KVM: Make the supported cpuid list a host property rather than a vm property

One of the use cases for the supported cpuid list is to create a "greatest
common denominator" of cpu capabilities in a server farm.  As such, it is
useful to be able to get the list without creating a virtual machine first.

Since the code does not depend on the vm in any way, all that is needed is
to move it to the device ioctl handler.  The capability identifier is also
changed so that binaries made against -rc1 will fail gracefully.

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 22 insertions, 20 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ec60409299a..a7069ec2267 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -46,6 +46,9 @@
 #define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
 #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
 
+static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
+				    struct kvm_cpuid_entry2 __user *entries);
+
 struct kvm_x86_ops *kvm_x86_ops;
 
 struct kvm_stats_debugfs_item debugfs_entries[] = {
@@ -727,6 +730,24 @@ long kvm_arch_dev_ioctl(struct file *filp,
 		r = 0;
 		break;
 	}
+	case KVM_GET_SUPPORTED_CPUID: {
+		struct kvm_cpuid2 __user *cpuid_arg = argp;
+		struct kvm_cpuid2 cpuid;
+
+		r = -EFAULT;
+		if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
+			goto out;
+		r = kvm_dev_ioctl_get_supported_cpuid(&cpuid,
+			cpuid_arg->entries);
+		if (r)
+			goto out;
+
+		r = -EFAULT;
+		if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
+			goto out;
+		r = 0;
+		break;
+	}
 	default:
 		r = -EINVAL;
 	}
@@ -974,8 +995,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 	put_cpu();
 }
 
-static int kvm_vm_ioctl_get_supported_cpuid(struct kvm *kvm,
-				    struct kvm_cpuid2 *cpuid,
+static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
 				    struct kvm_cpuid_entry2 __user *entries)
 {
 	struct kvm_cpuid_entry2 *cpuid_entries;
@@ -1487,24 +1507,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		r = 0;
 		break;
 	}
-	case KVM_GET_SUPPORTED_CPUID: {
-		struct kvm_cpuid2 __user *cpuid_arg = argp;
-		struct kvm_cpuid2 cpuid;
-
-		r = -EFAULT;
-		if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
-			goto out;
-		r = kvm_vm_ioctl_get_supported_cpuid(kvm, &cpuid,
-			cpuid_arg->entries);
-		if (r)
-			goto out;
-
-		r = -EFAULT;
-		if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
-			goto out;
-		r = 0;
-		break;
-	}
 	default:
 		;
 	}