KVM: SVM: Allow setting the SVME bit
Normally setting the SVME bit in EFER is not allowed, as we did
not support SVM. Not since we do, we should also allow enabling
SVM mode.
v2 comes as last patch, so we don't enable half-ready code
v4 introduces a module option to enable SVM
v6 warns that nesting is enabled
Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index df5b411..0fbbde5 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -69,6 +69,9 @@
module_param(npt, int, S_IRUGO);
+static int nested = 0;
+module_param(nested, int, S_IRUGO);
+
static void kvm_reput_irq(struct vcpu_svm *svm);
static void svm_flush_tlb(struct kvm_vcpu *vcpu);
@@ -443,6 +446,11 @@
if (boot_cpu_has(X86_FEATURE_NX))
kvm_enable_efer_bits(EFER_NX);
+ if (nested) {
+ printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
+ kvm_enable_efer_bits(EFER_SVME);
+ }
+
for_each_online_cpu(cpu) {
r = svm_cpu_init(cpu);
if (r)
