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commit3989a6d036upstream. Initialize all per-vCPU AVIC control fields in the VMCB if AVIC is enabled in KVM and the VM has an in-kernel local APIC, i.e. if it's _possible_ the vCPU could activate AVIC at any point in its lifecycle. Configuring the VMCB if and only if AVIC is active "works" purely because of optimizations in kvm_create_lapic() to speculatively set apicv_active if AVIC is enabled *and* to defer updates until the first KVM_RUN. In quotes because KVM likely won't do the right thing if kvm_apicv_activated() is false, i.e. if a vCPU is created while APICv is inhibited at the VM level for whatever reason. E.g. if the inhibit is *removed* before KVM_REQ_APICV_UPDATE is handled in KVM_RUN, then __kvm_vcpu_update_apicv() will elide calls to vendor code due to seeing "apicv_active == activate". Cleaning up the initialization code will also allow fixing a bug where KVM incorrectly leaves CR8 interception enabled when AVIC is activated without creating a mess with respect to whether AVIC is activated or not. Cc: stable@vger.kernel.org Fixes:67034bb9dd("KVM: SVM: Add irqchip_split() checks before enabling AVIC") Fixes:6c3e4422dd("svm: Add support for dynamic APICv") Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org> Reviewed-by: Jim Mattson <jmattson@google.com> Link: https://patch.msgid.link/20260203190711.458413-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>