KVM: x86: Add missing locking to arch specific vcpu ioctls

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
(cherry picked from commit 8fbf065d)

arch/x86/kvm/x86.c

@@ -1420,6 +1420,7 @@ static int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
 {
 	int r;
 
+	vcpu_load(vcpu);
 	r = -E2BIG;
 	if (cpuid->nent < vcpu->arch.cpuid_nent)
 		goto out;
@@ -1431,6 +1432,7 @@ static int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
 
 out:
 	cpuid->nent = vcpu->arch.cpuid_nent;
+	vcpu_put(vcpu);
 	return r;
 }
 
@@ -1680,6 +1682,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
 	int r;
 	unsigned bank_num = mcg_cap & 0xff, bank;
 
+	vcpu_load(vcpu);
 	r = -EINVAL;
 	if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS)
 		goto out;
@@ -1694,6 +1697,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
 	for (bank = 0; bank < bank_num; bank++)
 		vcpu->arch.mce_banks[bank*4] = ~(u64)0;
 out:
+	vcpu_put(vcpu);
 	return r;
 }
 
@@ -1896,7 +1900,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 		r = -EFAULT;
 		if (copy_from_user(&mce, argp, sizeof mce))
 			goto out;
+		vcpu_load(vcpu);
 		r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
+		vcpu_put(vcpu);
 		break;
 	}
 	default: