[PATCH] KVM: x86: VMX: fix building without CONFIG_HYPERV

From: Arnd Bergmann
Date: Fri May 25 2018 - 11:38:05 EST


The global ms_hyperv variable is part of the hyperv support, so
we get a link error from accessing it in kernels that have this
turned off:

arch/x86/kvm/vmx.o: In function `alloc_loaded_vmcs':
vmx.c:(.text+0x1654a): undefined reference to `ms_hyperv'
vmx.c:(.text+0x1657a): undefined reference to `ms_hyperv'

This changes the condition to first check the compile-time
configuration symbol to avoid the link error.

Fixes: ceef7d10dfb6 ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap support")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/x86/kvm/vmx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ea098131dcce..e6d6ccab43c3 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4232,7 +4232,8 @@ static int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
goto out_vmcs;
memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);

- if (static_branch_unlikely(&enable_evmcs) &&
+ if (IS_ENABLED(CONFIG_HYPERV) &&
+ static_branch_unlikely(&enable_evmcs) &&
(ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
struct hv_enlightened_vmcs *evmcs =
(struct hv_enlightened_vmcs *)loaded_vmcs->vmcs;
--
2.9.0