Commit db438592 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: VMX: Use vmx_interrupt_blocked() directly from vmx_handle_exit() 



Use vmx_interrupt_blocked() instead of bouncing through
vmx_interrupt_allowed() when handling edge cases in vmx_handle_exit().
The nested_run_pending check in vmx_interrupt_allowed() should never
evaluate true in the VM-Exit path.

Hoist the WARN in handle_invalid_guest_state() up to vmx_handle_exit()
to enforce the above assumption for the !enable_vnmi case, and to detect
any other potential bugs with nested VM-Enter.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-12-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3b82b8d7

arch/x86/kvm/vmx/vmx.c

+10 −9
Original line number Diff line number Diff line
@@ -5285,18 +5285,11 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) 
	bool intr_window_requested;

	unsigned count = 130;



	/*

	 * We should never reach the point where we are emulating L2

	 * due to invalid guest state as that means we incorrectly

	 * allowed a nested VMEntry with an invalid vmcs12.

	 */

	WARN_ON_ONCE(vmx->emulation_required && vmx->nested.nested_run_pending);



	intr_window_requested = exec_controls_get(vmx) &

				CPU_BASED_INTR_WINDOW_EXITING;



	while (vmx->emulation_required && count-- != 0) {

		if (intr_window_requested && vmx_interrupt_allowed(vcpu))

		if (intr_window_requested && !vmx_interrupt_blocked(vcpu))

			return handle_interrupt_window(&vmx->vcpu);



		if (kvm_test_request(KVM_REQ_EVENT, vcpu))
@@ -5913,6 +5906,14 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, 
	if (enable_pml)

		vmx_flush_pml_buffer(vcpu);



	/*

	 * We should never reach this point with a pending nested VM-Enter, and

	 * more specifically emulation of L2 due to invalid guest state (see

	 * below) should never happen as that means we incorrectly allowed a

	 * nested VM-Enter with an invalid vmcs12.

	 */

	WARN_ON_ONCE(vmx->nested.nested_run_pending);



	/* If guest state is invalid, start emulating */

	if (vmx->emulation_required)

		return handle_invalid_guest_state(vcpu);
@@ -5979,7 +5980,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, 


	if (unlikely(!enable_vnmi &&

		     vmx->loaded_vmcs->soft_vnmi_blocked)) {

		if (vmx_interrupt_allowed(vcpu)) {

		if (!vmx_interrupt_blocked(vcpu)) {

			vmx->loaded_vmcs->soft_vnmi_blocked = 0;

		} else if (vmx->loaded_vmcs->vnmi_blocked_time > 1000000000LL &&

			   vcpu->arch.nmi_pending) {

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