSION_1_00_0;
> +        } else {
> +            error_setg(errp, "Unsupported vector spec version '%s'",
> +                       cfg->vext_spec);
> +            return;
> +        }
> +    } else {
> +        qemu_log("vector version is not specified, "
> +                 "use the default value v1.0\n");
> +    }
> +    set_vext_version(env, vext_version);
> +}
> +
>   /*
>    * Check consistency between chosen extensions while setting
>    * cpu->cfg accordingly, doing a set_misa() in the end.
> @@ -809,6 +849,7 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
>   static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>   {
>       CPURISCVState *env = &cpu->env;
> +    Error *local_err = NULL;
>       uint32_t ext = 0;
>   
>       /* Do some ISA extension error checking */
> @@ -939,6 +980,14 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>           }
>       }
>   
> +    if (cpu->cfg.ext_v) {
> +        riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
> +        if (local_err != NULL) {
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +    }
> +
>       if (cpu->cfg.ext_zk) {
>           cpu->cfg.ext_zkn = true;
>           cpu->cfg.ext_zkr = true;
> @@ -993,44 +1042,7 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>           ext |= RVH;
>       }
>       if (cpu->cfg.ext_v) {
> -        int vext_version = VEXT_VERSION_1_00_0;
>           ext |= RVV;
> -        if (!is_power_of_2(cpu->cfg.vlen)) {
> -            error_setg(errp,
> -                       "Vector extension VLEN must be power of 2");
> -            return;
> -        }
> -        if (cpu->cfg.vlen > RV_VLEN_MAX || cpu->cfg.vlen < 128) {
> -            error_setg(errp,
> -                       "Vector extension implementation only supports VLEN "
> -                       "in the range [128, %d]", RV_VLEN_MAX);
> -            return;
> -        }
> -        if (!is_power_of_2(cpu->cfg.elen)) {
> -            error_setg(errp,
> -                       "Vector extension ELEN must be power of 2");
> -            return;
> -        }
> -        if (cpu->cfg.elen > 64 || cpu->cfg.elen < 8) {
> -            error_setg(errp,
> -                       "Vector extension implementation only supports ELEN "
> -                       "in the range [8, 64]");
> -            return;
> -        }
> -        if (cpu->cfg.vext_spec) {
> -            if (!g_strcmp0(cpu->cfg.vext_spec, "v1.0")) {
> -                vext_version = VEXT_VERSION_1_00_0;
> -            } else {
> -                error_setg(errp,
> -                           "Unsupported vector spec version '%s'",
> -                           cpu->cfg.vext_spec);
> -                return;
> -            }
> -        } else {
> -            qemu_log("vector version is not specified, "
> -                     "use the default value v1.0\n");
> -        }
> -        set_vext_version(env, vext_version);

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

>       }
>       if (cpu->cfg.ext_j) {
>           ext |= RVJ;

[PATCH for-8.1 v3 02/26] target/riscv/cpu.c: remove set_vext_version()

[Daniel Henrique Barboza]

This setter is doing nothing else but setting env->vext_ver. Assign the
value directly.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 18591aa53a..2752efe1eb 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -245,11 +245,6 @@ static void set_priv_version(CPURISCVState *env, int priv_ver)
     env->priv_ver = priv_ver;
 }
 
-static void set_vext_version(CPURISCVState *env, int vext_ver)
-{
-    env->vext_ver = vext_ver;
-}
-
 #ifndef CONFIG_USER_ONLY
 static uint8_t satp_mode_from_str(const char *satp_mode_str)
 {
@@ -839,7 +834,7 @@ static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
         qemu_log("vector version is not specified, "
                  "use the default value v1.0\n");
     }
-    set_vext_version(env, vext_version);
+    env->vext_ver = vext_version;
 }
 
 /*
-- 
2.39.2

Re: [PATCH for-8.1 v3 02/26] target/riscv/cpu.c: remove set_vext_version()

[LIU Zhiwei]

On 2023/3/19 4:04, Daniel Henrique Barboza wrote:
> This setter is doing nothing else but setting env->vext_ver. Assign the
> value directly.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 7 +------
>   1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 18591aa53a..2752efe1eb 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -245,11 +245,6 @@ static void set_priv_version(CPURISCVState *env, int priv_ver)
>       env->priv_ver = priv_ver;
>   }
>   
> -static void set_vext_version(CPURISCVState *env, int vext_ver)
> -{
> -    env->vext_ver = vext_ver;
> -}
> -
>   #ifndef CONFIG_USER_ONLY
>   static uint8_t satp_mode_from_str(const char *satp_mode_str)
>   {
> @@ -839,7 +834,7 @@ static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
>           qemu_log("vector version is not specified, "
>                    "use the default value v1.0\n");
>       }
> -    set_vext_version(env, vext_version);
> +    env->vext_ver = vext_version;
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei
>   }
>   
>   /*

[PATCH for-8.1 v3 03/26] target/riscv/cpu.c: remove set_priv_version()

[Daniel Henrique Barboza]

The setter is doing nothing special. Just set env->priv_ver directly.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 2752efe1eb..18032dfd4e 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -240,11 +240,6 @@ static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
     env->misa_ext_mask = env->misa_ext = ext;
 }
 
-static void set_priv_version(CPURISCVState *env, int priv_ver)
-{
-    env->priv_ver = priv_ver;
-}
-
 #ifndef CONFIG_USER_ONLY
 static uint8_t satp_mode_from_str(const char *satp_mode_str)
 {
@@ -343,7 +338,7 @@ static void riscv_any_cpu_init(Object *obj)
                                     VM_1_10_SV32 : VM_1_10_SV57);
 #endif
 
-    set_priv_version(env, PRIV_VERSION_1_12_0);
+    env->priv_ver = PRIV_VERSION_1_12_0;
     register_cpu_props(obj);
 }
 
@@ -355,7 +350,7 @@ static void rv64_base_cpu_init(Object *obj)
     set_misa(env, MXL_RV64, 0);
     register_cpu_props(obj);
     /* Set latest version of privileged specification */
-    set_priv_version(env, PRIV_VERSION_1_12_0);
+    env->priv_ver = PRIV_VERSION_1_12_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
 #endif
@@ -366,7 +361,7 @@ static void rv64_sifive_u_cpu_init(Object *obj)
     CPURISCVState *env = &RISCV_CPU(obj)->env;
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
     register_cpu_props(obj);
-    set_priv_version(env, PRIV_VERSION_1_10_0);
+    env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV39);
 #endif
@@ -379,7 +374,7 @@ static void rv64_sifive_e_cpu_init(Object *obj)
 
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVC | RVU);
     register_cpu_props(obj);
-    set_priv_version(env, PRIV_VERSION_1_10_0);
+    env->priv_ver = PRIV_VERSION_1_10_0;
     cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -392,7 +387,7 @@ static void rv64_thead_c906_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
 
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
-    set_priv_version(env, PRIV_VERSION_1_11_0);
+    env->priv_ver = PRIV_VERSION_1_11_0;
 
     cpu->cfg.ext_g = true;
     cpu->cfg.ext_c = true;
@@ -431,7 +426,7 @@ static void rv128_base_cpu_init(Object *obj)
     set_misa(env, MXL_RV128, 0);
     register_cpu_props(obj);
     /* Set latest version of privileged specification */
-    set_priv_version(env, PRIV_VERSION_1_12_0);
+    env->priv_ver = PRIV_VERSION_1_12_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
 #endif
@@ -444,7 +439,7 @@ static void rv32_base_cpu_init(Object *obj)
     set_misa(env, MXL_RV32, 0);
     register_cpu_props(obj);
     /* Set latest version of privileged specification */
-    set_priv_version(env, PRIV_VERSION_1_12_0);
+    env->priv_ver = PRIV_VERSION_1_12_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
 #endif
@@ -454,8 +449,9 @@ static void rv32_sifive_u_cpu_init(Object *obj)
 {
     CPURISCVState *env = &RISCV_CPU(obj)->env;
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
+
     register_cpu_props(obj);
-    set_priv_version(env, PRIV_VERSION_1_10_0);
+    env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
 #endif
@@ -468,7 +464,7 @@ static void rv32_sifive_e_cpu_init(Object *obj)
 
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVC | RVU);
     register_cpu_props(obj);
-    set_priv_version(env, PRIV_VERSION_1_10_0);
+    env->priv_ver = PRIV_VERSION_1_10_0;
     cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -482,7 +478,7 @@ static void rv32_ibex_cpu_init(Object *obj)
 
     set_misa(env, MXL_RV32, RVI | RVM | RVC | RVU);
     register_cpu_props(obj);
-    set_priv_version(env, PRIV_VERSION_1_11_0);
+    env->priv_ver = PRIV_VERSION_1_11_0;
     cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -497,7 +493,7 @@ static void rv32_imafcu_nommu_cpu_init(Object *obj)
 
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVC | RVU);
     register_cpu_props(obj);
-    set_priv_version(env, PRIV_VERSION_1_10_0);
+    env->priv_ver = PRIV_VERSION_1_10_0;
     cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -1160,7 +1156,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     }
 
     if (priv_version >= PRIV_VERSION_1_10_0) {
-        set_priv_version(env, priv_version);
+        env->priv_ver = priv_version;
     }
 
     /* Force disable extensions if priv spec version does not match */
-- 
2.39.2

Re: [PATCH for-8.1 v3 03/26] target/riscv/cpu.c: remove set_priv_version()

[LIU Zhiwei]

On 2023/3/19 4:04, Daniel Henrique Barboza wrote:
> The setter is doing nothing special. Just set env->priv_ver directly.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 30 +++++++++++++-----------------
>   1 file changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 2752efe1eb..18032dfd4e 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -240,11 +240,6 @@ static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
>       env->misa_ext_mask = env->misa_ext = ext;
>   }
>   
> -static void set_priv_version(CPURISCVState *env, int priv_ver)
> -{
> -    env->priv_ver = priv_ver;
> -}
> -
>   #ifndef CONFIG_USER_ONLY
>   static uint8_t satp_mode_from_str(const char *satp_mode_str)
>   {
> @@ -343,7 +338,7 @@ static void riscv_any_cpu_init(Object *obj)
>                                       VM_1_10_SV32 : VM_1_10_SV57);
>   #endif
>   
> -    set_priv_version(env, PRIV_VERSION_1_12_0);
> +    env->priv_ver = PRIV_VERSION_1_12_0;
>       register_cpu_props(obj);
>   }
>   
> @@ -355,7 +350,7 @@ static void rv64_base_cpu_init(Object *obj)
>       set_misa(env, MXL_RV64, 0);
>       register_cpu_props(obj);
>       /* Set latest version of privileged specification */
> -    set_priv_version(env, PRIV_VERSION_1_12_0);
> +    env->priv_ver = PRIV_VERSION_1_12_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
>   #endif
> @@ -366,7 +361,7 @@ static void rv64_sifive_u_cpu_init(Object *obj)
>       CPURISCVState *env = &RISCV_CPU(obj)->env;
>       set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
>       register_cpu_props(obj);
> -    set_priv_version(env, PRIV_VERSION_1_10_0);
> +    env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV39);
>   #endif
> @@ -379,7 +374,7 @@ static void rv64_sifive_e_cpu_init(Object *obj)
>   
>       set_misa(env, MXL_RV64, RVI | RVM | RVA | RVC | RVU);
>       register_cpu_props(obj);
> -    set_priv_version(env, PRIV_VERSION_1_10_0);
> +    env->priv_ver = PRIV_VERSION_1_10_0;
>       cpu->cfg.mmu = false;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -392,7 +387,7 @@ static void rv64_thead_c906_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>   
>       set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
> -    set_priv_version(env, PRIV_VERSION_1_11_0);
> +    env->priv_ver = PRIV_VERSION_1_11_0;
>   
>       cpu->cfg.ext_g = true;
>       cpu->cfg.ext_c = true;
> @@ -431,7 +426,7 @@ static void rv128_base_cpu_init(Object *obj)
>       set_misa(env, MXL_RV128, 0);
>       register_cpu_props(obj);
>       /* Set latest version of privileged specification */
> -    set_priv_version(env, PRIV_VERSION_1_12_0);
> +    env->priv_ver = PRIV_VERSION_1_12_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
>   #endif
> @@ -444,7 +439,7 @@ static void rv32_base_cpu_init(Object *obj)
>       set_misa(env, MXL_RV32, 0);
>       register_cpu_props(obj);
>       /* Set latest version of privileged specification */
> -    set_priv_version(env, PRIV_VERSION_1_12_0);
> +    env->priv_ver = PRIV_VERSION_1_12_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
>   #endif
> @@ -454,8 +449,9 @@ static void rv32_sifive_u_cpu_init(Object *obj)
>   {
>       CPURISCVState *env = &RISCV_CPU(obj)->env;
>       set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
> +
>       register_cpu_props(obj);
> -    set_priv_version(env, PRIV_VERSION_1_10_0);
> +    env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
>   #endif
> @@ -468,7 +464,7 @@ static void rv32_sifive_e_cpu_init(Object *obj)
>   
>       set_misa(env, MXL_RV32, RVI | RVM | RVA | RVC | RVU);
>       register_cpu_props(obj);
> -    set_priv_version(env, PRIV_VERSION_1_10_0);
> +    env->priv_ver = PRIV_VERSION_1_10_0;
>       cpu->cfg.mmu = false;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -482,7 +478,7 @@ static void rv32_ibex_cpu_init(Object *obj)
>   
>       set_misa(env, MXL_RV32, RVI | RVM | RVC | RVU);
>       register_cpu_props(obj);
> -    set_priv_version(env, PRIV_VERSION_1_11_0);
> +    env->priv_ver = PRIV_VERSION_1_11_0;
>       cpu->cfg.mmu = false;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -497,7 +493,7 @@ static void rv32_imafcu_nommu_cpu_init(Object *obj)
>   
>       set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVC | RVU);
>       register_cpu_props(obj);
> -    set_priv_version(env, PRIV_VERSION_1_10_0);
> +    env->priv_ver = PRIV_VERSION_1_10_0;
>       cpu->cfg.mmu = false;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -1160,7 +1156,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
>       }
>   
>       if (priv_version >= PRIV_VERSION_1_10_0) {
> -        set_priv_version(env, priv_version);
> +        env->priv_ver = priv_version;
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei
>       }
>   
>       /* Force disable extensions if priv spec version does not match */

[PATCH for-8.1 v3 04/26] target/riscv: add PRIV_VERSION_LATEST

[Daniel Henrique Barboza]

All these generic CPUs are using the latest priv available, at this
moment PRIV_VERSION_1_12_0:

- riscv_any_cpu_init()
- rv32_base_cpu_init()
- rv64_base_cpu_init()
- rv128_base_cpu_init()

Create a new PRIV_VERSION_LATEST enum and use it in those cases. I'll
make it easier to update everything at once when a new priv version is
available.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 8 ++++----
 target/riscv/cpu.h | 2 ++
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 18032dfd4e..1ee322001b 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -338,7 +338,7 @@ static void riscv_any_cpu_init(Object *obj)
                                     VM_1_10_SV32 : VM_1_10_SV57);
 #endif
 
