Re: [GIT PULL] KVM changes for 4.18 merge window

[Linus Torvalds]

On Tue, Jun 12, 2018 at 7:03 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> * x86: many bugfixes, implement more Hyper-V super powers,

Uhhuh, I didn't notice this initially, because my basic sanity tests
are with everything enabled, but this breaks the build:

  ERROR: "ms_hyperv" [arch/x86/kvm/kvm-intel.ko] undefined!

The attached patch _may_ be the right thing to do. It's not pretty.

Hmm? And why was this not found before it hit my tree?

                  Linus
 arch/x86/kvm/vmx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fc61e25966e4..d0dd35d582da 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4429,6 +4429,7 @@ static int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
 			goto out_vmcs;
 		memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);
 
+#if IS_ENABLED(CONFIG_HYPERV)
 		if (static_branch_unlikely(&enable_evmcs) &&
 		    (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
 			struct hv_enlightened_vmcs *evmcs =
@@ -4436,6 +4437,8 @@ static int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
 
 			evmcs->hv_enlightenments_control.msr_bitmap = 1;
 		}
+#endif
+
 	}
 	return 0;