[RFC PATCH 14/73] KVM: x86: Create stubs for PVM module as a new vendor

[Lai Jiangshan <jiangshanlai@gmail.com>]

From: Lai Jiangshan <jiangshan.ljs@antgroup.com>

Add a new Kconfig option and create stub files for what will eventually
be a new module named PVM (Pagetable-based PV Virtual Machine). PVM will
function as a vendor module, similar to VMX/SVM for KVM, but it doesn't
require hardware virtualization assistance.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
---
 arch/x86/kvm/Kconfig   |  9 +++++++++
 arch/x86/kvm/Makefile  |  3 +++
 arch/x86/kvm/pvm/pvm.c | 26 ++++++++++++++++++++++++++
 3 files changed, 38 insertions(+)
 create mode 100644 arch/x86/kvm/pvm/pvm.c

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 950c12868d30..49a8b3489a0a 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -118,6 +118,15 @@ config KVM_AMD_SEV
 	  Provides support for launching Encrypted VMs (SEV) and Encrypted VMs
 	  with Encrypted State (SEV-ES) on AMD processors.
 
+config KVM_PVM
+	tristate "Pagetable-based PV Virtual Machine"
+	depends on KVM && X86_64
+	help
+	  Provides Pagetable-based PV Virtual Machine for KVM.
+
+	  To compile this as a module, choose M here: the module
+	  will be called kvm-pvm.
+
 config KVM_SMM
 	bool "System Management Mode emulation"
 	default y
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 97bad203b1b1..036458a27d5e 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -33,9 +33,12 @@ ifdef CONFIG_HYPERV
 kvm-amd-y		+= svm/svm_onhyperv.o
 endif
 
+kvm-pvm-y 		+= pvm/pvm.o
+
 obj-$(CONFIG_KVM)	+= kvm.o
 obj-$(CONFIG_KVM_INTEL)	+= kvm-intel.o
 obj-$(CONFIG_KVM_AMD)	+= kvm-amd.o
+obj-$(CONFIG_KVM_PVM) 	+= kvm-pvm.o
 
 AFLAGS_svm/vmenter.o    := -iquote $(obj)
 $(obj)/svm/vmenter.o: $(obj)/kvm-asm-offsets.h
diff --git a/arch/x86/kvm/pvm/pvm.c b/arch/x86/kvm/pvm/pvm.c
new file mode 100644
index 000000000000..1dfa1ae57c8c
--- /dev/null
+++ b/arch/x86/kvm/pvm/pvm.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Pagetable-based Virtual Machine driver for Linux
+ *
+ * Copyright (C) 2020 Ant Group
+ * Copyright (C) 2020 Alibaba Group
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+#include <linux/module.h>
+
+MODULE_AUTHOR("AntGroup");
+MODULE_LICENSE("GPL");
+
+static void pvm_exit(void)
+{
+}
+module_exit(pvm_exit);
+
+static int __init pvm_init(void)
+{
+	return 0;
+}
+module_init(pvm_init);
-- 
2.19.1.6.gb485710b