From 1e58e5e59148916fa43444a406335a990783fb78 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 17 Oct 2018 00:55:22 +0200 Subject: KVM: VMX: enable nested virtualization by default With live migration support and finally a good solution for exception event injection, nested VMX should be ready for having a stable userspace ABI. The results of syzkaller fuzzing are not perfect but not horrible either (and might be partially due to running on GCE, so that effectively we're testing three-level nesting on a fork of upstream KVM!). Enabling it by default seems like a nice way to conclude the 4.20 pull request. :) Unfortunately, enabling nested SVM in 2009 (commit 4b6e4dca701) was a bit premature. However, until live migration support is in place we can reasonably expect that it does not offer much in terms of ABI guarantees. Therefore we are still in time to break things and conform as much as possible to the interface used for VMX. Suggested-by: Jim Mattson Suggested-by: Liran Alon Reviewed-by: Liran Alon Celebrated-by: Liran Alon Celebrated-by: Wanpeng Li Celebrated-by: Wincy Van Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3677609145a4..abeeb45d1c33 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -108,7 +108,7 @@ module_param_named(enable_shadow_vmcs, enable_shadow_vmcs, bool, S_IRUGO); * VMX and be a hypervisor for its own guests. If nested=0, guests may not * use VMX instructions. */ -static bool __read_mostly nested = 0; +static bool __read_mostly nested = 1; module_param(nested, bool, S_IRUGO); static bool __read_mostly nested_early_check = 0; -- cgit v1.2.3-59-g8ed1b