-    env->priv_ver = PRIV_VERSION_1_12_0;
+    env->priv_ver = PRIV_VERSION_LATEST;
     register_cpu_props(obj);
 }
 
@@ -350,7 +350,7 @@ static void rv64_base_cpu_init(Object *obj)
     set_misa(env, MXL_RV64, 0);
     register_cpu_props(obj);
     /* Set latest version of privileged specification */
-    env->priv_ver = PRIV_VERSION_1_12_0;
+    env->priv_ver = PRIV_VERSION_LATEST;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
 #endif
@@ -426,7 +426,7 @@ static void rv128_base_cpu_init(Object *obj)
     set_misa(env, MXL_RV128, 0);
     register_cpu_props(obj);
     /* Set latest version of privileged specification */
-    env->priv_ver = PRIV_VERSION_1_12_0;
+    env->priv_ver = PRIV_VERSION_LATEST;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
 #endif
@@ -439,7 +439,7 @@ static void rv32_base_cpu_init(Object *obj)
     set_misa(env, MXL_RV32, 0);
     register_cpu_props(obj);
     /* Set latest version of privileged specification */
-    env->priv_ver = PRIV_VERSION_1_12_0;
+    env->priv_ver = PRIV_VERSION_LATEST;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
 #endif
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 638e47c75a..76f81c6b68 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -88,6 +88,8 @@ enum {
     PRIV_VERSION_1_10_0 = 0,
     PRIV_VERSION_1_11_0,
     PRIV_VERSION_1_12_0,
+
+    PRIV_VERSION_LATEST = PRIV_VERSION_1_12_0,
 };
 
 #define VEXT_VERSION_1_00_0 0x00010000
-- 
2.39.2

Re: [PATCH for-8.1 v3 04/26] target/riscv: add PRIV_VERSION_LATEST

[LIU Zhiwei]

On 2023/3/19 4:04, Daniel Henrique Barboza wrote:
> All these generic CPUs are using the latest priv available, at this
> moment PRIV_VERSION_1_12_0:
>
> - riscv_any_cpu_init()
> - rv32_base_cpu_init()
> - rv64_base_cpu_init()
> - rv128_base_cpu_init()
>
> Create a new PRIV_VERSION_LATEST enum and use it in those cases. I'll
> make it easier to update everything at once when a new priv version is
> available.
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 8 ++++----
>   target/riscv/cpu.h | 2 ++
>   2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 18032dfd4e..1ee322001b 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -338,7 +338,7 @@ static void riscv_any_cpu_init(Object *obj)
>                                       VM_1_10_SV32 : VM_1_10_SV57);
>   #endif
>   
> -    env->priv_ver = PRIV_VERSION_1_12_0;
> +    env->priv_ver = PRIV_VERSION_LATEST;
>       register_cpu_props(obj);
>   }
>   
> @@ -350,7 +350,7 @@ static void rv64_base_cpu_init(Object *obj)
>       set_misa(env, MXL_RV64, 0);
>       register_cpu_props(obj);
>       /* Set latest version of privileged specification */
> -    env->priv_ver = PRIV_VERSION_1_12_0;
> +    env->priv_ver = PRIV_VERSION_LATEST;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
>   #endif
> @@ -426,7 +426,7 @@ static void rv128_base_cpu_init(Object *obj)
>       set_misa(env, MXL_RV128, 0);
>       register_cpu_props(obj);
>       /* Set latest version of privileged specification */
> -    env->priv_ver = PRIV_VERSION_1_12_0;
> +    env->priv_ver = PRIV_VERSION_LATEST;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV57);
>   #endif
> @@ -439,7 +439,7 @@ static void rv32_base_cpu_init(Object *obj)
>       set_misa(env, MXL_RV32, 0);
>       register_cpu_props(obj);
>       /* Set latest version of privileged specification */
> -    env->priv_ver = PRIV_VERSION_1_12_0;
> +    env->priv_ver = PRIV_VERSION_LATEST;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
>   #endif
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 638e47c75a..76f81c6b68 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -88,6 +88,8 @@ enum {
>       PRIV_VERSION_1_10_0 = 0,
>       PRIV_VERSION_1_11_0,
>       PRIV_VERSION_1_12_0,
> +
> +    PRIV_VERSION_LATEST = PRIV_VERSION_1_12_0,
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei
>   };
>   
>   #define VEXT_VERSION_1_00_0 0x00010000

[PATCH for-8.1 v3 05/26] target/riscv/cpu.c: add priv_spec validate/disable_exts helpers

[Daniel Henrique Barboza]

We're doing env->priv_spec validation and assignment at the start of
riscv_cpu_realize(), which is fine, but then we're doing a force disable
on extensions that aren't compatible with the priv version.

This second step is being done too early. The disabled extensions might be
re-enabled again in riscv_cpu_validate_set_extensions() by accident. A
better place to put this code is at the end of
riscv_cpu_validate_set_extensions() after all the validations are
completed.

Add a new helper, riscv_cpu_disable_priv_spec_isa_exts(), to disable the
extesions after the validation is done. While we're at it, create a
riscv_cpu_validate_priv_spec() helper to host all env->priv_spec related
validation to unclog riscv_cpu_realize a bit.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 91 ++++++++++++++++++++++++++++------------------
 1 file changed, 56 insertions(+), 35 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 1ee322001b..17b301967c 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -833,6 +833,52 @@ static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
     env->vext_ver = vext_version;
 }
 
+static void riscv_cpu_validate_priv_spec(RISCVCPU *cpu, Error **errp)
+{
+    CPURISCVState *env = &cpu->env;
+    int priv_version = -1;
+
+    if (cpu->cfg.priv_spec) {
+        if (!g_strcmp0(cpu->cfg.priv_spec, "v1.12.0")) {
+            priv_version = PRIV_VERSION_1_12_0;
+        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.11.0")) {
+            priv_version = PRIV_VERSION_1_11_0;
+        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.10.0")) {
+            priv_version = PRIV_VERSION_1_10_0;
+        } else {
+            error_setg(errp,
+                       "Unsupported privilege spec version '%s'",
+                       cpu->cfg.priv_spec);
+            return;
+        }
+
+        env->priv_ver = priv_version;
+    }
+}
+
+static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
+{
+    CPURISCVState *env = &cpu->env;
+    int i;
+
+    /* Force disable extensions if priv spec version does not match */
+    for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
+        if (isa_ext_is_enabled(cpu, &isa_edata_arr[i]) &&
+            (env->priv_ver < isa_edata_arr[i].min_version)) {
+            isa_ext_update_enabled(cpu, &isa_edata_arr[i], false);
+#ifndef CONFIG_USER_ONLY
+            warn_report("disabling %s extension for hart 0x" TARGET_FMT_lx
+                        " because privilege spec version does not match",
+                        isa_edata_arr[i].name, env->mhartid);
+#else
+            warn_report("disabling %s extension because "
+                        "privilege spec version does not match",
+                        isa_edata_arr[i].name);
+#endif
+        }
+    }
+}
+
 /*
  * Check consistency between chosen extensions while setting
  * cpu->cfg accordingly, doing a set_misa() in the end.
@@ -1002,6 +1048,12 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         cpu->cfg.ext_zksh = true;
     }
 
+    /*
+     * Disable isa extensions based on priv spec after we
+     * validated and set everything we need.
+     */
+    riscv_cpu_disable_priv_spec_isa_exts(cpu);
+
     if (cpu->cfg.ext_i) {
         ext |= RVI;
     }
@@ -1131,7 +1183,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     CPURISCVState *env = &cpu->env;
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
     CPUClass *cc = CPU_CLASS(mcc);
-    int i, priv_version = -1;
     Error *local_err = NULL;
 
     cpu_exec_realizefn(cs, &local_err);
@@ -1140,40 +1191,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (cpu->cfg.priv_spec) {
-        if (!g_strcmp0(cpu->cfg.priv_spec, "v1.12.0")) {
-            priv_version = PRIV_VERSION_1_12_0;
-        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.11.0")) {
-            priv_version = PRIV_VERSION_1_11_0;
-        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.10.0")) {
-            priv_version = PRIV_VERSION_1_10_0;
-        } else {
-            error_setg(errp,
-                       "Unsupported privilege spec version '%s'",
-                       cpu->cfg.priv_spec);
-            return;
-        }
-    }
-
-    if (priv_version >= PRIV_VERSION_1_10_0) {
-        env->priv_ver = priv_version;
-    }
-
-    /* Force disable extensions if priv spec version does not match */
-    for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
-        if (isa_ext_is_enabled(cpu, &isa_edata_arr[i]) &&
-            (env->priv_ver < isa_edata_arr[i].min_version)) {
-            isa_ext_update_enabled(cpu, &isa_edata_arr[i], false);
-#ifndef CONFIG_USER_ONLY
-            warn_report("disabling %s extension for hart 0x" TARGET_FMT_lx
-                        " because privilege spec version does not match",
-                        isa_edata_arr[i].name, env->mhartid);
-#else
-            warn_report("disabling %s extension because "
-                        "privilege spec version does not match",
-                        isa_edata_arr[i].name);
-#endif
-        }
+    riscv_cpu_validate_priv_spec(cpu, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return;
     }
 
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
-- 
2.39.2

Re: [PATCH for-8.1 v3 05/26] target/riscv/cpu.c: add priv_spec validate/disable_exts helpers

[LIU Zhiwei]

On 2023/3/19 4:04, Daniel Henrique Barboza wrote:
> We're doing env->priv_spec validation and assignment at the start of
> riscv_cpu_realize(), which is fine, but then we're doing a force disable
> on extensions that aren't compatible with the priv version.
>
> This second step is being done too early. The disabled extensions might be
> re-enabled again in riscv_cpu_validate_set_extensions() by accident.

It is not by accident. We should make sure if two extensions have 
dependency, their privilege
requirements should have the related dependency.  And we should write 
this dependency to the  isa_edata_arr.

I have sent the patch to the mail list to make this comment here clearer.

https://lists.gnu.org/archive/html/qemu-devel/2023-03/msg05361.html

Therefore it doesn't matter when do the priv_check or the 
validate_set_extension. Both work for me.

Based on that patch, this patch looks good to me.

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

>   A
> better place to put this code is at the end of
> riscv_cpu_validate_set_extensions() after all the validations are
> completed.
>
> Add a new helper, riscv_cpu_disable_priv_spec_isa_exts(), to disable the
> extesions after the validation is done. While we're at it, create a
> riscv_cpu_validate_priv_spec() helper to host all env->priv_spec related
> validation to unclog riscv_cpu_realize a bit.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 91 ++++++++++++++++++++++++++++------------------
>   1 file changed, 56 insertions(+), 35 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 1ee322001b..17b301967c 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -833,6 +833,52 @@ static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
>       env->vext_ver = vext_version;
>   }
>   
> +static void riscv_cpu_validate_priv_spec(RISCVCPU *cpu, Error **errp)
> +{
> +    CPURISCVState *env = &cpu->env;
> +    int priv_version = -1;
> +
> +    if (cpu->cfg.priv_spec) {
> +        if (!g_strcmp0(cpu->cfg.priv_spec, "v1.12.0")) {
> +            priv_version = PRIV_VERSION_1_12_0;
> +        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.11.0")) {
> +            priv_version = PRIV_VERSION_1_11_0;
> +        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.10.0")) {
> +            priv_version = PRIV_VERSION_1_10_0;
> +        } else {
> +            error_setg(errp,
> +                       "Unsupported privilege spec version '%s'",
> +                       cpu->cfg.priv_spec);
> +            return;
> +        }
> +
> +        env->priv_ver = priv_version;
> +    }
> +}
> +
> +static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
> +{
> +    CPURISCVState *env = &cpu->env;
> +    int i;
> +
> +    /* Force disable extensions if priv spec version does not match */
> +    for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
> +        if (isa_ext_is_enabled(cpu, &isa_edata_arr[i]) &&
> +            (env->priv_ver < isa_edata_arr[i].min_version)) {
> +            isa_ext_update_enabled(cpu, &isa_edata_arr[i], false);
> +#ifndef CONFIG_USER_ONLY
> +            warn_report("disabling %s extension for hart 0x" TARGET_FMT_lx
> +                        " because privilege spec version does not match",
> +                        isa_edata_arr[i].name, env->mhartid);
> +#else
> +            warn_report("disabling %s extension because "
> +                        "privilege spec version does not match",
> +                        isa_edata_arr[i].name);
> +#endif
> +        }
> +    }
> +}
> +
>   /*
>    * Check consistency between chosen extensions while setting
>    * cpu->cfg accordingly, doing a set_misa() in the end.
> @@ -1002,6 +1048,12 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>           cpu->cfg.ext_zksh = true;
>       }
>   
> +    /*
> +     * Disable isa extensions based on priv spec after we
> +     * validated and set everything we need.
> +     */
> +    riscv_cpu_disable_priv_spec_isa_exts(cpu);
> +
>       if (cpu->cfg.ext_i) {
>           ext |= RVI;
>       }
> @@ -1131,7 +1183,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
>       CPURISCVState *env = &cpu->env;
>       RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
>       CPUClass *cc = CPU_CLASS(mcc);
> -    int i, priv_version = -1;
>       Error *local_err = NULL;
>   
>       cpu_exec_realizefn(cs, &local_err);
> @@ -1140,40 +1191,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
>           return;
>       }
>   
> -    if (cpu->cfg.priv_spec) {
> -        if (!g_strcmp0(cpu->cfg.priv_spec, "v1.12.0")) {
> -            priv_version = PRIV_VERSION_1_12_0;
> -        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.11.0")) {
> -            priv_version = PRIV_VERSION_1_11_0;
> -        } else if (!g_strcmp0(cpu->cfg.priv_spec, "v1.10.0")) {
> -            priv_version = PRIV_VERSION_1_10_0;
> -        } else {
> -            error_setg(errp,
> -                       "Unsupported privilege spec version '%s'",
> -                       cpu->cfg.priv_spec);
> -            return;
> -        }
> -    }
> -
> -    if (priv_version >= PRIV_VERSION_1_10_0) {
> -        env->priv_ver = priv_version;
> -    }
> -
> -    /* Force disable extensions if priv spec version does not match */
> -    for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
> -        if (isa_ext_is_enabled(cpu, &isa_edata_arr[i]) &&
> -            (env->priv_ver < isa_edata_arr[i].min_version)) {
> -            isa_ext_update_enabled(cpu, &isa_edata_arr[i], false);
> -#ifndef CONFIG_USER_ONLY
> -            warn_report("disabling %s extension for hart 0x" TARGET_FMT_lx
> -                        " because privilege spec version does not match",
> -                        isa_edata_arr[i].name, env->mhartid);
> -#else
> -            warn_report("disabling %s extension because "
> -                        "privilege spec version does not match",
> -                        isa_edata_arr[i].name);
> -#endif
> -        }
> +    riscv_cpu_validate_priv_spec(cpu, &local_err);
> +    if (local_err != NULL) {
> +        error_propagate(errp, local_err);
> +        return;
>       }
>   
>       if (cpu->cfg.epmp && !cpu->cfg.pmp) {

