[Qemu-devel] [PATCH v2 1/3] target/s390x: Indicate and check for local tlb clearing

[David Hildenbrand <david@redhat.com>]

Let's allow to enable it for the qemu cpu model and correctly emulate
it.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/cpu_models.c | 1 +
 target/s390x/mem_helper.c | 2 --
 target/s390x/translate.c  | 6 +++++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index 478bcc6..8fce957 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -685,6 +685,7 @@ static void add_qemu_cpu_model_features(S390FeatBitmap fbm)
         S390_FEAT_GENERAL_INSTRUCTIONS_EXT,
         S390_FEAT_EXECUTE_EXT,
         S390_FEAT_STFLE_45,
+        S390_FEAT_LOCAL_TLB_CLEARING,
     };
     int i;
 
diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 80caab9..41e5a1d 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -1558,8 +1558,6 @@ void HELPER(ipte)(CPUS390XState *env, uint64_t pto, uint64_t vaddr,
 
     /* XXX we exploit the fact that Linux passes the exact virtual
        address here - it's not obliged to! */
-    /* XXX: the LC bit should be considered as 0 if the local-TLB-clearing
-       facility is not installed.  */
     if (m4 & 1) {
         tlb_flush_page(cs, page);
     } else {
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index 8c055b7..7efc10b 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -2412,7 +2412,11 @@ static ExitStatus op_ipte(DisasContext *s, DisasOps *o)
     TCGv_i32 m4;
 
     check_privileged(s);
-    m4 = tcg_const_i32(get_field(s->fields, m4));
+    if (s390_has_feat(S390_FEAT_LOCAL_TLB_CLEARING)) {
+        m4 = tcg_const_i32(get_field(s->fields, m4));
+    } else {
+        m4 = tcg_const_i32(0);
+    }
     gen_helper_ipte(cpu_env, o->in1, o->in2, m4);
     tcg_temp_free_i32(m4);
     return NO_EXIT;
-- 
2.9.4