target/arm: Implement ESB instruction

Check for and defer any pending virtual SError.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index b803136..5a02e07 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -1454,6 +1454,23 @@ static void handle_hint(DisasContext *s, uint32_t insn,
             gen_helper_autib(cpu_X[17], cpu_env, cpu_X[17], cpu_X[16]);
         }
         break;
+    case 0b10000: /* ESB */
+        /* Without RAS, we must implement this as NOP. */
+        if (dc_isar_feature(aa64_ras, s)) {
+            /*
+             * QEMU does not have a source of physical SErrors,
+             * so we are only concerned with virtual SErrors.
+             * The pseudocode in the ARM for this case is
+             *   if PSTATE.EL IN {EL0, EL1} && EL2Enabled() then
+             *      AArch64.vESBOperation();
+             * Most of the condition can be evaluated at translation time.
+             * Test for EL2 present, and defer test for SEL2 to runtime.
+             */
+            if (s->current_el <= 1 && arm_dc_feature(s, ARM_FEATURE_EL2)) {
+                gen_helper_vesb(cpu_env);
+            }
+        }
+        break;
     case 0b11000: /* PACIAZ */
         if (s->pauth_active) {
             gen_helper_pacia(cpu_X[30], cpu_env, cpu_X[30],