[PATCH for-8.1 v3 06/26] target/riscv/cpu.c: add riscv_cpu_validate_misa_mxl()

[Daniel Henrique Barboza]

Let's remove more code that is open coded in riscv_cpu_realize() and put
it into a helper. Let's also add an error message instead of just
asserting out if env->misa_mxl_max != env->misa_mlx.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 51 ++++++++++++++++++++++++++++++----------------
 1 file changed, 33 insertions(+), 18 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 17b301967c..1a298e5e55 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -879,6 +879,33 @@ static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
     }
 }
 
+static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
+{
+    RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(cpu);
+    CPUClass *cc = CPU_CLASS(mcc);
+    CPURISCVState *env = &cpu->env;
+
+    /* Validate that MISA_MXL is set properly. */
+    switch (env->misa_mxl_max) {
+#ifdef TARGET_RISCV64
+    case MXL_RV64:
+    case MXL_RV128:
+        cc->gdb_core_xml_file = "riscv-64bit-cpu.xml";
+        break;
+#endif
+    case MXL_RV32:
+        cc->gdb_core_xml_file = "riscv-32bit-cpu.xml";
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    if (env->misa_mxl_max != env->misa_mxl) {
+        error_setg(errp, "misa_mxl_max must be equal to misa_mxl");
+        return;
+    }
+}
+
 /*
  * Check consistency between chosen extensions while setting
  * cpu->cfg accordingly, doing a set_misa() in the end.
@@ -1180,9 +1207,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
 {
     CPUState *cs = CPU(dev);
     RISCVCPU *cpu = RISCV_CPU(dev);
-    CPURISCVState *env = &cpu->env;
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
-    CPUClass *cc = CPU_CLASS(mcc);
     Error *local_err = NULL;
 
     cpu_exec_realizefn(cs, &local_err);
@@ -1197,6 +1222,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    riscv_cpu_validate_misa_mxl(cpu, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
         /*
          * Enhanced PMP should only be available
@@ -1213,22 +1244,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     }
 #endif /* CONFIG_USER_ONLY */
 
-    /* Validate that MISA_MXL is set properly. */
-    switch (env->misa_mxl_max) {
-#ifdef TARGET_RISCV64
-    case MXL_RV64:
-    case MXL_RV128:
-        cc->gdb_core_xml_file = "riscv-64bit-cpu.xml";
-        break;
-#endif
-    case MXL_RV32:
-        cc->gdb_core_xml_file = "riscv-32bit-cpu.xml";
-        break;
-    default:
-        g_assert_not_reached();
-    }
-    assert(env->misa_mxl_max == env->misa_mxl);
-
     riscv_cpu_validate_set_extensions(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-- 
2.39.2

[PATCH for-8.1 v3 07/26] target/riscv: move pmp and epmp validations to validate_set_extensions()

[Daniel Henrique Barboza]

In the near future, write_misa() will use a variation of what we have
now as riscv_cpu_validate_set_extensions(). The pmp and epmp validation
will be required in write_misa() and it's already required here in
riscv_cpu_realize(), so move it to riscv_cpu_validate_set_extensions().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 1a298e5e55..7458845fec 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -916,6 +916,15 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
     Error *local_err = NULL;
     uint32_t ext = 0;
 
+    if (cpu->cfg.epmp && !cpu->cfg.pmp) {
+        /*
+         * Enhanced PMP should only be available
+         * on harts with PMP support
+         */
+        error_setg(errp, "Invalid configuration: EPMP requires PMP support");
+        return;
+    }
+
     /* Do some ISA extension error checking */
     if (cpu->cfg.ext_g && !(cpu->cfg.ext_i && cpu->cfg.ext_m &&
                             cpu->cfg.ext_a && cpu->cfg.ext_f &&
@@ -1228,16 +1237,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (cpu->cfg.epmp && !cpu->cfg.pmp) {
-        /*
-         * Enhanced PMP should only be available
-         * on harts with PMP support
-         */
-        error_setg(errp, "Invalid configuration: EPMP requires PMP support");
-        return;
-    }
-
-
 #ifndef CONFIG_USER_ONLY
     if (cpu->cfg.ext_sstc) {
         riscv_timer_init(cpu);
-- 
2.39.2

[PATCH for-8.1 v3 08/26] target/riscv/cpu.c: validate extensions before riscv_timer_init()

[Daniel Henrique Barboza]

There is no need to init timers if we're not even sure that our
extensions are valid. Execute riscv_cpu_validate_set_extensions() before
riscv_timer_init().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 7458845fec..fef55d7d79 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1237,12 +1237,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-#ifndef CONFIG_USER_ONLY
-    if (cpu->cfg.ext_sstc) {
-        riscv_timer_init(cpu);
-    }
-#endif /* CONFIG_USER_ONLY */
-
     riscv_cpu_validate_set_extensions(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
@@ -1250,6 +1244,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     }
 
 #ifndef CONFIG_USER_ONLY
+    if (cpu->cfg.ext_sstc) {
+        riscv_timer_init(cpu);
+    }
+
     if (cpu->cfg.pmu_num) {
         if (!riscv_pmu_init(cpu, cpu->cfg.pmu_num) && cpu->cfg.ext_sscofpmf) {
             cpu->pmu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
-- 
2.39.2

[PATCH for-8.1 v3 09/26] target/riscv/cpu.c: remove cfg setup from riscv_cpu_init()

[Daniel Henrique Barboza]

We have 4 config settings being done in riscv_cpu_init(): ext_ifencei,
ext_icsr, mmu and pmp. This is also the constructor of the "riscv-cpu"
device, which happens to be the parent device of every RISC-V cpu.

The result is that these 4 configs are being set every time, and every
other CPU should always account for them. CPUs such as sifive_e need to
disable settings that aren't enabled simply because the parent class
happens to be enabling it.

Moving all configurations from the parent class to each CPU will
centralize the config of each CPU into its own init(), which is clearer
than having to account to whatever happens to be set in the parent
device. These settings are also being set in register_cpu_props() when
no 'misa_ext' is set, so for these CPUs we don't need changes. Named
CPUs will receive all cfgs that the parent were setting into their
init().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 60 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 48 insertions(+), 12 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index fef55d7d79..c7b6e7b84b 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -325,7 +325,8 @@ static void set_satp_mode_default_map(RISCVCPU *cpu)
 
 static void riscv_any_cpu_init(Object *obj)
 {
-    CPURISCVState *env = &RISCV_CPU(obj)->env;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    CPURISCVState *env = &cpu->env;
 #if defined(TARGET_RISCV32)
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVU);
 #elif defined(TARGET_RISCV64)
@@ -340,6 +341,12 @@ static void riscv_any_cpu_init(Object *obj)
 
     env->priv_ver = PRIV_VERSION_LATEST;
     register_cpu_props(obj);
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.mmu = true;
+    cpu->cfg.pmp = true;
 }
 
 #if defined(TARGET_RISCV64)
@@ -358,13 +365,20 @@ static void rv64_base_cpu_init(Object *obj)
 
 static void rv64_sifive_u_cpu_init(Object *obj)
 {
-    CPURISCVState *env = &RISCV_CPU(obj)->env;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    CPURISCVState *env = &cpu->env;
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
     register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV39);
 #endif
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.mmu = true;
+    cpu->cfg.pmp = true;
 }
 
 static void rv64_sifive_e_cpu_init(Object *obj)
@@ -375,10 +389,14 @@ static void rv64_sifive_e_cpu_init(Object *obj)
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVC | RVU);
     register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
-    cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
 #endif
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.pmp = true;
 }
 
 static void rv64_thead_c906_cpu_init(Object *obj)
@@ -411,6 +429,10 @@ static void rv64_thead_c906_cpu_init(Object *obj)
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_SV39);
 #endif
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.pmp = true;
 }
 
 static void rv128_base_cpu_init(Object *obj)
@@ -447,7 +469,8 @@ static void rv32_base_cpu_init(Object *obj)
 
 static void rv32_sifive_u_cpu_init(Object *obj)
 {
-    CPURISCVState *env = &RISCV_CPU(obj)->env;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    CPURISCVState *env = &cpu->env;
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
 
     register_cpu_props(obj);
@@ -455,6 +478,12 @@ static void rv32_sifive_u_cpu_init(Object *obj)
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
 #endif
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.mmu = true;
+    cpu->cfg.pmp = true;
 }
 
 static void rv32_sifive_e_cpu_init(Object *obj)
@@ -465,10 +494,14 @@ static void rv32_sifive_e_cpu_init(Object *obj)
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVC | RVU);
     register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
-    cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
 #endif
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.pmp = true;
 }
 
 static void rv32_ibex_cpu_init(Object *obj)
@@ -479,11 +512,15 @@ static void rv32_ibex_cpu_init(Object *obj)
     set_misa(env, MXL_RV32, RVI | RVM | RVC | RVU);
     register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_11_0;
-    cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
 #endif
     cpu->cfg.epmp = true;
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.pmp = true;
 }
 
 static void rv32_imafcu_nommu_cpu_init(Object *obj)
@@ -494,10 +531,14 @@ static void rv32_imafcu_nommu_cpu_init(Object *obj)
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVC | RVU);
     register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
-    cpu->cfg.mmu = false;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
 #endif
+
+    /* inherited from parent obj via riscv_cpu_init() */
+    cpu->cfg.ext_ifencei = true;
+    cpu->cfg.ext_icsr = true;
+    cpu->cfg.pmp = true;
 }
 #endif
 
@@ -1384,11 +1425,6 @@ static void riscv_cpu_init(Object *obj)
 {
     RISCVCPU *cpu = RISCV_CPU(obj);
 
-    cpu->cfg.ext_ifencei = true;
-    cpu->cfg.ext_icsr = true;
-    cpu->cfg.mmu = true;
-    cpu->cfg.pmp = true;
-
     cpu_set_cpustate_pointers(cpu);
 
 #ifndef CONFIG_USER_ONLY
-- 
2.39.2

[PATCH for-8.1 v3 10/26] target/riscv/cpu.c: avoid set_misa() in validate_set_extensions()

[Daniel Henrique Barboza]

set_misa() will be tuned up to do more than it's already doing and it
will be redundant to what riscv_cpu_validate_set_extensions() does.

Note that we don't ever change env->misa_mlx in this function, so
set_misa() can be replaced by just assigning env->misa_ext and
env->misa_ext_mask to 'ext'.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index c7b6e7b84b..36c55abda0 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -949,7 +949,8 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
 
 /*
  * Check consistency between chosen extensions while setting
- * cpu->cfg accordingly, doing a set_misa() in the end.
+ * cpu->cfg accordingly, setting env->misa_ext and
+ * misa_ext_mask in the end.
  */
 static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
 {
@@ -1168,7 +1169,7 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         ext |= RVJ;
     }
 
-    set_misa(env, env->misa_mxl, ext);
+    env->misa_ext_mask = env->misa_ext = ext;
 }
 
 #ifndef CONFIG_USER_ONLY
-- 
2.39.2

[PATCH for-8.1 v3 11/26] target/riscv/cpu.c: set cpu config in set_misa()

[Daniel Henrique Barboza]

set_misa() is setting all 'misa' related env states and nothing else.
But other functions, namely riscv_cpu_validate_set_extensions(), uses
the config object to do its job.

This creates a need to set the single letter extensions in the cfg
object to keep both in sync. At this moment this is being done by
register_cpu_props(), forcing every CPU to do a call to this function.

Let's beef up set_misa() and make the function do the sync for us. This
will relieve named CPUs to having to call register_cpu_props(), which
will then be redesigned to a more specialized role next.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 40 ++++++++++++++++++++++++++++++++--------
 target/riscv/cpu.h |  4 ++--
 2 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 36c55abda0..7841676473 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -236,8 +236,40 @@ const char *riscv_cpu_get_trap_name(target_ulong cause, bool async)
 
 static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
 {
+    RISCVCPU *cpu;
+
     env->misa_mxl_max = env->misa_mxl = mxl;
     env->misa_ext_mask = env->misa_ext = ext;
+
+    /*
+     * ext = 0 will only be a thing during cpu_init() functions
+     * as a way of setting an extension-agnostic CPU. We do
+     * not support clearing misa_ext* and the ext_N flags in
+     * RISCVCPUConfig in regular circunstances.
+     */
+    if (ext == 0) {
+        return;
+    }
+
+    /*
+     * We can't use riscv_cpu_cfg() in this case because it is
+     * a read-only inline and we're going to change the values
+     * of cpu->cfg.
+     */
+    cpu = env_archcpu(env);
+
+    cpu->cfg.ext_i = ext & RVI;
+    cpu->cfg.ext_e = ext & RVE;
+    cpu->cfg.ext_m = ext & RVM;
+    cpu->cfg.ext_a = ext & RVA;
+    cpu->cfg.ext_f = ext & RVF;
+    cpu->cfg.ext_d = ext & RVD;
+    cpu->cfg.ext_v = ext & RVV;
+    cpu->cfg.ext_c = ext & RVC;
+    cpu->cfg.ext_s = ext & RVS;
+    cpu->cfg.ext_u = ext & RVU;
+    cpu->cfg.ext_h = ext & RVH;
+    cpu->cfg.ext_j = ext & RVJ;
 }
 
 #ifndef CONFIG_USER_ONLY
@@ -340,7 +372,6 @@ static void riscv_any_cpu_init(Object *obj)
 #endif
 
     env->priv_ver = PRIV_VERSION_LATEST;
-    register_cpu_props(obj);
 
     /* inherited from parent obj via riscv_cpu_init() */
     cpu->cfg.ext_ifencei = true;
@@ -368,7 +399,6 @@ static void rv64_sifive_u_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
     CPURISCVState *env = &cpu->env;
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
-    register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV39);
@@ -387,7 +417,6 @@ static void rv64_sifive_e_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
 
     set_misa(env, MXL_RV64, RVI | RVM | RVA | RVC | RVU);
-    register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -472,8 +501,6 @@ static void rv32_sifive_u_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
     CPURISCVState *env = &cpu->env;
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
-
-    register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
@@ -492,7 +519,6 @@ static void rv32_sifive_e_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
 
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVC | RVU);
-    register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -510,7 +536,6 @@ static void rv32_ibex_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
 
     set_misa(env, MXL_RV32, RVI | RVM | RVC | RVU);
-    register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_11_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
@@ -529,7 +554,6 @@ static void rv32_imafcu_nommu_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
 
     set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVC | RVU);
-    register_cpu_props(obj);
     env->priv_ver = PRIV_VERSION_1_10_0;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 76f81c6b68..ebe0fff668 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -66,8 +66,8 @@
 #define RV(x) ((target_ulong)1 << (x - 'A'))
 
 /*
- * Consider updating register_cpu_props() when adding
- * new MISA bits here.
+ * Consider updating set_misa() when adding new
+ * MISA bits here.
  */
 #define RVI RV('I')
 #define RVE RV('E') /* E and I are mutually exclusive */
-- 
2.39.2

Re: [PATCH for-8.1 v3 11/26] target/riscv/cpu.c: set cpu config in set_misa()

