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KVM: VMX: return early if msr_bitmap is not supported

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The vmx_msr_filter_changed() may directly/indirectly calls only
vmx_enable_intercept_for_msr() or vmx_disable_intercept_for_msr(). Those
two functions may exit immediately if !cpu_has_vmx_msr_bitmap().

vmx_msr_filter_changed()
-> vmx_disable_intercept_for_msr()
-> pt_update_intercept_for_msr()
   -> vmx_set_intercept_for_msr()
      -> vmx_enable_intercept_for_msr()
      -> vmx_disable_intercept_for_msr()

Therefore, we exit early if !cpu_has_vmx_msr_bitmap().

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20240223202104.3330974-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Dongli Zhang 2024-02-23 12:21:03 -08:00 committed by Sean Christopherson
parent 8e24eeedfd
commit bab22040d7
1 changed files with 3 additions and 0 deletions
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3
arch/x86/kvm/vmx/vmx.c
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@ -4127,6 +4127,9 @@ static void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 i;
if (!cpu_has_vmx_msr_bitmap())
return;
/*
* Redo intercept permissions for MSRs that KVM is passing through to
* the guest. Disabling interception will check the new MSR filter and