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, 23 insertions, 0 deletions

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 4e19191ed5..87a899d638 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -6239,6 +6239,29 @@ static bool trans_WFI(DisasContext *s, arg_WFI *a)
     return true;
 }
 
+static bool trans_ESB(DisasContext *s, arg_ESB *a)
+{
+    /*
+     * For M-profile, minimal-RAS ESB can be a NOP.
+     * Without RAS, we must implement this as NOP.
+     */
+    if (!arm_dc_feature(s, ARM_FEATURE_M) && dc_isar_feature(aa32_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
+         *      AArch32.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);
+        }
+    }
+    return true;
+}
+
 static bool trans_NOP(DisasContext *s, arg_NOP *a)
 {
     return true;