[liweiwei]

[-- Attachment #1: Type: text/plain, Size: 5414 bytes --]


On 2023/3/19 04:04, Daniel Henrique Barboza wrote:
> set_misa() is setting all 'misa' related env states and nothing else.
> But other functions, namely riscv_cpu_validate_set_extensions(), uses
> the config object to do its job.
>
> This creates a need to set the single letter extensions in the cfg
> object to keep both in sync. At this moment this is being done by
> register_cpu_props(), forcing every CPU to do a call to this function.
>
> Let's beef up set_misa() and make the function do the sync for us. This
> will relieve named CPUs to having to call register_cpu_props(), which
> will then be redesigned to a more specialized role next.
>
> Signed-off-by: Daniel Henrique Barboza<dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 40 ++++++++++++++++++++++++++++++++--------
>   target/riscv/cpu.h |  4 ++--
>   2 files changed, 34 insertions(+), 10 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 36c55abda0..7841676473 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -236,8 +236,40 @@ const char *riscv_cpu_get_trap_name(target_ulong cause, bool async)
>   
>   static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
>   {
> +    RISCVCPU *cpu;
> +
>       env->misa_mxl_max = env->misa_mxl = mxl;
>       env->misa_ext_mask = env->misa_ext = ext;
> +
> +    /*
> +     * ext = 0 will only be a thing during cpu_init() functions
> +     * as a way of setting an extension-agnostic CPU. We do
> +     * not support clearing misa_ext* and the ext_N flags in
> +     * RISCVCPUConfig in regular circunstances.
> +     */
> +    if (ext == 0) {
> +        return;
> +    }
> +
> +    /*
> +     * We can't use riscv_cpu_cfg() in this case because it is
> +     * a read-only inline and we're going to change the values
> +     * of cpu->cfg.
> +     */
> +    cpu = env_archcpu(env);
> +
> +    cpu->cfg.ext_i = ext & RVI;
> +    cpu->cfg.ext_e = ext & RVE;
> +    cpu->cfg.ext_m = ext & RVM;
> +    cpu->cfg.ext_a = ext & RVA;
> +    cpu->cfg.ext_f = ext & RVF;
> +    cpu->cfg.ext_d = ext & RVD;
> +    cpu->cfg.ext_v = ext & RVV;
> +    cpu->cfg.ext_c = ext & RVC;
> +    cpu->cfg.ext_s = ext & RVS;
> +    cpu->cfg.ext_u = ext & RVU;
> +    cpu->cfg.ext_h = ext & RVH;
> +    cpu->cfg.ext_j = ext & RVJ;
>   }
>   
>   #ifndef CONFIG_USER_ONLY
> @@ -340,7 +372,6 @@ static void riscv_any_cpu_init(Object *obj)
>   #endif
>   
>       env->priv_ver = PRIV_VERSION_LATEST;
> -    register_cpu_props(obj);
>   
>       /* inherited from parent obj via riscv_cpu_init() */
>       cpu->cfg.ext_ifencei = true;
> @@ -368,7 +399,6 @@ static void rv64_sifive_u_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>       CPURISCVState *env = &cpu->env;
>       set_misa(env, MXL_RV64, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
> -    register_cpu_props(obj);
>       env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV39);
> @@ -387,7 +417,6 @@ static void rv64_sifive_e_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>   
>       set_misa(env, MXL_RV64, RVI | RVM | RVA | RVC | RVU);
> -    register_cpu_props(obj);
>       env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -472,8 +501,6 @@ static void rv32_sifive_u_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>       CPURISCVState *env = &cpu->env;
>       set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
> -
> -    register_cpu_props(obj);
>       env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(RISCV_CPU(obj), VM_1_10_SV32);
> @@ -492,7 +519,6 @@ static void rv32_sifive_e_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>   
>       set_misa(env, MXL_RV32, RVI | RVM | RVA | RVC | RVU);
> -    register_cpu_props(obj);
>       env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -510,7 +536,6 @@ static void rv32_ibex_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>   
>       set_misa(env, MXL_RV32, RVI | RVM | RVC | RVU);
> -    register_cpu_props(obj);
>       env->priv_ver = PRIV_VERSION_1_11_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> @@ -529,7 +554,6 @@ static void rv32_imafcu_nommu_cpu_init(Object *obj)
>       RISCVCPU *cpu = RISCV_CPU(obj);
>   
>       set_misa(env, MXL_RV32, RVI | RVM | RVA | RVF | RVC | RVU);
> -    register_cpu_props(obj);
>       env->priv_ver = PRIV_VERSION_1_10_0;
>   #ifndef CONFIG_USER_ONLY
>       set_satp_mode_max_supported(cpu, VM_1_10_MBARE);
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 76f81c6b68..ebe0fff668 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -66,8 +66,8 @@
>   #define RV(x) ((target_ulong)1 << (x - 'A'))
>   
>   /*
> - * Consider updating register_cpu_props() when adding
> - * new MISA bits here.
> + * Consider updating set_misa() when adding new
> + * MISA bits here.
>    */
>   #define RVI RV('I')
>   #define RVE RV('E') /* E and I are mutually exclusive */

The assignment for ext_c/u/s in rv64_thead_c906_cpu_init can be removed, 
since all of them have

be done in set_misa.

Similar to ext_g, if RVG is added.

Regards,

Weiwei Li

[-- Attachment #2: Type: text/html, Size: 6106 bytes --]

[PATCH for-8.1 v3 12/26] target/riscv/cpu.c: redesign register_cpu_props()

[Daniel Henrique Barboza]

Now that the function is a no-op if 'env.misa_ext != 0', and no one that
are setting misa_ext != 0 is calling it because set_misa() is setting
the cpu cfg accordingly, remove the now deprecated code and rename the
function to register_generic_cpu_props().

This function is now doing exactly what the name says: it is creating
user-facing properties to allow changes in the CPU cfg via the QEMU
command line, setting default values if no user input is provided.

Note that there's the possibility of a CPU to set a certain misa value
and, at the same, also want user-facing flags and defaults from this
function. This is not the case since commit 26b2bc58599c ("target/riscv:
Don't expose the CPU properties on names CPUs"), but given that this is
also a possibility, clarify in the function that using this function
will overwrite existing values in cpu->cfg.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 48 ++++++++++------------------------------------
 1 file changed, 10 insertions(+), 38 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 7841676473..6b5096d25e 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -221,7 +221,7 @@ static const char * const riscv_intr_names[] = {
     "reserved"
 };
 
-static void register_cpu_props(Object *obj);
+static void register_generic_cpu_props(Object *obj);
 
 const char *riscv_cpu_get_trap_name(target_ulong cause, bool async)
 {
@@ -386,7 +386,7 @@ static void rv64_base_cpu_init(Object *obj)
     CPURISCVState *env = &RISCV_CPU(obj)->env;
     /* We set this in the realise function */
     set_misa(env, MXL_RV64, 0);
-    register_cpu_props(obj);
+    register_generic_cpu_props(obj);
     /* Set latest version of privileged specification */
     env->priv_ver = PRIV_VERSION_LATEST;
 #ifndef CONFIG_USER_ONLY
@@ -475,7 +475,7 @@ static void rv128_base_cpu_init(Object *obj)
     CPURISCVState *env = &RISCV_CPU(obj)->env;
     /* We set this in the realise function */
     set_misa(env, MXL_RV128, 0);
-    register_cpu_props(obj);
+    register_generic_cpu_props(obj);
     /* Set latest version of privileged specification */
     env->priv_ver = PRIV_VERSION_LATEST;
 #ifndef CONFIG_USER_ONLY
@@ -488,7 +488,7 @@ static void rv32_base_cpu_init(Object *obj)
     CPURISCVState *env = &RISCV_CPU(obj)->env;
     /* We set this in the realise function */
     set_misa(env, MXL_RV32, 0);
-    register_cpu_props(obj);
+    register_generic_cpu_props(obj);
     /* Set latest version of privileged specification */
     env->priv_ver = PRIV_VERSION_LATEST;
 #ifndef CONFIG_USER_ONLY
@@ -575,7 +575,7 @@ static void riscv_host_cpu_init(Object *obj)
 #elif defined(TARGET_RISCV64)
     set_misa(env, MXL_RV64, 0);
 #endif
-    register_cpu_props(obj);
+    register_generic_cpu_props(obj);
 }
 #endif
 
@@ -1557,44 +1557,16 @@ static Property riscv_cpu_extensions[] = {
 };
 
 /*
- * Register CPU props based on env.misa_ext. If a non-zero
- * value was set, register only the required cpu->cfg.ext_*
- * properties and leave. env.misa_ext = 0 means that we want
- * all the default properties to be registered.
+ * Register generic CPU props with user-facing flags declared
+ * in riscv_cpu_extensions[].
+ *
+ * Note that this will overwrite existing values in cpu->cfg.
  */
-static void register_cpu_props(Object *obj)
+static void register_generic_cpu_props(Object *obj)
 {
-    RISCVCPU *cpu = RISCV_CPU(obj);
-    uint32_t misa_ext = cpu->env.misa_ext;
     Property *prop;
     DeviceState *dev = DEVICE(obj);
 
-    /*
-     * If misa_ext is not zero, set cfg properties now to
-     * allow them to be read during riscv_cpu_realize()
-     * later on.
-     */
-    if (cpu->env.misa_ext != 0) {
-        cpu->cfg.ext_i = misa_ext & RVI;
-        cpu->cfg.ext_e = misa_ext & RVE;
-        cpu->cfg.ext_m = misa_ext & RVM;
-        cpu->cfg.ext_a = misa_ext & RVA;
-        cpu->cfg.ext_f = misa_ext & RVF;
-        cpu->cfg.ext_d = misa_ext & RVD;
-        cpu->cfg.ext_v = misa_ext & RVV;
-        cpu->cfg.ext_c = misa_ext & RVC;
-        cpu->cfg.ext_s = misa_ext & RVS;
-        cpu->cfg.ext_u = misa_ext & RVU;
-        cpu->cfg.ext_h = misa_ext & RVH;
-        cpu->cfg.ext_j = misa_ext & RVJ;
-
-        /*
-         * We don't want to set the default riscv_cpu_extensions
-         * in this case.
-         */
-        return;
-    }
-
     for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
         qdev_property_add_static(dev, prop);
     }
-- 
2.39.2

[PATCH for-8.1 v3 13/26] target/riscv: put env->misa_ext <-> cpu->cfg code into helpers

[Daniel Henrique Barboza]

The extremely tedious code that sets cpu->cfg based on misa_ext, and
vice-versa, is scattered around riscv_cpu_validate_set_extensions() and
set_misa().

Introduce helpers to do this work, cleaning up the logic of both
functions a bit. While we're at it, add a note in cpu.h informing that
any future change in MISA RV* bits should also be reflected in the
helpers as well.

We'll want to keep env->misa_ext changes in sync with cpu->cfg during
realize() in the next patches, and both helpers will have a role to play
in that.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 120 ++++++++++++++++++++++++---------------------
 target/riscv/cpu.h |   3 +-
 2 files changed, 65 insertions(+), 58 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 6b5096d25e..28d4c5f768 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -234,10 +234,69 @@ const char *riscv_cpu_get_trap_name(target_ulong cause, bool async)
     }
 }
 
-static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
+static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
 {
-    RISCVCPU *cpu;
+    uint32_t ext = 0;
 
+    if (cfg->ext_i) {
+        ext |= RVI;
+    }
+    if (cfg->ext_e) {
+        ext |= RVE;
+    }
+    if (cfg->ext_m) {
+        ext |= RVM;
+    }
+    if (cfg->ext_a) {
+        ext |= RVA;
+    }
+    if (cfg->ext_f) {
+        ext |= RVF;
+    }
+    if (cfg->ext_d) {
+        ext |= RVD;
+    }
+    if (cfg->ext_c) {
+        ext |= RVC;
+    }
+    if (cfg->ext_s) {
+        ext |= RVS;
+    }
+    if (cfg->ext_u) {
+        ext |= RVU;
+    }
+    if (cfg->ext_h) {
+        ext |= RVH;
+    }
+    if (cfg->ext_v) {
+        ext |= RVV;
+    }
+    if (cfg->ext_j) {
+        ext |= RVJ;
+    }
+
+    return ext;
+}
+
+static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
+                                       uint32_t misa_ext)
+{
+    cfg->ext_i = misa_ext & RVI;
+    cfg->ext_e = misa_ext & RVE;
+    cfg->ext_m = misa_ext & RVM;
+    cfg->ext_a = misa_ext & RVA;
+    cfg->ext_f = misa_ext & RVF;
+    cfg->ext_d = misa_ext & RVD;
+    cfg->ext_v = misa_ext & RVV;
+    cfg->ext_c = misa_ext & RVC;
+    cfg->ext_s = misa_ext & RVS;
+    cfg->ext_u = misa_ext & RVU;
+    cfg->ext_h = misa_ext & RVH;
+    cfg->ext_j = misa_ext & RVJ;
+}
+
+static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
+{
     env->misa_mxl_max = env->misa_mxl = mxl;
     env->misa_ext_mask = env->misa_ext = ext;
 
@@ -251,25 +310,7 @@ static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
         return;
     }
 
-    /*
-     * We can't use riscv_cpu_cfg() in this case because it is
-     * a read-only inline and we're going to change the values
-     * of cpu->cfg.
-     */
-    cpu = env_archcpu(env);
-
-    cpu->cfg.ext_i = ext & RVI;
-    cpu->cfg.ext_e = ext & RVE;
-    cpu->cfg.ext_m = ext & RVM;
-    cpu->cfg.ext_a = ext & RVA;
-    cpu->cfg.ext_f = ext & RVF;
-    cpu->cfg.ext_d = ext & RVD;
-    cpu->cfg.ext_v = ext & RVV;
-    cpu->cfg.ext_c = ext & RVC;
-    cpu->cfg.ext_s = ext & RVS;
-    cpu->cfg.ext_u = ext & RVU;
-    cpu->cfg.ext_h = ext & RVH;
-    cpu->cfg.ext_j = ext & RVJ;
+    riscv_set_cpucfg_with_misa(&env_archcpu(env)->cfg, ext);
 }
 
 #ifndef CONFIG_USER_ONLY
@@ -1156,42 +1197,7 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
      */
     riscv_cpu_disable_priv_spec_isa_exts(cpu);
 
-    if (cpu->cfg.ext_i) {
-        ext |= RVI;
-    }
-    if (cpu->cfg.ext_e) {
-        ext |= RVE;
-    }
-    if (cpu->cfg.ext_m) {
-        ext |= RVM;
-    }
-    if (cpu->cfg.ext_a) {
-        ext |= RVA;
-    }
-    if (cpu->cfg.ext_f) {
-        ext |= RVF;
-    }
-    if (cpu->cfg.ext_d) {
-        ext |= RVD;
-    }
-    if (cpu->cfg.ext_c) {
-        ext |= RVC;
-    }
-    if (cpu->cfg.ext_s) {
-        ext |= RVS;
-    }
-    if (cpu->cfg.ext_u) {
-        ext |= RVU;
-    }
-    if (cpu->cfg.ext_h) {
-        ext |= RVH;
-    }
-    if (cpu->cfg.ext_v) {
-        ext |= RVV;
-    }
-    if (cpu->cfg.ext_j) {
-        ext |= RVJ;
-    }
+    ext = riscv_get_misa_ext_with_cpucfg(&cpu->cfg);
 
     env->misa_ext_mask = env->misa_ext = ext;
 }
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index ebe0fff668..2263629332 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -66,7 +66,8 @@
 #define RV(x) ((target_ulong)1 << (x - 'A'))
 
