target/riscv: Extend pc for runtime pc write

In some cases, we must restore the guest PC to the address of the start of
the TB, such as when the instruction counter hits zero. So extend pc register
according to current xlen for these cases.

Signed-off-by: LIU Zhiwei <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: 20220120122050[email protected]
Signed-off-by: Alistair Francis <[email protected]>

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 736cf1d4e75571cca218ca3cd9f17fb2f83d6479..eac5f7bf034bcbcb40de5a9639c5ca6afe8fdef9 100644 (file)
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -355,7 +355,12 @@ static void riscv_cpu_set_pc(CPUState *cs, vaddr value)
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
-    env->pc = value;
+
+    if (env->xl == MXL_RV32) {
+        env->pc = (int32_t)value;
+    } else {
+        env->pc = value;
+    }
 }
 
 static void riscv_cpu_synchronize_from_tb(CPUState *cs,
@@ -363,7 +368,13 @@ static void riscv_cpu_synchronize_from_tb(CPUState *cs,
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
-    env->pc = tb->pc;
+    RISCVMXL xl = FIELD_EX32(tb->flags, TB_FLAGS, XL);
+
+    if (xl == MXL_RV32) {
+        env->pc = (int32_t)tb->pc;
+    } else {
+        env->pc = tb->pc;
+    }
 }
 
 static bool riscv_cpu_has_work(CPUState *cs)
@@ -384,7 +395,12 @@ static bool riscv_cpu_has_work(CPUState *cs)
 void restore_state_to_opc(CPURISCVState *env, TranslationBlock *tb,
                           target_ulong *data)
 {
-    env->pc = data[0];
+    RISCVMXL xl = FIELD_EX32(tb->flags, TB_FLAGS, XL);
+    if (xl == MXL_RV32) {
+        env->pc = (int32_t)data[0];
+    } else {
+        env->pc = data[0];
+    }
 }
 
 static void riscv_cpu_reset(DeviceState *dev)