[PATCH 2/4] target/riscv: Add CPU feature for AIA CSRs

[Anup Patel <anup.patel@wdc.com>]

We add experimental CPU feature to enable AIA CSRs. This experimental
feature can be enabled by setting "x-aia=true" for CPU in the QEMU
command-line parameters.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 target/riscv/cpu.c | 5 +++++
 target/riscv/cpu.h | 4 +++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 7d6ed80f6b..f3702111ae 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -414,6 +414,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         set_feature(env, RISCV_FEATURE_PMP);
     }
 
+    if (cpu->cfg.aia) {
+        set_feature(env, RISCV_FEATURE_AIA);
+    }
+
     set_resetvec(env, cpu->cfg.resetvec);
 
     /* If only XLEN is set for misa, then set misa from properties */
@@ -554,6 +558,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
+    DEFINE_PROP_BOOL("x-aia", RISCVCPU, cfg.aia, false),
     DEFINE_PROP_UINT64("resetvec", RISCVCPU, cfg.resetvec, DEFAULT_RSTVEC),
     DEFINE_PROP_END_OF_LIST(),
 };
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0a33d387ba..f00c60c840 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -80,7 +80,8 @@
 enum {
     RISCV_FEATURE_MMU,
     RISCV_FEATURE_PMP,
-    RISCV_FEATURE_MISA
+    RISCV_FEATURE_MISA,
+    RISCV_FEATURE_AIA
 };
 
 #define PRIV_VERSION_1_10_0 0x00011000
@@ -303,6 +304,7 @@ struct RISCVCPU {
         uint16_t elen;
         bool mmu;
         bool pmp;
+        bool aia;
         uint64_t resetvec;
     } cfg;
 };
-- 
2.25.1