 /*
- * Consider updating set_misa() when adding new
+ * Consider updating riscv_get_misa_ext_with_cpucfg()
+ * and riscv_set_cpucfg_with_misa() when adding new
  * MISA bits here.
  */
 #define RVI RV('I')
-- 
2.39.2

[PATCH for-8.1 v3 14/26] target/riscv: add RVG

[Daniel Henrique Barboza]

The 'G' bit in misa_ext is a virtual extension that enables a set of
extensions (i, m, a, f, d, icsr and ifencei). We're already have code to
handle it but no bit definition. Add it.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 4 ++++
 target/riscv/cpu.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 28d4c5f768..48ad7372b9 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -274,6 +274,9 @@ static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
     if (cfg->ext_j) {
         ext |= RVJ;
     }
+    if (cfg->ext_g) {
+        ext |= RVG;
+    }
 
     return ext;
 }
@@ -293,6 +296,7 @@ static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
     cfg->ext_u = misa_ext & RVU;
     cfg->ext_h = misa_ext & RVH;
     cfg->ext_j = misa_ext & RVJ;
+    cfg->ext_g = misa_ext & RVG;
 }
 
 static void set_misa(CPURISCVState *env, RISCVMXL mxl, uint32_t ext)
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 2263629332..dbb4df9df0 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -82,6 +82,7 @@
 #define RVU RV('U')
 #define RVH RV('H')
 #define RVJ RV('J')
+#define RVG RV('G')
 
 
 /* Privileged specification version */
-- 
2.39.2

[PATCH for-8.1 v3 15/26] target/riscv/cpu.c: split RVG code from validate_set_extensions()

[Daniel Henrique Barboza]

We can set all RVG related extensions during realize time, before
validate_set_extensions() itself. Put it in a separated function so the
validate function already uses the updated state.

Note that we're adding an extra constraint: ext_zfinx is a blocker for
F, which is a requirement to enable G. If zfinx is enabled we'll have to
error out.

Note that we're setting both cfg->ext_N and env->misa_ext bits, instead
of just setting cfg->ext_N. The intention here is to start syncing all
misa_ext operations with its cpu->cfg flags, in preparation to allow for
the validate function to operate using a misa_ext. This doesn't make any
difference for the current code state, but will be a requirement for
write_misa() later on.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 66 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 51 insertions(+), 15 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 48ad7372b9..110b52712c 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -281,6 +281,42 @@ static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
     return ext;
 }
 
+static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
+{
+    CPURISCVState *env = &cpu->env;
+    RISCVCPUConfig *cfg = &cpu->cfg;
+
+    if (cpu->cfg.ext_zfinx) {
+        error_setg(errp, "Unable to enable G: Zfinx is enabled, "
+                         "so F can not be enabled");
+        return;
+    }
+
+    if (!(cfg->ext_i && cfg->ext_m && cfg->ext_a &&
+          cfg->ext_f && cfg->ext_d &&
+          cfg->ext_icsr && cfg->ext_ifencei)) {
+
+        warn_report("Setting G will also set IMAFD_Zicsr_Zifencei");
+        cfg->ext_i = true;
+        env->misa_ext |= RVI;
+
+        cfg->ext_m = true;
+        env->misa_ext |= RVM;
+
+        cfg->ext_a = true;
+        env->misa_ext |= RVA;
+
+        cfg->ext_f = true;
+        env->misa_ext |= RVF;
+
+        cfg->ext_d = true;
+        env->misa_ext |= RVD;
+
+        cfg->ext_icsr = true;
+        cfg->ext_ifencei = true;
+    }
+}
+
 static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
                                        uint32_t misa_ext)
 {
@@ -1036,21 +1072,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    /* Do some ISA extension error checking */
-    if (cpu->cfg.ext_g && !(cpu->cfg.ext_i && cpu->cfg.ext_m &&
-                            cpu->cfg.ext_a && cpu->cfg.ext_f &&
-                            cpu->cfg.ext_d &&
-                            cpu->cfg.ext_icsr && cpu->cfg.ext_ifencei)) {
-        warn_report("Setting G will also set IMAFD_Zicsr_Zifencei");
-        cpu->cfg.ext_i = true;
-        cpu->cfg.ext_m = true;
-        cpu->cfg.ext_a = true;
-        cpu->cfg.ext_f = true;
-        cpu->cfg.ext_d = true;
-        cpu->cfg.ext_icsr = true;
-        cpu->cfg.ext_ifencei = true;
-    }
-
     if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
         error_setg(errp,
                    "I and E extensions are incompatible");
@@ -1293,6 +1314,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     CPUState *cs = CPU(dev);
     RISCVCPU *cpu = RISCV_CPU(dev);
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
+    CPURISCVState *env = &cpu->env;
     Error *local_err = NULL;
 
     cpu_exec_realizefn(cs, &local_err);
@@ -1313,6 +1335,20 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    if (cpu->cfg.ext_g) {
+        riscv_cpu_enable_g(cpu, &local_err);
+        if (local_err != NULL) {
+            error_propagate(errp, local_err);
+            return;
+        }
+
+        /*
+         * Sync env->misa_ext_mask with the new
+         * env->misa_ext val.
+         */
+        env->misa_ext_mask = env->misa_ext;
+    }
+
     riscv_cpu_validate_set_extensions(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-- 
2.39.2

Re: [PATCH for-8.1 v3 15/26] target/riscv/cpu.c: split RVG code from validate_set_extensions()

[liweiwei]

On 2023/3/19 04:04, Daniel Henrique Barboza wrote:
> We can set all RVG related extensions during realize time, before
> validate_set_extensions() itself. Put it in a separated function so the
> validate function already uses the updated state.
>
> Note that we're adding an extra constraint: ext_zfinx is a blocker for
> F, which is a requirement to enable G. If zfinx is enabled we'll have to
> error out.
>
> Note that we're setting both cfg->ext_N and env->misa_ext bits, instead
> of just setting cfg->ext_N. The intention here is to start syncing all
> misa_ext operations with its cpu->cfg flags, in preparation to allow for
> the validate function to operate using a misa_ext. This doesn't make any
> difference for the current code state, but will be a requirement for
> write_misa() later on.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 66 +++++++++++++++++++++++++++++++++++-----------
>   1 file changed, 51 insertions(+), 15 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 48ad7372b9..110b52712c 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -281,6 +281,42 @@ static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
>       return ext;
>   }
>   
> +static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
> +{
> +    CPURISCVState *env = &cpu->env;
> +    RISCVCPUConfig *cfg = &cpu->cfg;
> +
> +    if (cpu->cfg.ext_zfinx) {
> +        error_setg(errp, "Unable to enable G: Zfinx is enabled, "
> +                         "so F can not be enabled");
> +        return;
> +    }

This check is not very necessary here, since check Zfinx against F will 
be done in following code.

Regards,

Weiwei Li

> +
> +    if (!(cfg->ext_i && cfg->ext_m && cfg->ext_a &&
> +          cfg->ext_f && cfg->ext_d &&
> +          cfg->ext_icsr && cfg->ext_ifencei)) {
> +
> +        warn_report("Setting G will also set IMAFD_Zicsr_Zifencei");
> +        cfg->ext_i = true;
> +        env->misa_ext |= RVI;
> +
> +        cfg->ext_m = true;
> +        env->misa_ext |= RVM;
> +
> +        cfg->ext_a = true;
> +        env->misa_ext |= RVA;
> +
> +        cfg->ext_f = true;
> +        env->misa_ext |= RVF;
> +
> +        cfg->ext_d = true;
> +        env->misa_ext |= RVD;
> +
> +        cfg->ext_icsr = true;
> +        cfg->ext_ifencei = true;
> +    }
> +}
> +
>   static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
>                                          uint32_t misa_ext)
>   {
> @@ -1036,21 +1072,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>           return;
>       }
>   
> -    /* Do some ISA extension error checking */
> -    if (cpu->cfg.ext_g && !(cpu->cfg.ext_i && cpu->cfg.ext_m &&
> -                            cpu->cfg.ext_a && cpu->cfg.ext_f &&
> -                            cpu->cfg.ext_d &&
> -                            cpu->cfg.ext_icsr && cpu->cfg.ext_ifencei)) {
> -        warn_report("Setting G will also set IMAFD_Zicsr_Zifencei");
> -        cpu->cfg.ext_i = true;
> -        cpu->cfg.ext_m = true;
> -        cpu->cfg.ext_a = true;
> -        cpu->cfg.ext_f = true;
> -        cpu->cfg.ext_d = true;
> -        cpu->cfg.ext_icsr = true;
> -        cpu->cfg.ext_ifencei = true;
> -    }
> -
>       if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
>           error_setg(errp,
>                      "I and E extensions are incompatible");
> @@ -1293,6 +1314,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
>       CPUState *cs = CPU(dev);
>       RISCVCPU *cpu = RISCV_CPU(dev);
>       RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
> +    CPURISCVState *env = &cpu->env;
>       Error *local_err = NULL;
>   
>       cpu_exec_realizefn(cs, &local_err);
> @@ -1313,6 +1335,20 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
>           return;
>       }
>   
> +    if (cpu->cfg.ext_g) {
> +        riscv_cpu_enable_g(cpu, &local_err);
> +        if (local_err != NULL) {
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +
> +        /*
> +         * Sync env->misa_ext_mask with the new
> +         * env->misa_ext val.
> +         */
> +        env->misa_ext_mask = env->misa_ext;
> +    }
> +
>       riscv_cpu_validate_set_extensions(cpu, &local_err);
>       if (local_err != NULL) {
>           error_propagate(errp, local_err);

[PATCH for-8.1 v3 16/26] target/riscv/cpu.c: add riscv_cpu_validate_misa_ext()

[Daniel Henrique Barboza]

Even after taking RVG off from riscv_cpu_validate_set_extensions(), the
function is still doing too much. It is validating misa bits, then
validating named extensions, and if the validation succeeds it's doing
more changes in both cpu->cfg and MISA bits.

It works for the support we have today, since we'll error out during
realize() time. This is not enough to support write_misa() though - we
don't want to error out if userspace writes something odd in the CSR.

This patch starts splitting riscv_cpu_validate_set_extensions() into a
three step process: validate misa_ext, validate cpu->cfg, then commit
the configuration. This separation will allow us to use these functions
in write_misa() without having to worry about saving CPU state during
runtime because the function changed state but failed to validate.

riscv_cpu_validate_misa_ext() will host all validations related to misa
bits only. Validations using misa bits + name extensions will remain in
validate_set_extensions().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 77 ++++++++++++++++++++++++++--------------------
 1 file changed, 43 insertions(+), 34 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 110b52712c..c7b05d7c4e 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1025,6 +1025,43 @@ static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
     }
 }
 
+static void riscv_cpu_validate_misa_ext(RISCVCPU *cpu, Error **errp)
+{
+    if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
+        error_setg(errp,
+                   "I and E extensions are incompatible");
+        return;
+    }
+
+    if (!cpu->cfg.ext_i && !cpu->cfg.ext_e) {
+        error_setg(errp,
+                   "Either I or E extension must be set");
+        return;
+    }
+
+    if (cpu->cfg.ext_s && !cpu->cfg.ext_u) {
+        error_setg(errp,
+                   "Setting S extension without U extension is illegal");
+        return;
+    }
+
+    if (cpu->cfg.ext_h && !cpu->cfg.ext_i) {
+        error_setg(errp,
+                   "H depends on an I base integer ISA with 32 x registers");
+        return;
+    }
+
+    if (cpu->cfg.ext_h && !cpu->cfg.ext_s) {
+        error_setg(errp, "H extension implicitly requires S-mode");
+        return;
+    }
+
+    if (cpu->cfg.ext_d && !cpu->cfg.ext_f) {
+        error_setg(errp, "D extension requires F extension");
+        return;
+    }
+}
+
 static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
 {
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(cpu);
@@ -1072,35 +1109,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
-        error_setg(errp,
-                   "I and E extensions are incompatible");
-        return;
-    }
-
-    if (!cpu->cfg.ext_i && !cpu->cfg.ext_e) {
-        error_setg(errp,
-                   "Either I or E extension must be set");
-        return;
-    }
-
-    if (cpu->cfg.ext_s && !cpu->cfg.ext_u) {
-        error_setg(errp,
-                   "Setting S extension without U extension is illegal");
-        return;
-    }
-
-    if (cpu->cfg.ext_h && !cpu->cfg.ext_i) {
-        error_setg(errp,
-                   "H depends on an I base integer ISA with 32 x registers");
-        return;
-    }
-
-    if (cpu->cfg.ext_h && !cpu->cfg.ext_s) {
-        error_setg(errp, "H extension implicitly requires S-mode");
-        return;
-    }
-
     if (cpu->cfg.ext_f && !cpu->cfg.ext_icsr) {
         error_setg(errp, "F extension requires Zicsr");
         return;
@@ -1120,11 +1128,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (cpu->cfg.ext_d && !cpu->cfg.ext_f) {
-        error_setg(errp, "D extension requires F extension");
-        return;
-    }
-
     /* The V vector extension depends on the Zve64d extension */
     if (cpu->cfg.ext_v) {
         cpu->cfg.ext_zve64d = true;
@@ -1349,6 +1352,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         env->misa_ext_mask = env->misa_ext;
     }
 
+    riscv_cpu_validate_misa_ext(cpu, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
     riscv_cpu_validate_set_extensions(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-- 
2.39.2

[PATCH for-8.1 v3 17/26] target/riscv: move riscv_cpu_validate_v() to validate_misa_ext()

[Daniel Henrique Barboza]

riscv_cpu_validate_v() consists of checking RVV related attributes, such
as vlen and elen, and setting env->vext_spec.

