[RFC PATCH 05/16] target/riscv: Add CPU options of WorldGuard CPU extension

[Jim Shu]

We define CPU options for WG CSR support in RISC-V CPUs which
can be set by machine/device emulation. The RISC-V CSR emulation
will also check this feature for emulating WG CSRs.

Signed-off-by: Jim Shu <jim....@sifive.com>
---
 target/riscv/cpu.c         |  8 ++++++++
 target/riscv/cpu_cfg.h     |  3 +++
 target/riscv/tcg/tcg-cpu.c | 11 +++++++++++
 3 files changed, 22 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 69a08e8c2c..d70eedf957 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -204,6 +204,9 @@ const RISCVIsaExtData isa_edata_arr[] = {
     ISA_EXT_DATA_ENTRY(xtheadmempair, PRIV_VERSION_1_11_0, ext_xtheadmempair),
     ISA_EXT_DATA_ENTRY(xtheadsync, PRIV_VERSION_1_11_0, ext_xtheadsync),
     ISA_EXT_DATA_ENTRY(xventanacondops, PRIV_VERSION_1_12_0, 
ext_XVentanaCondOps),
+    ISA_EXT_DATA_ENTRY(smwg, PRIV_VERSION_1_12_0, ext_smwg),
+    ISA_EXT_DATA_ENTRY(smwgd, PRIV_VERSION_1_12_0, ext_smwgd),
+    ISA_EXT_DATA_ENTRY(sswg, PRIV_VERSION_1_12_0, ext_sswg),
 
     DEFINE_PROP_END_OF_LIST(),
 };
@@ -1595,6 +1598,11 @@ const RISCVCPUMultiExtConfig 
riscv_cpu_experimental_exts[] = {
 const RISCVCPUMultiExtConfig riscv_cpu_named_features[] = {
     MULTI_EXT_CFG_BOOL("zic64b", ext_zic64b, true),
 
+    /* RISC-V WorldGuard v0.4 */
+    MULTI_EXT_CFG_BOOL("x-smwg", ext_smwg, false),
+    MULTI_EXT_CFG_BOOL("x-smwgd", ext_smwgd, false),
+    MULTI_EXT_CFG_BOOL("x-sswg", ext_sswg, false),
+
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h
index e1e4f32698..23e779ae08 100644
--- a/target/riscv/cpu_cfg.h
+++ b/target/riscv/cpu_cfg.h
@@ -120,6 +120,9 @@ struct RISCVCPUConfig {
     bool ext_ssaia;
     bool ext_sscofpmf;
     bool ext_smepmp;
+    bool ext_smwg;
+    bool ext_smwgd;
+    bool ext_sswg;
     bool rvv_ta_all_1s;
     bool rvv_ma_all_1s;
 
diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 683f604d9f..dc86e6e1d5 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -726,6 +726,17 @@ void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, 
Error **errp)
         cpu->pmu_avail_ctrs = 0;
     }
 
+    /* RISC-V WorldGuard */
+    if (cpu->cfg.ext_sswg && !cpu->cfg.ext_smwg) {
+        error_setg(errp, "Sswg extension requires Smwg extension");
+        return;
+    }
+
+    if (cpu->cfg.ext_smwgd != cpu->cfg.ext_sswg) {
+        error_setg(errp, "Smwgd/Sswg extensions should be enabled together");
+        return;
+    }
+
     /*
      * Disable isa extensions based on priv spec after we
      * validated and set everything we need.
-- 
2.17.1