target/riscv: Add Smrnmi cpu extension

This adds the properties for ISA extension Smrnmi.

Also, when Smrnmi is present, the firmware (e.g., OpenSBI) must set
mnstatus.NMIE to 1 before enabling any interrupts. Otherwise, all
interrupts will be disabled. Since our current OpenSBI does not
support Smrnmi yet, let's disable Smrnmi for the 'max' type CPU for
now. We can re-enable it once OpenSBI includes proper support for it.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250106054336.1878291-6-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 eb06d06628d4ea21fa8904436125690322237a2f..dace670e5e0feece795cec7c843b7249bfe000be 100644 (file)
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -193,6 +193,7 @@ const RISCVIsaExtData isa_edata_arr[] = {
     ISA_EXT_DATA_ENTRY(smaia, PRIV_VERSION_1_12_0, ext_smaia),
     ISA_EXT_DATA_ENTRY(smcntrpmf, PRIV_VERSION_1_12_0, ext_smcntrpmf),
     ISA_EXT_DATA_ENTRY(smepmp, PRIV_VERSION_1_12_0, ext_smepmp),
+    ISA_EXT_DATA_ENTRY(smrnmi, PRIV_VERSION_1_12_0, ext_smrnmi),
     ISA_EXT_DATA_ENTRY(smmpm, PRIV_VERSION_1_13_0, ext_smmpm),
     ISA_EXT_DATA_ENTRY(smnpm, PRIV_VERSION_1_13_0, ext_smnpm),
     ISA_EXT_DATA_ENTRY(smstateen, PRIV_VERSION_1_12_0, ext_smstateen),
@@ -1614,6 +1615,7 @@ const RISCVCPUMultiExtConfig riscv_cpu_extensions[] = {
 
     MULTI_EXT_CFG_BOOL("smaia", ext_smaia, false),
     MULTI_EXT_CFG_BOOL("smepmp", ext_smepmp, false),
+    MULTI_EXT_CFG_BOOL("smrnmi", ext_smrnmi, false),
     MULTI_EXT_CFG_BOOL("smmpm", ext_smmpm, false),
     MULTI_EXT_CFG_BOOL("smnpm", ext_smnpm, false),
     MULTI_EXT_CFG_BOOL("smstateen", ext_smstateen, false),

diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 7f7283d52a9451ec8a6fd7c4a27d4f2edc6c5d40..f94aa9f29e75fa529785d0ce2844fcbb0487c245 100644 (file)
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -1430,6 +1430,15 @@ static void riscv_init_max_cpu_extensions(Object *obj)
     if (env->misa_mxl != MXL_RV32) {
         isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_zcf), false);
     }
+
+    /*
+     * ext_smrnmi requires OpenSBI changes that our current
+     * image does not have. Disable it for now.
+     */
+    if (cpu->cfg.ext_smrnmi) {
+        isa_ext_update_enabled(cpu, CPU_CFG_OFFSET(ext_smrnmi), false);
+        qemu_log("Smrnmi is disabled in the 'max' type CPU\n");
+    }
 }
 
 static bool riscv_cpu_has_max_extensions(Object *cpu_obj)