On a first glance it isn't obvious why calling kvm_tdp_page_fault() in kvm_mmu_do_page_fault() is special cased, as the general case of using an indirect case would result in calling of kvm_tdp_page_fault() anyway. Add a comment to explain the reason. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> --- arch/x86/kvm/mmu/mmu_internal.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index c98827840e07..a49cd0c438a1 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -322,6 +322,10 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, fault.slot = kvm_vcpu_gfn_to_memslot(vcpu, fault.gfn); } + /* + * With retpoline being active an indirect call is rather expensive, + * so do a direct call in the most common case. + */ if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && fault.is_tdp) r = kvm_tdp_page_fault(vcpu, &fault); else -- 2.43.0
