[PATCH v6 16/45] target/arm: Handle SME in sve_access_check

[Richard Henderson <richard.henderson@linaro.org>]

The pseudocode for CheckSVEEnabled gains a check for Streaming
SVE mode, and for SME present but SVE absent.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index b16d81bf19..b7b64f7358 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -1183,21 +1183,31 @@ static bool fp_access_check(DisasContext *s)
     return true;
 }
 
-/* Check that SVE access is enabled.  If it is, return true.
+/*
+ * Check that SVE access is enabled.  If it is, return true.
  * If not, emit code to generate an appropriate exception and return false.
+ * This function corresponds to CheckSVEEnabled().
  */
 bool sve_access_check(DisasContext *s)
 {
-    if (s->sve_excp_el) {
-        assert(!s->sve_access_checked);
-        s->sve_access_checked = true;
-
+    if (s->pstate_sm || !dc_isar_feature(aa64_sve, s)) {
+        assert(dc_isar_feature(aa64_sme, s));
+        if (!sme_sm_enabled_check(s)) {
+            goto fail_exit;
+        }
+    } else if (s->sve_excp_el) {
         gen_exception_insn_el(s, s->pc_curr, EXCP_UDEF,
                               syn_sve_access_trap(), s->sve_excp_el);
-        return false;
+        goto fail_exit;
     }
     s->sve_access_checked = true;
     return fp_access_check(s);
+
+ fail_exit:
+    /* Assert that we only raise one exception per instruction. */
+    assert(!s->sve_access_checked);
+    s->sve_access_checked = true;
+    return false;
 }
 
 /*
-- 
2.34.1