This can be done during riscv_cpu_validate_misa_ext() time, allowing us
to fail earlier if RVV constrains are not met.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index c7b05d7c4e..1116686cd1 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1027,6 +1027,9 @@ static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
 
 static void riscv_cpu_validate_misa_ext(RISCVCPU *cpu, Error **errp)
 {
+    CPURISCVState *env = &cpu->env;
+    Error *local_err = NULL;
+
     if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
         error_setg(errp,
                    "I and E extensions are incompatible");
@@ -1060,6 +1063,14 @@ static void riscv_cpu_validate_misa_ext(RISCVCPU *cpu, Error **errp)
         error_setg(errp, "D extension requires F extension");
         return;
     }
+
+    if (cpu->cfg.ext_v) {
+        riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
+        if (local_err != NULL) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
 }
 
 static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
@@ -1097,7 +1108,6 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
 static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
 {
     CPURISCVState *env = &cpu->env;
-    Error *local_err = NULL;
     uint32_t ext = 0;
 
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
@@ -1188,14 +1198,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         }
     }
 
-    if (cpu->cfg.ext_v) {
-        riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
-        if (local_err != NULL) {
-            error_propagate(errp, local_err);
-            return;
-        }
-    }
-
     if (cpu->cfg.ext_zk) {
         cpu->cfg.ext_zkn = true;
         cpu->cfg.ext_zkr = true;
-- 
2.39.2

[PATCH for-8.1 v3 18/26] target/riscv: error out on priv failure for RVH

[Daniel Henrique Barboza]

riscv_cpu_disable_priv_spec_isa_exts(), at the end of
riscv_cpu_validate_set_extensions(), will disable cpu->cfg.ext_h and
cpu->cfg.ext_v if priv_ver check fails.

This check can be done in riscv_cpu_validate_misa_ext(). The difference
here is that we're not silently disable it: we'll error out. Silently
disabling a MISA extension after all the validation is completed can can
cause inconsistencies that we don't have to deal with. Verify ealier and
fail faster.

Note that we're ignoring RVV priv_ver validation since its minimal priv
is also the minimal value we support. RVH will error out if enabled
under priv_ver under 1_12_0.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 1116686cd1..d8f2eca6ca 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1064,6 +1064,20 @@ static void riscv_cpu_validate_misa_ext(RISCVCPU *cpu, Error **errp)
         return;
     }
 
+    /*
+     * Check for priv spec version. RVH is 1_12_0, RVV is 1_10_0.
+     * We don't support anything under 1_10_0 so skip checking
+     * priv for RVV.
+     *
+     * We're hardcoding it here to avoid looping into the
+     * 50+ entries of isa_edata_arr[] just to check the RVH
+     * entry.
+     */
+    if (cpu->cfg.ext_h && env->priv_ver < PRIV_VERSION_1_12_0) {
+        error_setg(errp, "H extension requires priv spec 1.12.0");
+        return;
+    }
+
     if (cpu->cfg.ext_v) {
         riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
         if (local_err != NULL) {
-- 
2.39.2

[PATCH for-8.1 v3 19/26] target/riscv: write env->misa_ext* in register_generic_cpu_props()

[Daniel Henrique Barboza]

In the process of creating the user-facing flags in
register_generic_cpu_props() we're also setting default values for the
cpu->cfg flags that represents MISA bits.

Leaving it as is will cause a discrepancy between users of this function
(at this moment the non-named CPUs) and named CPUs. Named CPUs are using
set_misa() with a non-zero 'ext' value, writing cpu->cfg in the process.
They'll reach riscv_cpu_realize() in a state where env->misa_ext will
reflect cpu->cfg, allowing functions to choose whether to use
env->misa_ext or cpu->cfg to validate MISA bits.

If we guarantee that env->misa_ext will always reflect cpu->cfg at the
start of riscv_cpu_realize(), functions will be able to no longer rely
on cpu->cfg for MISA validation. This happens to be one blocker we have
to properly support write_misa().

Sync env->misa_ext* in register_generic_cpu_props(). After that, there
will be no more places where env->misa_ext needs to be sync back with
cpu->cfg, so remove the now obsolete code at the end of
riscv_cpu_validate_set_extensions().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index d8f2eca6ca..992edd1735 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1116,14 +1116,10 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
 
 /*
  * Check consistency between chosen extensions while setting
- * cpu->cfg accordingly, setting env->misa_ext and
- * misa_ext_mask in the end.
+ * cpu->cfg accordingly.
  */
 static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
 {
-    CPURISCVState *env = &cpu->env;
-    uint32_t ext = 0;
-
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
         /*
          * Enhanced PMP should only be available
@@ -1240,10 +1236,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
      * validated and set everything we need.
      */
     riscv_cpu_disable_priv_spec_isa_exts(cpu);
-
-    ext = riscv_get_misa_ext_with_cpucfg(&cpu->cfg);
-
-    env->misa_ext_mask = env->misa_ext = ext;
 }
 
 #ifndef CONFIG_USER_ONLY
@@ -1354,6 +1346,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    /*
+     * This is the last point where env->misa_ext* can
+     * be changed.
+     */
     if (cpu->cfg.ext_g) {
         riscv_cpu_enable_g(cpu, &local_err);
         if (local_err != NULL) {
@@ -1631,10 +1627,12 @@ static Property riscv_cpu_extensions[] = {
  * Register generic CPU props with user-facing flags declared
  * in riscv_cpu_extensions[].
  *
- * Note that this will overwrite existing values in cpu->cfg.
+ * Note that this will overwrite existing values in cpu->cfg
+ * and MISA.
  */
 static void register_generic_cpu_props(Object *obj)
 {
+    RISCVCPU *cpu = RISCV_CPU(obj);
     Property *prop;
     DeviceState *dev = DEVICE(obj);
 
@@ -1645,6 +1643,10 @@ static void register_generic_cpu_props(Object *obj)
 #ifndef CONFIG_USER_ONLY
     riscv_add_satp_mode_properties(obj);
 #endif
+
+    /* Keep env->misa_ext and misa_ext_mask updated */
+    cpu->env.misa_ext = riscv_get_misa_ext_with_cpucfg(&cpu->cfg);
+    cpu->env.misa_ext_mask = cpu->env.misa_ext;
 }
 
 static Property riscv_cpu_properties[] = {
-- 
2.39.2

[PATCH for-8.1 v3 20/26] target/riscv: make validate_misa_ext() use a misa_ext val

[Daniel Henrique Barboza]

We have all MISA specific validations in riscv_cpu_validate_misa_ext(),
and we have a guarantee that env->misa_ext will always be in sync with
cpu->cfg at this point during realize time, so let's convert it to use a
'misa_ext' parameter instead of reading cpu->cfg.

This will prepare the function to be used in write_misa() where we won't
have an updated cpu->cfg object to work with. riscv_cpu_validate_v() is
changed to receive a const pointer to the cpu->cfg object via
riscv_cpu_cfg().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 992edd1735..7861f0421e 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -939,7 +939,8 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
     }
 }
 
-static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
+static void riscv_cpu_validate_v(CPURISCVState *env,
+                                 const RISCVCPUConfig *cfg,
                                  Error **errp)
 {
     int vext_version = VEXT_VERSION_1_00_0;
@@ -1025,41 +1026,43 @@ static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
     }
 }
 
-static void riscv_cpu_validate_misa_ext(RISCVCPU *cpu, Error **errp)
+
+static void riscv_cpu_validate_misa_ext(CPURISCVState *env,
+                                        uint32_t misa_ext,
+                                        Error **errp)
 {
-    CPURISCVState *env = &cpu->env;
     Error *local_err = NULL;
 
-    if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
+    if (misa_ext & RVI && misa_ext & RVE) {
         error_setg(errp,
                    "I and E extensions are incompatible");
         return;
     }
 
-    if (!cpu->cfg.ext_i && !cpu->cfg.ext_e) {
+    if (!(misa_ext & RVI) && !(misa_ext & RVE)) {
         error_setg(errp,
                    "Either I or E extension must be set");
         return;
     }
 
-    if (cpu->cfg.ext_s && !cpu->cfg.ext_u) {
+    if (misa_ext & RVS && !(misa_ext & RVU)) {
         error_setg(errp,
                    "Setting S extension without U extension is illegal");
         return;
     }
 
-    if (cpu->cfg.ext_h && !cpu->cfg.ext_i) {
+    if (misa_ext & RVH && !(misa_ext & RVI)) {
         error_setg(errp,
                    "H depends on an I base integer ISA with 32 x registers");
         return;
     }
 
-    if (cpu->cfg.ext_h && !cpu->cfg.ext_s) {
+    if (misa_ext & RVH && !(misa_ext & RVS)) {
         error_setg(errp, "H extension implicitly requires S-mode");
         return;
     }
 
-    if (cpu->cfg.ext_d && !cpu->cfg.ext_f) {
+    if (misa_ext & RVD && !(misa_ext & RVF)) {
         error_setg(errp, "D extension requires F extension");
         return;
     }
@@ -1073,13 +1076,13 @@ static void riscv_cpu_validate_misa_ext(RISCVCPU *cpu, Error **errp)
      * 50+ entries of isa_edata_arr[] just to check the RVH
      * entry.
      */
-    if (cpu->cfg.ext_h && env->priv_ver < PRIV_VERSION_1_12_0) {
+    if (misa_ext & RVH && env->priv_ver < PRIV_VERSION_1_12_0) {
         error_setg(errp, "H extension requires priv spec 1.12.0");
         return;
     }
 
-    if (cpu->cfg.ext_v) {
-        riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
+    if (misa_ext & RVV) {
+        riscv_cpu_validate_v(env, riscv_cpu_cfg(env), &local_err);
         if (local_err != NULL) {
             error_propagate(errp, local_err);
             return;
@@ -1364,7 +1367,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         env->misa_ext_mask = env->misa_ext;
     }
 
-    riscv_cpu_validate_misa_ext(cpu, &local_err);
+    riscv_cpu_validate_misa_ext(env, env->misa_ext, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
         return;
-- 
2.39.2

[PATCH for-8.1 v3 21/26] target/riscv: split riscv_cpu_validate_set_extensions()

[Daniel Henrique Barboza]

We're now ready to split riscv_cpu_validate_set_extensions() in two.
None of these steps are going to touch env->misa_ext*.

riscv_cpu_validate_extensions() will take care of all validations based
on cpu->cfg values. cpu->cfg changes that are required for the
validation are being tolerated here. This is the case of extensions such
as ext_zfh enabling ext_zfhmin.

The RVV chain enablement (ext_zve64d, ext_zve64f and ext_zve32f) is also
being tolerated because the risk of failure is being mitigated by the
RVV -> RVD && RVF dependency in validate_misa_ext() done prior.

In an ideal world we would have all these extensions declared as object
properties, with getters and setters, and we would be able to, e.g.,
enable ext_zfhmin as soon as ext_zfh is enabled. This would avoid
cpu->cfg changes during riscv_cpu_validate_extensions(). Easier said
than done, not just because of the hundreds of lines involved in it, but
also because we want these properties to be available just for generic
CPUs (named CPUs don't want these properties exposed for users). For now
we'll work with that we have.

riscv_cpu_commit_cpu_cfg() is the last step of the validation where more
cpu->cfg properties are set and disabling of extensions due to priv spec
happens. We're already validated everything we wanted, so any cpu->cfg
change made here is valid.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 7861f0421e..69fc0d17a5 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1118,10 +1118,10 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
 }
 
 /*
- * Check consistency between chosen extensions while setting
- * cpu->cfg accordingly.
+ * Check consistency between chosen extensions. No changes
+ * in env->misa_ext are made.
  */
-static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
+static void riscv_cpu_validate_extensions(RISCVCPU *cpu, Error **errp)
 {
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
         /*
@@ -1210,7 +1210,10 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
             return;
         }
     }
+}
 
+static void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu)
+{
     if (cpu->cfg.ext_zk) {
         cpu->cfg.ext_zkn = true;
         cpu->cfg.ext_zkr = true;
@@ -1373,12 +1376,14 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    riscv_cpu_validate_set_extensions(cpu, &local_err);
+    riscv_cpu_validate_extensions(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
         return;
     }
 
+    riscv_cpu_commit_cpu_cfg(cpu);
+
 #ifndef CONFIG_USER_ONLY
     if (cpu->cfg.ext_sstc) {
         riscv_timer_init(cpu);
-- 
2.39.2

[PATCH for-8.1 v3 22/26] target/riscv: use misa_ext val in riscv_cpu_validate_extensions()

[Daniel Henrique Barboza]

Similar to what we did with riscv_cpu_validate_misa_ext(), let's read
all MISA bits from a misa_ext val instead of reading from the cpu->cfg
object.

This will allow write_misa() to use riscv_cpu_validate_extensions().

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 69fc0d17a5..e9172ec310 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1118,10 +1118,13 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
 }
 
 /*
- * Check consistency between chosen extensions. No changes
- * in env->misa_ext are made.
+ * Check consistency between cpu->cfg extensions and a
+ * candidate misa_ext value. No changes in env->misa_ext
+ * are made.
  */
-static void riscv_cpu_validate_extensions(RISCVCPU *cpu, Error **errp)
+static void riscv_cpu_validate_extensions(RISCVCPU *cpu,
+                                          uint32_t misa_ext,
+                                          Error **errp)
 {
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
         /*
@@ -1132,12 +1135,12 @@ static void riscv_cpu_validate_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (cpu->cfg.ext_f && !cpu->cfg.ext_icsr) {
+    if (misa_ext & RVF && !cpu->cfg.ext_icsr) {
         error_setg(errp, "F extension requires Zicsr");
         return;
     }
 
-    if ((cpu->cfg.ext_zawrs) && !cpu->cfg.ext_a) {
+    if ((cpu->cfg.ext_zawrs) && !(misa_ext & RVA)) {
         error_setg(errp, "Zawrs extension requires A extension");
         return;
     }
@@ -1146,13 +1149,13 @@ static void riscv_cpu_validate_extensions(RISCVCPU *cpu, Error **errp)
         cpu->cfg.ext_zfhmin = true;
     }
 
-    if (cpu->cfg.ext_zfhmin && !cpu->cfg.ext_f) {
+    if (cpu->cfg.ext_zfhmin && !(misa_ext & RVF)) {
         error_setg(errp, "Zfh/Zfhmin extensions require F extension");
         return;
     }
 
     /* The V vector extension depends on the Zve64d extension */
-    if (cpu->cfg.ext_v) {
+    if (misa_ext & RVV) {
         cpu->cfg.ext_zve64d = true;
     }
 
@@ -1166,12 +1169,12 @@ static void riscv_cpu_validate_extensions(RISCVCPU *cpu, Error **errp)
         cpu->cfg.ext_zve32f = true;
     }
 
-    if (cpu->cfg.ext_zve64d && !cpu->cfg.ext_d) {
+    if (cpu->cfg.ext_zve64d && !(misa_ext & RVD)) {
         error_setg(errp, "Zve64d/V extensions require D extension");
         return;
     }
 
-    if (cpu->cfg.ext_zve32f && !cpu->cfg.ext_f) {
+    if (cpu->cfg.ext_zve32f && !(misa_ext & RVF)) {
         error_setg(errp, "Zve32f/Zve64f extensions require F extension");
         return;
     }
@@ -1204,7 +1207,7 @@ static void riscv_cpu_validate_extensions(RISCVCPU *cpu, Error **errp)
             error_setg(errp, "Zfinx extension requires Zicsr");
             return;
         }
-        if (cpu->cfg.ext_f) {
+        if (misa_ext & RVF) {
             error_setg(errp,
                        "Zfinx cannot be supported together with F extension");
             return;
@@ -1376,7 +1379,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    riscv_cpu_validate_extensions(cpu, &local_err);
+    riscv_cpu_validate_extensions(cpu, env->misa_ext, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
         return;
-- 
2.39.2

[PATCH for-8.1 v3 23/26] target/riscv: rework write_misa()

[Daniel Henrique Barboza]

write_misa() must use as much common logic as possible. We want to open
code just the bits that are exclusive to the CSR write operation and TCG
internals.

