diff mbox series

[RESEND,v8,19/20] target/riscv/cpu.c: honor user choice in cpu_cfg_ext_auto_update()

Message ID 20230824221440.484675-20-dbarboza@ventanamicro.com
State New
Headers show
Series riscv: 'max' CPU, detect user choice in TCG | expand

Commit Message

Daniel Henrique Barboza Aug. 24, 2023, 10:14 p.m. UTC 
Add a new cpu_cfg_ext_is_user_set() helper to check if an extension was
set by the user in the command line. Use it inside
cpu_cfg_ext_auto_update() to verify if the user set a certain extension
and, if that's the case, do not change its value.

This will make us honor user choice instead of overwriting the values.
Users will then be informed whether they're using an incompatible set of
extensions instead of QEMU setting a magic value that works.

For example, we'll now error out if the user explictly set 'zce' to true
and 'zca' to false:

$ ./build/qemu-system-riscv64 -M virt -cpu rv64,zce=true,zca=false -nographic
qemu-system-riscv64: Zcf/Zcd/Zcb/Zcmp/Zcmt extensions require Zca extension

This didn't happen before because we were enabling 'zca' if 'zce' was enabled
regardless if the user explictly set 'zca' to false.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Andrew Jones Aug. 31, 2023, 1:58 p.m. UTC | #1 
On Thu, Aug 24, 2023 at 07:14:39PM -0300, Daniel Henrique Barboza wrote:
> Add a new cpu_cfg_ext_is_user_set() helper to check if an extension was
> set by the user in the command line. Use it inside
> cpu_cfg_ext_auto_update() to verify if the user set a certain extension
> and, if that's the case, do not change its value.
> 
> This will make us honor user choice instead of overwriting the values.
> Users will then be informed whether they're using an incompatible set of
> extensions instead of QEMU setting a magic value that works.
> 
> For example, we'll now error out if the user explictly set 'zce' to true
> and 'zca' to false:
> 
> $ ./build/qemu-system-riscv64 -M virt -cpu rv64,zce=true,zca=false -nographic
> qemu-system-riscv64: Zcf/Zcd/Zcb/Zcmp/Zcmt extensions require Zca extension
> 
> This didn't happen before because we were enabling 'zca' if 'zce' was enabled
> regardless if the user explictly set 'zca' to false.
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index ae8c35402f..e07b2c73e7 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -196,6 +196,12 @@ static int cpu_cfg_ext_get_min_version(uint32_t ext_offset)
>      return PRIV_VERSION_1_10_0;
>  }
>  
> +static bool cpu_cfg_ext_is_user_set(uint32_t ext_offset)
> +{
> +    return g_hash_table_contains(multi_ext_user_opts,
> +                                 GUINT_TO_POINTER(ext_offset));
> +}
> +
>  static void cpu_cfg_ext_auto_update(RISCVCPU *cpu, uint32_t ext_offset,
>                                      bool value)
>  {
> @@ -207,6 +213,10 @@ static void cpu_cfg_ext_auto_update(RISCVCPU *cpu, uint32_t ext_offset,
>          return;
>      }
>  
> +    if (cpu_cfg_ext_is_user_set(ext_offset)) {
> +        return;
> +    }
> +
>      if (value && env->priv_ver != PRIV_VERSION_LATEST) {
>          /* Do not enable it if priv_ver is older than min_version */
>          min_version = cpu_cfg_ext_get_min_version(ext_offset);
> -- 
> 2.41.0
> 
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
diff mbox series

Patch

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index ae8c35402f..e07b2c73e7 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -196,6 +196,12 @@  static int cpu_cfg_ext_get_min_version(uint32_t ext_offset)
     return PRIV_VERSION_1_10_0;
 }
 
+static bool cpu_cfg_ext_is_user_set(uint32_t ext_offset)
+{
+    return g_hash_table_contains(multi_ext_user_opts,
+                                 GUINT_TO_POINTER(ext_offset));
+}
+
 static void cpu_cfg_ext_auto_update(RISCVCPU *cpu, uint32_t ext_offset,
                                     bool value)
 {
@@ -207,6 +213,10 @@  static void cpu_cfg_ext_auto_update(RISCVCPU *cpu, uint32_t ext_offset,
         return;
     }
 
+    if (cpu_cfg_ext_is_user_set(ext_offset)) {
+        return;
+    }
+
     if (value && env->priv_ver != PRIV_VERSION_LATEST) {
         /* Do not enable it if priv_ver is older than min_version */
         min_version = cpu_cfg_ext_get_min_version(ext_offset);