Commit bab22040 authored by Dongli Zhang's avatar Dongli Zhang Committed by Sean Christopherson
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KVM: VMX: return early if msr_bitmap is not supported 



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: default avatarDongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20240223202104.3330974-3-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 8e24eeed

arch/x86/kvm/vmx/vmx.c

+3 −0
Original line number Diff line number Diff line
@@ -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