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KVM: nSVM: remove useless kvm_clear_*_queue 

For an event to be in injected state when nested_svm_vmrun executes,
it must have come from exitintinfo when svm_complete_interrupts ran:

  vcpu_enter_guest
   static_call(kvm_x86_run) -> svm_vcpu_run
    svm_complete_interrupts
     // now the event went from "exitintinfo" to "injected"
   static_call(kvm_x86_handle_exit) -> handle_exit
    svm_invoke_exit_handler
      vmrun_interception
       nested_svm_vmrun

However, no event could have been in exitintinfo before a VMRUN
vmexit.  The code in svm.c is a bit more permissive than the one
in vmx.c:

        if (is_external_interrupt(svm->vmcb->control.exit_int_info) &&
            exit_code != SVM_EXIT_EXCP_BASE + PF_VECTOR &&
            exit_code != SVM_EXIT_NPF && exit_code != SVM_EXIT_TASK_SWITCH &&
            exit_code != SVM_EXIT_INTR && exit_code != SVM_EXIT_NMI)

but in any case, a VMRUN instruction would not even start to execute
during an attempted event delivery.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2021-08-02 08:52:50 -04:00
parent 4c72ab5aa6
commit db105fab8d
1 changed files with 0 additions and 5 deletions
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5
arch/x86/kvm/svm/nested.c
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@ -659,11 +659,6 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu)
goto out;
}
/* Clear internal status */
kvm_clear_exception_queue(vcpu);
kvm_clear_interrupt_queue(vcpu);
/*
* Since vmcb01 is not in use, we can use it to store some of the L1
* state.