target-arm: add powered off cpu state

Add tracking of cpu power state in order to support powering off of
cores in system emuluation. The initial state is determined by the
start-powered-off QOM property.
Signed-off-by: NRob Herring <rob.herring@linaro.org>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1412865028-17725-2-git-send-email-peter.maydell@linaro.org

target-arm/cpu-qom.h

@@ -98,6 +98,8 @@ typedef struct ARMCPU {
 
     /* Should CPU start in PSCI powered-off state? */
     bool start_powered_off;
+    /* CPU currently in PSCI powered-off state */
+    bool powered_off;
 
     /* [QEMU_]KVM_ARM_TARGET_* constant for this CPU, or
      * QEMU_KVM_ARM_TARGET_NONE if the kernel doesn't support this CPU type.

target-arm/cpu.c

@@ -40,7 +40,10 @@ static void arm_cpu_set_pc(CPUState *cs, vaddr value)
 
 static bool arm_cpu_has_work(CPUState *cs)
 {
-    return cs->interrupt_request &
+    ARMCPU *cpu = ARM_CPU(cs);
+
+    return !cpu->powered_off
+        && cs->interrupt_request &
         (CPU_INTERRUPT_FIQ | CPU_INTERRUPT_HARD
          | CPU_INTERRUPT_VFIQ | CPU_INTERRUPT_VIRQ
          | CPU_INTERRUPT_EXITTB);
@@ -93,6 +96,9 @@ static void arm_cpu_reset(CPUState *s)
     env->vfp.xregs[ARM_VFP_MVFR1] = cpu->mvfr1;
     env->vfp.xregs[ARM_VFP_MVFR2] = cpu->mvfr2;
 
+    cpu->powered_off = cpu->start_powered_off;
+    s->halted = cpu->start_powered_off;
+
     if (arm_feature(env, ARM_FEATURE_IWMMXT)) {
         env->iwmmxt.cregs[ARM_IWMMXT_wCID] = 0x69051000 | 'Q';
     }

target-arm/machine.c

@@ -222,8 +222,8 @@ static int cpu_post_load(void *opaque, int version_id)
 
 const VMStateDescription vmstate_arm_cpu = {
     .name = "cpu",
-    .version_id = 20,
-    .minimum_version_id = 20,
+    .version_id = 21,
+    .minimum_version_id = 21,
     .pre_save = cpu_pre_save,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
@@ -263,6 +263,7 @@ const VMStateDescription vmstate_arm_cpu = {
         VMSTATE_UINT64(env.exception.vaddress, ARMCPU),
         VMSTATE_TIMER(gt_timer[GTIMER_PHYS], ARMCPU),
         VMSTATE_TIMER(gt_timer[GTIMER_VIRT], ARMCPU),
+        VMSTATE_BOOL(powered_off, ARMCPU),
         VMSTATE_END_OF_LIST()
     },
     .subsections = (VMStateSubsection[]) {