target/riscv: Add MISA extension implied rules

Add MISA extension implied rules to enable the implied extensions
of MISA recursively.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Jerry Zhang Jian <jerry.zhangjian@sifive.com>
Tested-by: Max Chou <max.chou@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240625114629.27793-4-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 7b071ad..b463bd8 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2250,8 +2250,56 @@
     NULL,
 };
 
+static RISCVCPUImpliedExtsRule RVA_IMPLIED = {
+    .is_misa = true,
+    .ext = RVA,
+    .implied_multi_exts = {
+        CPU_CFG_OFFSET(ext_zalrsc), CPU_CFG_OFFSET(ext_zaamo),
+
+        RISCV_IMPLIED_EXTS_RULE_END
+    },
+};
+
+static RISCVCPUImpliedExtsRule RVD_IMPLIED = {
+    .is_misa = true,
+    .ext = RVD,
+    .implied_misa_exts = RVF,
+    .implied_multi_exts = { RISCV_IMPLIED_EXTS_RULE_END },
+};
+
+static RISCVCPUImpliedExtsRule RVF_IMPLIED = {
+    .is_misa = true,
+    .ext = RVF,
+    .implied_multi_exts = {
+        CPU_CFG_OFFSET(ext_zicsr),
+
+        RISCV_IMPLIED_EXTS_RULE_END
+    },
+};
+
+static RISCVCPUImpliedExtsRule RVM_IMPLIED = {
+    .is_misa = true,
+    .ext = RVM,
+    .implied_multi_exts = {
+        CPU_CFG_OFFSET(ext_zmmul),
+
+        RISCV_IMPLIED_EXTS_RULE_END
+    },
+};
+
+static RISCVCPUImpliedExtsRule RVV_IMPLIED = {
+    .is_misa = true,
+    .ext = RVV,
+    .implied_multi_exts = {
+        CPU_CFG_OFFSET(ext_zve64d),
+
+        RISCV_IMPLIED_EXTS_RULE_END
+    },
+};
+
 RISCVCPUImpliedExtsRule *riscv_misa_ext_implied_rules[] = {
-    NULL
+    &RVA_IMPLIED, &RVD_IMPLIED, &RVF_IMPLIED,
+    &RVM_IMPLIED, &RVV_IMPLIED, NULL
 };
 
 RISCVCPUImpliedExtsRule *riscv_multi_ext_implied_rules[] = {