target/arm: Expand CPUARMState.exception.syndrome to 64 bits

This will be used for storing the ISS2 portion of the
ESR_ELx registers in aarch64 state.  Re-order the fsr
member to eliminate two structure holes.

Drop the comment about "if we implement EL2" since we
have already done so.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20251008215613.300150-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/cpu.h

@@ -633,13 +633,10 @@ typedef struct CPUArchState {
      * entry process.
      */
     struct {
-        uint32_t syndrome; /* AArch64 format syndrome register */
-        uint32_t fsr; /* AArch32 format fault status register info */
+        uint64_t syndrome; /* AArch64 format syndrome register */
         uint64_t vaddress; /* virtual addr associated with exception, if any */
+        uint32_t fsr; /* AArch32 format fault status register info */
         uint32_t target_el; /* EL the exception should be targeted for */
-        /* If we implement EL2 we will also need to store information
-         * about the intermediate physical address for stage 2 faults.
-         */
     } exception;
 
     /* Information associated with an SError */

target/arm/helper.c

@@ -9196,7 +9196,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
                   new_el);
     if (qemu_loglevel_mask(CPU_LOG_INT)
         && !excp_is_internal(cs->exception_index)) {
-        qemu_log_mask(CPU_LOG_INT, "...with ESR 0x%x/0x%" PRIx32 "\n",
+        qemu_log_mask(CPU_LOG_INT, "...with ESR 0x%x/0x%" PRIx64 "\n",
                       syn_get_ec(env->exception.syndrome),
                       env->exception.syndrome);
     }

target/arm/machine.c

@@ -848,6 +848,23 @@ static const VMStateInfo vmstate_powered_off = {
     .put = put_power,
 };
 
+static bool syndrome64_needed(void *opaque)
+{
+    ARMCPU *cpu = opaque;
+    return cpu->env.exception.syndrome > UINT32_MAX;
+}
+
+static const VMStateDescription vmstate_syndrome64 = {
+    .name = "cpu/syndrome64",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = syndrome64_needed,
+    .fields = (const VMStateField[]) {
+        VMSTATE_UINT64(env.exception.syndrome, ARMCPU),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static int cpu_pre_save(void *opaque)
 {
     ARMCPU *cpu = opaque;
@@ -1065,7 +1082,19 @@ const VMStateDescription vmstate_arm_cpu = {
         VMSTATE_UINT64(env.exclusive_val, ARMCPU),
         VMSTATE_UINT64(env.exclusive_high, ARMCPU),
         VMSTATE_UNUSED(sizeof(uint64_t)),
-        VMSTATE_UINT32(env.exception.syndrome, ARMCPU),
+        /*
+         * If any bits are set in the upper 32 bits of syndrome,
+         * then the cpu/syndrome64 subsection will override this
+         * with the full 64 bit state.
+         */
+        {
+            .name = "env.exception.syndrome",
+            .version_id = 0,
+            .size = sizeof(uint32_t),
+            .info = &vmstate_info_uint32,
+            .flags = VMS_SINGLE,
+            .offset = offsetoflow32(ARMCPU, env.exception.syndrome),
+        },
         VMSTATE_UINT32(env.exception.fsr, ARMCPU),
         VMSTATE_UINT64(env.exception.vaddress, ARMCPU),
         VMSTATE_TIMER_PTR(gt_timer[GTIMER_PHYS], ARMCPU),
@@ -1098,6 +1127,7 @@ const VMStateDescription vmstate_arm_cpu = {
         &vmstate_serror,
         &vmstate_irq_line_state,
         &vmstate_wfxt_timer,
+        &vmstate_syndrome64,
         NULL
     }
 };