Rewrite write_misa() to work as follows:

- mask the write using misa_ext_mask to avoid enabling unsupported
  extensions;

- suppress RVC if the next insn isn't aligned;

- handle RVE. This is done by filtering all bits but RVE from 'val'.
  Setting RVE will forcefully set only RVE - assuming it gets
  validated afterwards;

- emulate the steps done by realize(): validate the candidate misa_ext
  val, then validate the configuration with the candidate misa_ext val,
  and finally commit the changes to cpu->cfg.

If any of the validation steps fails, the write operation is a no-op.

Let's keep write_misa() as experimental for now until this logic gains
enough mileage.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 12 ++++------
 target/riscv/cpu.h |  6 +++++
 target/riscv/csr.c | 59 ++++++++++++++++++++++++++--------------------
 3 files changed, 45 insertions(+), 32 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index e9172ec310..67a46504bb 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1027,9 +1027,8 @@ static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
 }
 
 
-static void riscv_cpu_validate_misa_ext(CPURISCVState *env,
-                                        uint32_t misa_ext,
-                                        Error **errp)
+void riscv_cpu_validate_misa_ext(CPURISCVState *env, uint32_t misa_ext,
+                                 Error **errp)
 {
     Error *local_err = NULL;
 
@@ -1122,9 +1121,8 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
  * candidate misa_ext value. No changes in env->misa_ext
  * are made.
  */
-static void riscv_cpu_validate_extensions(RISCVCPU *cpu,
-                                          uint32_t misa_ext,
-                                          Error **errp)
+void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
+                                   Error **errp)
 {
     if (cpu->cfg.epmp && !cpu->cfg.pmp) {
         /*
@@ -1215,7 +1213,7 @@ static void riscv_cpu_validate_extensions(RISCVCPU *cpu,
     }
 }
 
-static void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu)
+void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu)
 {
     if (cpu->cfg.ext_zk) {
         cpu->cfg.ext_zkn = true;
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index dbb4df9df0..ca2ba6a647 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -593,6 +593,12 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
 char *riscv_isa_string(RISCVCPU *cpu);
 void riscv_cpu_list(void);
 
+void riscv_cpu_validate_misa_ext(CPURISCVState *env, uint32_t misa_ext,
+                                 Error **errp);
+void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
+                                   Error **errp);
+void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu);
+
 #define cpu_list riscv_cpu_list
 #define cpu_mmu_index riscv_cpu_mmu_index
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index d522efc0b6..8d5e8f9ad1 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1343,39 +1343,17 @@ static RISCVException read_misa(CPURISCVState *env, int csrno,
 static RISCVException write_misa(CPURISCVState *env, int csrno,
                                  target_ulong val)
 {
+    RISCVCPU *cpu = env_archcpu(env);
+    Error *local_err = NULL;
+
     if (!riscv_cpu_cfg(env)->misa_w) {
         /* drop write to misa */
         return RISCV_EXCP_NONE;
     }
 
-    /* 'I' or 'E' must be present */
-    if (!(val & (RVI | RVE))) {
-        /* It is not, drop write to misa */
-        return RISCV_EXCP_NONE;
-    }
-
-    /* 'E' excludes all other extensions */
-    if (val & RVE) {
-        /*
-         * when we support 'E' we can do "val = RVE;" however
-         * for now we just drop writes if 'E' is present.
-         */
-        return RISCV_EXCP_NONE;
-    }
-
-    /*
-     * misa.MXL writes are not supported by QEMU.
-     * Drop writes to those bits.
-     */
-
     /* Mask extensions that are not supported by this hart */
     val &= env->misa_ext_mask;
 
-    /* 'D' depends on 'F', so clear 'D' if 'F' is not present */
-    if ((val & RVD) && !(val & RVF)) {
-        val &= ~RVD;
-    }
-
     /*
      * Suppress 'C' if next instruction is not aligned
      * TODO: this should check next_pc
@@ -1389,6 +1367,37 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
         return RISCV_EXCP_NONE;
     }
 
+    /*
+     * We'll handle special cases in separate. If one
+     * of these bits are enabled we'll handle them and
+     * end the CSR write.
+     */
+    if (val & RVE && !(env->misa_ext & RVE)) {
+        /*
+         * RVE must be enabled by itself. Clear all other
+         * misa_env bits and let the validation do its
+         * job.
+         */
+        val &= RVE;
+    }
+
+    /*
+     * This flow is similar to what riscv_cpu_realize() does,
+     * with the difference that we will update env->misa_ext
+     * value if everything is ok.
+     */
+    riscv_cpu_validate_misa_ext(env, val, &local_err);
+    if (local_err != NULL) {
+        return RISCV_EXCP_NONE;
+    }
+
+    riscv_cpu_validate_extensions(cpu, val, &local_err);
+    if (local_err != NULL) {
+        return RISCV_EXCP_NONE;
+    }
+
+    riscv_cpu_commit_cpu_cfg(cpu);
+
     if (!(val & RVF)) {
         env->mstatus &= ~MSTATUS_FS;
     }
-- 
2.39.2

[PATCH for-8.1 v3 24/26] target/riscv: update cpu->cfg misa bits in commit_cpu_cfg()

[Daniel Henrique Barboza]

write_misa() is able to use the same validation workflow
riscv_cpu_realize() uses. But it's still not capable of updating
cpu->cfg misa props yet.

We have no way of blocking future (and current) code from checking
env->misa_ext (via riscv_has_ext()) or reading cpu->cfg directly, so our
best alternative is to keep everything in sync.

riscv_cpu_commit_cpu_cfg() now receives an extra 'misa_ext' parameter.
If this val is different from the existing env->misa_ext, update
env->misa and cpu->cfg with the new value. riscv_cpu_realize() will
ignore this code since env->misa_ext isn't touched during validation,
but write_misa() will use it to keep cpu->cfg in sync with the new
env->misa_ext value.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 16 ++++++++++++++--
 target/riscv/cpu.h |  2 +-
 target/riscv/csr.c |  3 +--
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 67a46504bb..2d2a354af3 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1213,8 +1213,20 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
     }
 }
 
-void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu)
+void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext)
 {
+    CPURISCVState *env = &cpu->env;
+
+    /*
+     * write_misa() needs to update cpu->cfg with the new
+     * MISA bits. This is a no-op for the riscv_cpu_realize()
+     * path.
+     */
+    if (env->misa_ext != misa_ext) {
+        env->misa_ext = misa_ext;
+        riscv_set_cpucfg_with_misa(&cpu->cfg, misa_ext);
+    }
+
     if (cpu->cfg.ext_zk) {
         cpu->cfg.ext_zkn = true;
         cpu->cfg.ext_zkr = true;
@@ -1383,7 +1395,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    riscv_cpu_commit_cpu_cfg(cpu);
+    riscv_cpu_commit_cpu_cfg(cpu, env->misa_ext);
 
 #ifndef CONFIG_USER_ONLY
     if (cpu->cfg.ext_sstc) {
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index ca2ba6a647..befc3b8fff 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -597,7 +597,7 @@ void riscv_cpu_validate_misa_ext(CPURISCVState *env, uint32_t misa_ext,
                                  Error **errp);
 void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
                                    Error **errp);
-void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu);
+void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
 
 #define cpu_list riscv_cpu_list
 #define cpu_mmu_index riscv_cpu_mmu_index
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 8d5e8f9ad1..839862f1a8 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1396,7 +1396,7 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
         return RISCV_EXCP_NONE;
     }
 
-    riscv_cpu_commit_cpu_cfg(cpu);
+    riscv_cpu_commit_cpu_cfg(cpu, val);
 
     if (!(val & RVF)) {
         env->mstatus &= ~MSTATUS_FS;
@@ -1404,7 +1404,6 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
 
     /* flush translation cache */
     tb_flush(env_cpu(env));
-    env->misa_ext = val;
     env->xl = riscv_cpu_mxl(env);
     return RISCV_EXCP_NONE;
 }
-- 
2.39.2

[PATCH for-8.1 v3 25/26] target/riscv: allow write_misa() to enable RVG

[Daniel Henrique Barboza]

Allow write_misa() to enable RVG by changing riscv_cpu_enable_g()
slighty: instead of returning void, return the current env->misa_ext
value. This is then retrieved by 'val', which will add the RVG flag
itself, and then we'll skip validation and go right into commiting the
changes.

The reason why it's ok to skip validation in this case is because we're
only allowing RVG (and its associated extensions/Z extensions) to be
enabled in the hart, and riscv_cpu_enable_g() already does its own
validation before enabling itself. Everything else is considered to be
already validated beforehand, so we don't need to repeat ourselves.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c |  7 +++++--
 target/riscv/cpu.h |  2 ++
 target/riscv/csr.c | 15 +++++++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 2d2a354af3..73a5fa46ee 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -281,7 +281,8 @@ static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
     return ext;
 }
 
-static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
+
+target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
 {
     CPURISCVState *env = &cpu->env;
     RISCVCPUConfig *cfg = &cpu->cfg;
@@ -289,7 +290,7 @@ static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
     if (cpu->cfg.ext_zfinx) {
         error_setg(errp, "Unable to enable G: Zfinx is enabled, "
                          "so F can not be enabled");
-        return;
+        return 0;
     }
 
     if (!(cfg->ext_i && cfg->ext_m && cfg->ext_a &&
@@ -315,6 +316,8 @@ static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
         cfg->ext_icsr = true;
         cfg->ext_ifencei = true;
     }
+
+    return env->misa_ext;
 }
 
 static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index befc3b8fff..3ca1d4903c 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -599,6 +599,8 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
                                    Error **errp);
 void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
 
+target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp);
+
 #define cpu_list riscv_cpu_list
 #define cpu_mmu_index riscv_cpu_mmu_index
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 839862f1a8..4335398c19 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1381,6 +1381,20 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
         val &= RVE;
     }
 
+    if (val & RVG && !(env->misa_ext & RVG)) {
+        /*
+         * If the write wants to enable RVG, only RVG and
+         * its dependencies will be updated in the CSR.
+         */
+        val = riscv_cpu_enable_g(cpu, &local_err);
+        if (local_err != NULL) {
+            return RISCV_EXCP_NONE;
+        }
+
+        val |= RVG;
+        goto commit;
+    }
+
     /*
      * This flow is similar to what riscv_cpu_realize() does,
      * with the difference that we will update env->misa_ext
@@ -1396,6 +1410,7 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
         return RISCV_EXCP_NONE;
     }
 
+commit:
     riscv_cpu_commit_cpu_cfg(cpu, val);
 
     if (!(val & RVF)) {
-- 
2.39.2

Re: [PATCH for-8.1 v3 25/26] target/riscv: allow write_misa() to enable RVG

[liweiwei]

On 2023/3/19 04:04, Daniel Henrique Barboza wrote:
> Allow write_misa() to enable RVG by changing riscv_cpu_enable_g()
> slighty: instead of returning void, return the current env->misa_ext
> value. This is then retrieved by 'val', which will add the RVG flag
> itself, and then we'll skip validation and go right into commiting the
> changes.
>
> The reason why it's ok to skip validation in this case is because we're
> only allowing RVG (and its associated extensions/Z extensions) to be
> enabled in the hart, and riscv_cpu_enable_g() already does its own
> validation before enabling itself. Everything else is considered to be
> already validated beforehand, so we don't need to repeat ourselves.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c |  7 +++++--
>   target/riscv/cpu.h |  2 ++
>   target/riscv/csr.c | 15 +++++++++++++++
>   3 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 2d2a354af3..73a5fa46ee 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -281,7 +281,8 @@ static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
>       return ext;
>   }
>   
> -static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
> +
> +target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>   {
>       CPURISCVState *env = &cpu->env;
>       RISCVCPUConfig *cfg = &cpu->cfg;
> @@ -289,7 +290,7 @@ static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>       if (cpu->cfg.ext_zfinx) {
>           error_setg(errp, "Unable to enable G: Zfinx is enabled, "
>                            "so F can not be enabled");
> -        return;
> +        return 0;
>       }
>   
>       if (!(cfg->ext_i && cfg->ext_m && cfg->ext_a &&
> @@ -315,6 +316,8 @@ static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>           cfg->ext_icsr = true;
>           cfg->ext_ifencei = true;
>       }
> +
> +    return env->misa_ext;
>   }
>   
>   static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index befc3b8fff..3ca1d4903c 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -599,6 +599,8 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
>                                      Error **errp);
>   void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
>   
> +target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp);
> +
>   #define cpu_list riscv_cpu_list
>   #define cpu_mmu_index riscv_cpu_mmu_index
>   
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 839862f1a8..4335398c19 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -1381,6 +1381,20 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>           val &= RVE;
>       }
>   
> +    if (val & RVG && !(env->misa_ext & RVG)) {
> +        /*
> +         * If the write wants to enable RVG, only RVG and
> +         * its dependencies will be updated in the CSR.
> +         */
> +        val = riscv_cpu_enable_g(cpu, &local_err);
> +        if (local_err != NULL) {
> +            return RISCV_EXCP_NONE;
> +        }
> +
> +        val |= RVG;

This assignment is not necessary, since RVG is already set in val.

By the way, RVG is still not disabled if any some of included extensions 
are disabled by write_misa.

