[1/24] Move nested option from svm.c to x86.c

Commit Message

Nadav Har'El June 15, 2010, 2:27 p.m. UTC

None

Patch

========
Subject: [PATCH 1/24] Add "nested" module option to vmx.c

This patch adds a module option "nested" to vmx.c, which controls whether
the guest can use VMX instructions, i.e., whether we allow nested
virtualization. A similar, but separate, option already exists for the
SVM module.

This option currently defaults to 0, meaning that nested VMX must be
explicitly enabled by giving nested=1. When nested VMX matures, the default
should probably be changed to enable nested VMX by default - just like
nested SVM is currently enabled by default.

Signed-off-by: Nadav Har'El <[e-mail]>
---
--- .before/arch/x86/kvm/vmx.c	2010-06-15 17:20:01.000000000 +0300
+++ .after/arch/x86/kvm/vmx.c	2010-06-15 17:20:01.000000000 +0300
@@ -67,6 +67,14 @@  module_param(emulate_invalid_guest_state
 static int __read_mostly vmm_exclusive = 1;
 module_param(vmm_exclusive, bool, S_IRUGO);
 
+/*
+ * If nested=1, nested virtualization is supported, i.e., the guest may use
+ * VMX and be a hypervisor for its own guests. If nested=0, the guest may not
+ * use VMX instructions.
+ */
+static int nested = 0;
+module_param(nested, int, S_IRUGO);
+
 #define KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST				\
 	(X86_CR0_WP | X86_CR0_NE | X86_CR0_NW | X86_CR0_CD)
 #define KVM_GUEST_CR0_MASK						\