[RFC PATCH v2 23/32] kvm: introduce KVM_MEMORY_ENCRYPT_OP ioctl

[Brijesh Singh]

If hardware supports encrypting then KVM_MEMORY_ENCRYPT_OP ioctl can
be used by qemu to issue platform specific memory encryption commands.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |    2 ++
 arch/x86/kvm/x86.c              |   12 ++++++++++++
 include/uapi/linux/kvm.h        |    2 ++
 3 files changed, 16 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index bff1f15..62651ad 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1033,6 +1033,8 @@ struct kvm_x86_ops {
 	void (*cancel_hv_timer)(struct kvm_vcpu *vcpu);
 
 	void (*setup_mce)(struct kvm_vcpu *vcpu);
+
+	int (*memory_encryption_op)(struct kvm *kvm, void __user *argp);
 };
 
 struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2099df8..6a737e9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3926,6 +3926,14 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 	return r;
 }
 
+static int kvm_vm_ioctl_memory_encryption_op(struct kvm *kvm, void __user *argp)
+{
+	if (kvm_x86_ops->memory_encryption_op)
+		return kvm_x86_ops->memory_encryption_op(kvm, argp);
+
+	return -ENOTTY;
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
@@ -4189,6 +4197,10 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		r = kvm_vm_ioctl_enable_cap(kvm, &cap);
 		break;
 	}
+	case KVM_MEMORY_ENCRYPT_OP: {
+		r = kvm_vm_ioctl_memory_encryption_op(kvm, argp);
+		break;
+	}
 	default:
 		r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
 	}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index cac48ed..fef7d83 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1281,6 +1281,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_S390_GET_IRQ_STATE	  _IOW(KVMIO, 0xb6, struct kvm_s390_irq_state)
 /* Available with KVM_CAP_X86_SMM */
 #define KVM_SMI                   _IO(KVMIO,   0xb7)
+/* Memory Encryption Commands */
+#define KVM_MEMORY_ENCRYPT_OP	  _IOWR(KVMIO, 0xb8, unsigned long)
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)