From bab22040d7fdeb935e57215a183912ba46eee7f0 Mon Sep 17 00:00:00 2001 From: Dongli Zhang Date: Fri, 23 Feb 2024 12:21:03 -0800 Subject: 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: Dongli Zhang Link: https://lore.kernel.org/r/20240223202104.3330974-3-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/kvm/vmx') diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 05319b74bd3d..5a866d3c2bc8 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -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 -- cgit v1.2.3