Commit dbee3d02 authored by Linus Torvalds's avatar Linus Torvalds
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KVM: x86: VMX: fix build without hyper-v

Commit ceef7d10 ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap
support") broke the build with Hyper-V disabled, because it accesses
ms_hyperv.nested_features without checking if that exists.

This is the quick-and-hacky build fix.

I suspect the proper fix is to replace the


tests with an inline helper function that also checks that CONFIG_HYPERV
is enabled, since without that, enable_evmcs makes no sense.

But I want a working build environment first and foremost, and I'm upset
this slipped through in the first place.  My primary build tests missed
it because I tend to build with everything enabled, but it should have
been caught in the kvm tree.

Fixes: ceef7d10

 ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap support")
Cc: Vitaly Kuznetsov <>
Cc: Paolo Bonzini <>
Signed-off-by: default avatarLinus Torvalds <>
parent b08fc527
......@@ -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 (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;
return 0;
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