KVM: SVM: document KVM_MEM_ENCRYPT_OP, let userspace detect if SEV is available

[linux-2.6-microblaze.git] / arch / x86 / kvm / svm.c

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 9100050..f0aa9ff 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7158,6 +7158,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
        if (!svm_sev_enabled())
                return -ENOTTY;
 
+       if (!argp)
+               return 0;
+
        if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
                return -EFAULT;