[PATCH v5 04/16] KVM: x86/xen: add KVM_XEN_HVM_SET_ATTR/KVM_XEN_HVM_GET_ATTR

[David Woodhouse <dwmw2@xxxxxxxxxxxxx>]

From: Joao Martins <joao.m.martins@xxxxxxxxxx>

This will be used to set up shared info pages etc.

Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
 arch/x86/kvm/x86.c       | 20 ++++++++++++++++++++
 arch/x86/kvm/xen.c       | 24 ++++++++++++++++++++++++
 arch/x86/kvm/xen.h       |  2 ++
 include/uapi/linux/kvm.h | 11 +++++++++++
 4 files changed, 57 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4e6b8c4d7824..fd0a4ff1157e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5618,6 +5618,26 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		r = 0;
 		break;
 	}
+	case KVM_XEN_HVM_GET_ATTR: {
+		struct kvm_xen_hvm_attr xha;
+
+		r = -EFAULT;
+		if (copy_from_user(&xha, argp, sizeof(xha)))
+			goto out;
+		r = kvm_xen_hvm_get_attr(kvm, &xha);
+		if (!r && copy_to_user(argp, &xha, sizeof(xha)))
+			r = -EFAULT;
+		break;
+	}
+	case KVM_XEN_HVM_SET_ATTR: {
+		struct kvm_xen_hvm_attr xha;
+
+		r = -EFAULT;
+		if (copy_from_user(&xha, argp, sizeof(xha)))
+			goto out;
+		r = kvm_xen_hvm_set_attr(kvm, &xha);
+		break;
+	}
 	case KVM_SET_CLOCK: {
 		struct kvm_clock_data user_ns;
 		u64 now_ns;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 503935d8212e..c0b2c67e0235 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -16,6 +16,30 @@
 
 #include "trace.h"
 
+int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
+{
+	int r = -ENOENT;
+
+	switch (data->type) {
+	default:
+		break;
+	}
+
+	return r;
+}
+
+int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
+{
+	int r = -ENOENT;
+
+	switch (data->type) {
+	default:
+		break;
+	}
+
+	return r;
+}
+
 int kvm_xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
 {
 	struct kvm *kvm = vcpu->kvm;
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index 81e12f716d2e..d06b5afcc1f2 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -9,6 +9,8 @@
 #ifndef __ARCH_X86_KVM_XEN_H__
 #define __ARCH_X86_KVM_XEN_H__
 
+int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data);
+int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data);
 int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
 int kvm_xen_hvm_config(struct kvm_vcpu *vcpu, u64 data);
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9eee81bcd0e0..31d4eb100efd 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1585,6 +1585,17 @@ struct kvm_pv_cmd {
 /* Available with KVM_CAP_DIRTY_LOG_RING */
 #define KVM_RESET_DIRTY_RINGS		_IO(KVMIO, 0xc7)
 
+#define KVM_XEN_HVM_GET_ATTR	_IOWR(KVMIO, 0xc8, struct kvm_xen_hvm_attr)
+#define KVM_XEN_HVM_SET_ATTR	_IOW(KVMIO,  0xc9, struct kvm_xen_hvm_attr)
+
+struct kvm_xen_hvm_attr {
+	__u16 type;
+	__u16 pad[3];
+	union {
+		__u64 pad[4];
+	} u;
+};
+
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {
 	/* Guest initialization commands */
-- 
2.29.2