target-arm: kvm: save/restore mp state

This adds the saving and restore of the current Multi-Processing state
of the machine. While the KVM_GET/SET_MP_STATE API exposes a number of
potential states for x86 we only use two for ARM. Either the process is
running or not. We then save this state into the cpu_powered TCG state
to avoid changing the serialisation format.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index 72c1fa1e64..fdd9ba3f1d 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -28,6 +28,8 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
 };
 
+static bool cap_has_mp_state;
+
 int kvm_arm_vcpu_init(CPUState *cs)
 {
     ARMCPU *cpu = ARM_CPU(cs);
@@ -157,6 +159,8 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
      */
     kvm_async_interrupts_allowed = true;
 
+    cap_has_mp_state = kvm_check_extension(s, KVM_CAP_MP_STATE);
+
     type_register_static(&host_arm_cpu_type_info);
 
     return 0;
@@ -458,6 +462,46 @@ void kvm_arm_reset_vcpu(ARMCPU *cpu)
     }
 }
 
+/*
+ * Update KVM's MP_STATE based on what QEMU thinks it is
+ */
+int kvm_arm_sync_mpstate_to_kvm(ARMCPU *cpu)
+{
+    if (cap_has_mp_state) {
+        struct kvm_mp_state mp_state = {
+            .mp_state =
+            cpu->powered_off ? KVM_MP_STATE_STOPPED : KVM_MP_STATE_RUNNABLE
+        };
+        int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MP_STATE, &mp_state);
+        if (ret) {
+            fprintf(stderr, "%s: failed to set MP_STATE %d/%s\n",
+                    __func__, ret, strerror(-ret));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * Sync the KVM MP_STATE into QEMU
+ */
+int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu)
+{
+    if (cap_has_mp_state) {
+        struct kvm_mp_state mp_state;
+        int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MP_STATE, &mp_state);
+        if (ret) {
+            fprintf(stderr, "%s: failed to get MP_STATE %d/%s\n",
+                    __func__, ret, strerror(-ret));
+            abort();
+        }
+        cpu->powered_off = (mp_state.mp_state == KVM_MP_STATE_STOPPED);
+    }
+
+    return 0;
+}
+
 void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run)
 {
 }