[Qemu-devel] [PATCH 3/3] KVM: use KVM_CAP_MAX_VCPU_ID

[Greg Kurz]

As stated in linux/Documentation/virtual/kvm/api.txt:

The maximum possible value for max_vcpu_id can be retrieved using the
KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time.

If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that
max_vcpu_id is the same as the value returned from KVM_CAP_MAX_VCPUS.

Signed-off-by: Greg Kurz <address@hidden>
---
 kvm-all.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kvm-all.c b/kvm-all.c
index e56f38527815..e74e0c6e2352 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1459,10 +1459,16 @@ static int kvm_max_vcpus(KVMState *s)
     return (ret) ? ret : kvm_recommended_vcpus(s);
 }
 
+static int kvm_max_vcpu_id(KVMState *s)
+{
+    int ret = kvm_check_extension(s, KVM_CAP_MAX_VCPU_ID);
+    return (ret) ? ret : kvm_max_vcpus(s);
+}
+
 bool kvm_vcpu_id_is_valid(int vcpu_id)
 {
     KVMState *s = KVM_STATE(current_machine->accelerator);
-    return vcpu_id >= 0 && vcpu_id < kvm_max_vcpus(s);
+    return vcpu_id >= 0 && vcpu_id < kvm_max_vcpu_id(s);
 }
 
 static int kvm_init(MachineState *ms)