target/arm/cpu64: Ensure kvm really supports aarch64=off

If -cpu <cpu>,aarch64=off is used then KVM must also be used, and it
and the host must support running the vcpu in 32-bit mode. Also, if
-cpu <cpu>,aarch64=on is used, then it doesn't matter if kvm is
enabled or not.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index 2a07333c61..98af1050a7 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -208,6 +208,15 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf);
 void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu);
 
 /**
+ * kvm_arm_aarch32_supported:
+ * @cs: CPUState
+ *
+ * Returns: true if the KVM VCPU can enable AArch32 mode
+ * and false otherwise.
+ */
+bool kvm_arm_aarch32_supported(CPUState *cs);
+
+/**
  * kvm_arm_get_max_vm_ipa_size - Returns the number of bits in the
  * IPA address space supported by KVM
  *
@@ -247,6 +256,11 @@ static inline void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
     cpu->host_cpu_probe_failed = true;
 }
 
+static inline bool kvm_arm_aarch32_supported(CPUState *cs)
+{
+    return false;
+}
+
 static inline int kvm_arm_get_max_vm_ipa_size(MachineState *ms)
 {
     return -ENOENT;