[Qemu-devel] [PATCH v2] target-xtensa: raise an exception for invalid and reserved opcodes

[Max Filippov <jcmvbkbc@gmail.com>]

This includes opcodes from disabled features and those marked reserved in the ISA.
Also end TB on opcodes that definitely generate an exception: illegal
instructions, syscall and privileged instructions.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
v1 -> v2 changes:
- end TB on opcodes that definitely generate an exception.
---
 target-xtensa/translate.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index 1688bb2..c20c9cc 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -266,6 +266,10 @@ static void gen_exception_cause(DisasContext *dc, uint32_t cause)
     gen_helper_exception_cause(tpc, tcause);
     tcg_temp_free(tpc);
     tcg_temp_free(tcause);
+    if (cause == ILLEGAL_INSTRUCTION_CAUSE ||
+            cause == SYSCALL_CAUSE) {
+        dc->is_jmp = DISAS_UPDATE;
+    }
 }
 
 static void gen_exception_cause_vaddr(DisasContext *dc, uint32_t cause,
@@ -283,6 +287,7 @@ static void gen_check_privilege(DisasContext *dc)
 {
     if (dc->cring) {
         gen_exception_cause(dc, PRIVILEGED_CAUSE);
+        dc->is_jmp = DISAS_UPDATE;
     }
 }
 
@@ -2378,7 +2383,7 @@ static void disas_xtensa_insn(DisasContext *dc)
 
 invalid_opcode:
     qemu_log("INVALID(pc = %08x)\n", dc->pc);
-    dc->pc = dc->next_pc;
+    gen_exception_cause(dc, ILLEGAL_INSTRUCTION_CAUSE);
 #undef HAS_OPTION
 }
 
-- 
1.7.6.4