Regards,

Weiwei Li

> +        goto commit;
> +    }
> +
>       /*
>        * This flow is similar to what riscv_cpu_realize() does,
>        * with the difference that we will update env->misa_ext
> @@ -1396,6 +1410,7 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>           return RISCV_EXCP_NONE;
>       }
>   
> +commit:
>       riscv_cpu_commit_cpu_cfg(cpu, val);
>   
>       if (!(val & RVF)) {

Re: [PATCH for-8.1 v3 25/26] target/riscv: allow write_misa() to enable RVG

[Daniel Henrique Barboza]

On 3/21/23 00:25, liweiwei wrote:
> 
> On 2023/3/19 04:04, Daniel Henrique Barboza wrote:
>> Allow write_misa() to enable RVG by changing riscv_cpu_enable_g()
>> slighty: instead of returning void, return the current env->misa_ext
>> value. This is then retrieved by 'val', which will add the RVG flag
>> itself, and then we'll skip validation and go right into commiting the
>> changes.
>>
>> The reason why it's ok to skip validation in this case is because we're
>> only allowing RVG (and its associated extensions/Z extensions) to be
>> enabled in the hart, and riscv_cpu_enable_g() already does its own
>> validation before enabling itself. Everything else is considered to be
>> already validated beforehand, so we don't need to repeat ourselves.
>>
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   target/riscv/cpu.c |  7 +++++--
>>   target/riscv/cpu.h |  2 ++
>>   target/riscv/csr.c | 15 +++++++++++++++
>>   3 files changed, 22 insertions(+), 2 deletions(-)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index 2d2a354af3..73a5fa46ee 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -281,7 +281,8 @@ static uint32_t riscv_get_misa_ext_with_cpucfg(RISCVCPUConfig *cfg)
>>       return ext;
>>   }
>> -static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>> +
>> +target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>>   {
>>       CPURISCVState *env = &cpu->env;
>>       RISCVCPUConfig *cfg = &cpu->cfg;
>> @@ -289,7 +290,7 @@ static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>>       if (cpu->cfg.ext_zfinx) {
>>           error_setg(errp, "Unable to enable G: Zfinx is enabled, "
>>                            "so F can not be enabled");
>> -        return;
>> +        return 0;
>>       }
>>       if (!(cfg->ext_i && cfg->ext_m && cfg->ext_a &&
>> @@ -315,6 +316,8 @@ static void riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp)
>>           cfg->ext_icsr = true;
>>           cfg->ext_ifencei = true;
>>       }
>> +
>> +    return env->misa_ext;
>>   }
>>   static void riscv_set_cpucfg_with_misa(RISCVCPUConfig *cfg,
>> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
>> index befc3b8fff..3ca1d4903c 100644
>> --- a/target/riscv/cpu.h
>> +++ b/target/riscv/cpu.h
>> @@ -599,6 +599,8 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
>>                                      Error **errp);
>>   void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
>> +target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp);
>> +
>>   #define cpu_list riscv_cpu_list
>>   #define cpu_mmu_index riscv_cpu_mmu_index
>> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
>> index 839862f1a8..4335398c19 100644
>> --- a/target/riscv/csr.c
>> +++ b/target/riscv/csr.c
>> @@ -1381,6 +1381,20 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>>           val &= RVE;
>>       }
>> +    if (val & RVG && !(env->misa_ext & RVG)) {
>> +        /*
>> +         * If the write wants to enable RVG, only RVG and
>> +         * its dependencies will be updated in the CSR.
>> +         */
>> +        val = riscv_cpu_enable_g(cpu, &local_err);
>> +        if (local_err != NULL) {
>> +            return RISCV_EXCP_NONE;
>> +        }
>> +
>> +        val |= RVG;
> 
> This assignment is not necessary, since RVG is already set in val.
> 
> By the way, RVG is still not disabled if any some of included extensions are disabled by write_misa.

I'll include this use case in v4. And I'll also treat RVG as a regular extension since
all checks were already done in realize() time.


Daniel


> 
> Regards,
> 
> Weiwei Li
> 
>> +        goto commit;
>> +    }
>> +
>>       /*
>>        * This flow is similar to what riscv_cpu_realize() does,
>>        * with the difference that we will update env->misa_ext
>> @@ -1396,6 +1410,7 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>>           return RISCV_EXCP_NONE;
>>       }
>> +commit:
>>       riscv_cpu_commit_cpu_cfg(cpu, val);
>>       if (!(val & RVF)) {
> 

[PATCH for-8.1 v3 26/26] target/riscv: allow write_misa() to enable RVV

[Daniel Henrique Barboza]

Allow write_misa() to enable RVV like we did with RVG. We'll need a
riscv_cpu_enable_v() to enable all related misa bits and Z extensions.
This new helper validates the existing 'env' conf by using the existing
riscv_cpu_validate_v(). We'll also check if we'll be able to enable 'F'
by checking for ext_zfinx.

As with RVG, enabling RVV is considered to be a standalone operation in
write_misa(). This means that we'll guarantee that we're not being
inconsistent in riscv_cpu_enable_v() and that we're okay with skipping
regular validation.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 35 +++++++++++++++++++++++++++++++++++
 target/riscv/cpu.h |  1 +
 target/riscv/csr.c | 14 ++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 73a5fa46ee..9c16b29f27 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -983,6 +983,41 @@ static void riscv_cpu_validate_v(CPURISCVState *env,
     env->vext_ver = vext_version;
 }
 
+target_ulong riscv_cpu_enable_v(RISCVCPU *cpu, Error **errp)
+{
+    CPURISCVState *env = &cpu->env;
+    RISCVCPUConfig *cfg = &cpu->cfg;
+    Error *local_err = NULL;
+
+    riscv_cpu_validate_v(env, cfg, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return 0;
+    }
+
+    if (cpu->cfg.ext_zfinx) {
+        error_setg(errp, "Unable to enable V: Zfinx is enabled, "
+                         "so F can not be enabled");
+        return 0;
+    }
+
+    cfg->ext_f = true;
+    env->misa_ext |= RVF;
+
+    cfg->ext_d = true;
+    env->misa_ext |= RVD;
+
+    /*
+     * The V vector extension depends on the
+     *  Zve32f, Zve64f and Zve64d extensions.
+     */
+    cpu->cfg.ext_zve64d = true;
+    cpu->cfg.ext_zve64f = true;
+    cpu->cfg.ext_zve32f = true;
+
+    return env->misa_ext;
+}
+
 static void riscv_cpu_validate_priv_spec(RISCVCPU *cpu, Error **errp)
 {
     CPURISCVState *env = &cpu->env;
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 3ca1d4903c..45e801d926 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -600,6 +600,7 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
 void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
 
 target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp);
+target_ulong riscv_cpu_enable_v(RISCVCPU *cpu, Error **errp);
 
 #define cpu_list riscv_cpu_list
 #define cpu_mmu_index riscv_cpu_mmu_index
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 4335398c19..e9e1afc57e 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1395,6 +1395,20 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
         goto commit;
     }
 
+    if (val & RVV && !(env->misa_ext & RVV)) {
+        /*
+         * If the write wants to enable RVV, only RVV and
+         * its dependencies will be updated in the CSR.
+         */
+        val = riscv_cpu_enable_v(cpu, &local_err);
+        if (local_err != NULL) {
+            return RISCV_EXCP_NONE;
+        }
+
+        val |= RVV;
+        goto commit;
+    }
+
     /*
      * This flow is similar to what riscv_cpu_realize() does,
      * with the difference that we will update env->misa_ext
-- 
2.39.2

Re: [PATCH for-8.1 v3 26/26] target/riscv: allow write_misa() to enable RVV

[liweiwei]

On 2023/3/19 04:04, Daniel Henrique Barboza wrote:
> Allow write_misa() to enable RVV like we did with RVG. We'll need a
> riscv_cpu_enable_v() to enable all related misa bits and Z extensions.
> This new helper validates the existing 'env' conf by using the existing
> riscv_cpu_validate_v(). We'll also check if we'll be able to enable 'F'
> by checking for ext_zfinx.
>
> As with RVG, enabling RVV is considered to be a standalone operation in
> write_misa(). This means that we'll guarantee that we're not being
> inconsistent in riscv_cpu_enable_v() and that we're okay with skipping
> regular validation.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 35 +++++++++++++++++++++++++++++++++++
>   target/riscv/cpu.h |  1 +
>   target/riscv/csr.c | 14 ++++++++++++++
>   3 files changed, 50 insertions(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 73a5fa46ee..9c16b29f27 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -983,6 +983,41 @@ static void riscv_cpu_validate_v(CPURISCVState *env,
>       env->vext_ver = vext_version;
>   }
>   
> +target_ulong riscv_cpu_enable_v(RISCVCPU *cpu, Error **errp)
> +{
> +    CPURISCVState *env = &cpu->env;
> +    RISCVCPUConfig *cfg = &cpu->cfg;
> +    Error *local_err = NULL;
> +
> +    riscv_cpu_validate_v(env, cfg, &local_err);
> +    if (local_err != NULL) {
> +        error_propagate(errp, local_err);
> +        return 0;
> +    }

This check is not necessary, we call this function only when we enable v 
by write_misa, which also have a prerequisite:

V is enabled at the very first. So this check will always be true, since 
the parameter for vector cannot be changed dynamically.

Similar to following check.

> +
> +    if (cpu->cfg.ext_zfinx) {
> +        error_setg(errp, "Unable to enable V: Zfinx is enabled, "
> +                         "so F can not be enabled");
> +        return 0;
> +    }
> +
> +    cfg->ext_f = true;
> +    env->misa_ext |= RVF;
> +
> +    cfg->ext_d = true;
> +    env->misa_ext |= RVD;

We do check V against F/D at first. Why we do this when enable V?

And if we do this,  whether we should also enable F when enable D?


> +
> +    /*
> +     * The V vector extension depends on the
> +     *  Zve32f, Zve64f and Zve64d extensions.
> +     */
> +    cpu->cfg.ext_zve64d = true;
> +    cpu->cfg.ext_zve64f = true;
> +    cpu->cfg.ext_zve32f = true;

This is right, but not necessary in current implementation, since they 
will not be disabled when we disable V.

So we needn't enable them when we re-enable V.

> +
> +    return env->misa_ext;
> +}
> +
>   static void riscv_cpu_validate_priv_spec(RISCVCPU *cpu, Error **errp)
>   {
>       CPURISCVState *env = &cpu->env;
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 3ca1d4903c..45e801d926 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -600,6 +600,7 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
>   void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
>   
>   target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp);
> +target_ulong riscv_cpu_enable_v(RISCVCPU *cpu, Error **errp);
>   
>   #define cpu_list riscv_cpu_list
>   #define cpu_mmu_index riscv_cpu_mmu_index
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 4335398c19..e9e1afc57e 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -1395,6 +1395,20 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>           goto commit;
>       }
>   
> +    if (val & RVV && !(env->misa_ext & RVV)) {
> +        /*
> +         * If the write wants to enable RVV, only RVV and
> +         * its dependencies will be updated in the CSR.
> +         */
> +        val = riscv_cpu_enable_v(cpu, &local_err);
> +        if (local_err != NULL) {
> +            return RISCV_EXCP_NONE;
> +        }
> +
> +        val |= RVV;
> +        goto commit;
> +    }
> +

So, I think we can just treat V as common extension, and do nothing 
additionally for disabling/re-enabling it.

Regards,

Weiwei Li

>       /*
>        * This flow is similar to what riscv_cpu_realize() does,
>        * with the difference that we will update env->misa_ext

Re: [PATCH for-8.1 v3 26/26] target/riscv: allow write_misa() to enable RVV

[Daniel Henrique Barboza]

On 3/21/23 00:41, liweiwei wrote:
> 
> On 2023/3/19 04:04, Daniel Henrique Barboza wrote:
>> Allow write_misa() to enable RVV like we did with RVG. We'll need a
>> riscv_cpu_enable_v() to enable all related misa bits and Z extensions.
>> This new helper validates the existing 'env' conf by using the existing
>> riscv_cpu_validate_v(). We'll also check if we'll be able to enable 'F'
>> by checking for ext_zfinx.
>>
>> As with RVG, enabling RVV is considered to be a standalone operation in
>> write_misa(). This means that we'll guarantee that we're not being
>> inconsistent in riscv_cpu_enable_v() and that we're okay with skipping
>> regular validation.
>>
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   target/riscv/cpu.c | 35 +++++++++++++++++++++++++++++++++++
>>   target/riscv/cpu.h |  1 +
>>   target/riscv/csr.c | 14 ++++++++++++++
>>   3 files changed, 50 insertions(+)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index 73a5fa46ee..9c16b29f27 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -983,6 +983,41 @@ static void riscv_cpu_validate_v(CPURISCVState *env,
>>       env->vext_ver = vext_version;
>>   }
>> +target_ulong riscv_cpu_enable_v(RISCVCPU *cpu, Error **errp)
>> +{
>> +    CPURISCVState *env = &cpu->env;
>> +    RISCVCPUConfig *cfg = &cpu->cfg;
>> +    Error *local_err = NULL;
>> +
>> +    riscv_cpu_validate_v(env, cfg, &local_err);
>> +    if (local_err != NULL) {
>> +        error_propagate(errp, local_err);
>> +        return 0;
>> +    }
> 
> This check is not necessary, we call this function only when we enable v by write_misa, which also have a prerequisite:
> 
> V is enabled at the very first. So this check will always be true, since the parameter for vector cannot be changed dynamically.
> 
> Similar to following check.
> 
>> +
>> +    if (cpu->cfg.ext_zfinx) {
>> +        error_setg(errp, "Unable to enable V: Zfinx is enabled, "
>> +                         "so F can not be enabled");
>> +        return 0;
>> +    }
>> +
>> +    cfg->ext_f = true;
>> +    env->misa_ext |= RVF;
>> +
>> +    cfg->ext_d = true;
>> +    env->misa_ext |= RVD;
> 
> We do check V against F/D at first. Why we do this when enable V?
> 
> And if we do this,  whether we should also enable F when enable D?
> 
> 
>> +
>> +    /*
>> +     * The V vector extension depends on the
>> +     *  Zve32f, Zve64f and Zve64d extensions.
>> +     */
>> +    cpu->cfg.ext_zve64d = true;
>> +    cpu->cfg.ext_zve64f = true;
>> +    cpu->cfg.ext_zve32f = true;
> 
> This is right, but not necessary in current implementation, since they will not be disabled when we disable V.
> 
> So we needn't enable them when we re-enable V.
> 
>> +
>> +    return env->misa_ext;
>> +}
>> +
>>   static void riscv_cpu_validate_priv_spec(RISCVCPU *cpu, Error **errp)
>>   {
>>       CPURISCVState *env = &cpu->env;
>> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
>> index 3ca1d4903c..45e801d926 100644
>> --- a/target/riscv/cpu.h
>> +++ b/target/riscv/cpu.h
>> @@ -600,6 +600,7 @@ void riscv_cpu_validate_extensions(RISCVCPU *cpu, uint32_t misa_ext,
>>   void riscv_cpu_commit_cpu_cfg(RISCVCPU *cpu, uint32_t misa_ext);
>>   target_ulong riscv_cpu_enable_g(RISCVCPU *cpu, Error **errp);
>> +target_ulong riscv_cpu_enable_v(RISCVCPU *cpu, Error **errp);
>>   #define cpu_list riscv_cpu_list
>>   #define cpu_mmu_index riscv_cpu_mmu_index
>> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
>> index 4335398c19..e9e1afc57e 100644
>> --- a/target/riscv/csr.c
>> +++ b/target/riscv/csr.c
>> @@ -1395,6 +1395,20 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
>>           goto commit;
>>       }
>> +    if (val & RVV && !(env->misa_ext & RVV)) {
>> +        /*
>> +         * If the write wants to enable RVV, only RVV and
>> +         * its dependencies will be updated in the CSR.
>> +         */
>> +        val = riscv_cpu_enable_v(cpu, &local_err);
>> +        if (local_err != NULL) {
>> +            return RISCV_EXCP_NONE;
>> +        }
>> +
>> +        val |= RVV;
>> +        goto commit;
>> +    }
>> +
> 
> So, I think we can just treat V as common extension, and do nothing additionally for disabling/re-enabling it.

In fact I think the same can be said about RVG, since both extensions - and in fact,
all extensions - would have to be enabled once during cpu_init() anyway. If not,
env->misa_ext_mask wouldn't allow it be enabled in write_misa() time later on.

I believe I've over-complicated things a bit in these last patches. I'll simplify
things in v4.


Thanks,


Daniel

> 
> Regards,
> 
> Weiwei Li
> 
>>       /*
>>        * This flow is similar to what riscv_cpu_realize() does,
>>        * with the difference that we will update env->misa_ext
>