[PATCH 24/35] target/arm: Handle FEAT_NV2 changes to when SPSR_EL1.M reports EL2

[Peter Maydell]

With FEAT_NV2, the condition for when SPSR_EL1.M should report that
an exception was taken from EL2 changes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 45444360f95..38e16c2f8a5 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11405,10 +11405,18 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs)
         aarch64_save_sp(env, arm_current_el(env));
         env->elr_el[new_el] = env->pc;
 
-        if (cur_el == 1 && new_el == 1 &&
-            ((arm_hcr_el2_eff(env) & (HCR_NV | HCR_NV1)) == HCR_NV)) {
-            /* I_ZJRNN: report EL2 in the SPSR by setting M[3:2] to 0b10 */
-            old_mode = deposit32(old_mode, 2, 2, 2);
+        if (cur_el == 1 && new_el == 1) {
+            uint64_t hcr = arm_hcr_el2_eff(env);
+            if ((hcr & (HCR_NV | HCR_NV1 | HCR_NV2)) == HCR_NV ||
+                (hcr & (HCR_NV | HCR_NV2)) == (HCR_NV | HCR_NV2)) {
+                /*
+                 * FEAT_NV, FEAT_NV2 may need to report EL2 in the SPSR
+                 * by setting M[3:2] to 0b10.
+                 * If NV2 is disabled, change SPSR when NV,NV1 == 1,0 (I_ZJRNN)
+                 * If NV2 is enabled, change SPSR when NV is 1 (I_DBTLM)
+                 */
+                old_mode = deposit32(old_mode, 2, 2, 2);
+            }
         }
     } else {
         old_mode = cpsr_read_for_spsr_elx(env);
-- 
2.34.1