target/riscv: Implement checks for hfence

Call the helper_hyp_tlb_flush() function on hfence instructions which
will generate an illegal insruction execption if we don't have
permission to flush the Hypervisor level TLBs.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index b0c49efc4a..7cccd42a1e 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -194,4 +194,17 @@ void helper_tlb_flush(CPURISCVState *env)
     }
 }
 
+void helper_hyp_tlb_flush(CPURISCVState *env)
+{
+    CPUState *cs = env_cpu(env);
+
+    if (env->priv == PRV_M ||
+        (env->priv == PRV_S && !riscv_cpu_virt_enabled(env))) {
+        tlb_flush(cs);
+        return;
+    }
+
+    riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
+}
+
 #endif /* !CONFIG_USER_ONLY */